1
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Abstract
Extra-pair paternity (EPP) benefits to improve the reproductive success via extra-pair fertilizations without the costs of parental care in males and through improved offspring quality with additional food and parental care in females among species of birds. Variations in the EPP appear to link to behavioral and ecological factors and sexual selection. According to the "relationship intelligence hypothesis", the cognitive abilities of the birds play an important role in maintaining long-term relationships. Here, we undertook the first comparative test of the relationships between extra-pair paternity and brain size, testis size, and life histories among 315 species of birds using phylogenetically controlled comparative analyses and path analysis. After controlling for the effects of shared ancestry and body mass, the frequency of EPP was negatively correlated with relative brain size, but positively with testis size across species of birds. However, the frequency of EPP was not linked to life-history traits (e.g. incubation period, fledging period, clutch size, egg mass, and longevity). Our findings suggest that large-brained birds associated with enhanced cognitive abilities are more inclined to maintain long-term stable relationships with their mates and to mutualism with them than to increase the frequency of EPP.
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Affiliation(s)
- Yating Liu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University, Guilin, China.,Guangxi Key Laboratory of Rare and Endangered Animal Ecology, Guangxi Normal University, Guilin, China
| | - Zhengjun Wu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection, Ministry of Education, Guangxi Normal University, Guilin, China.,Guangxi Key Laboratory of Rare and Endangered Animal Ecology, Guangxi Normal University, Guilin, China
| | - Wenbo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, China
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2
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Testing the Role of Natural and Sexual Selection on Testes Size Asymmetry in Anurans. BIOLOGY 2023; 12:biology12020151. [PMID: 36829429 PMCID: PMC9952133 DOI: 10.3390/biology12020151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/14/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023]
Abstract
Directional asymmetry in testes size is commonly documented in vertebrates. The degree of testes size asymmetry has been confirmed to be associated with natural and sexual selection. However, the role of natural and sexual selection driving variations in testes size asymmetry among species of anurans are largely unknown. Here, we studied the patterns of variations in testes size asymmetry and the factors shaping its variations among 116 anuran species. The results indicated that the left size-biased testes in 110 species (94.83% of 116 species) is more common than the right size-biased testes in six species. For all studied species, the degree of testes size asymmetry was positively associated with relative livers and body fat mass, following the prediction of the packaging hypothesis. We also found that the postcopulatory sperm competition (e.g., residual testes size) was positively associated with the degree of testes asymmetry. However, environmental stress (e.g., high latitude, precipitation seasonality and temperature seasonality) did not promote more symmetrical testes for all species. Our findings suggest that both natural selection for larger livers in body space and sexual selection for rapid increase in testis mass for most species during the breeding season can play key roles in driving in testes size asymmetry across anuran species.
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3
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Ito T, Morita M, Okuno S, Inaba K, Shiba K, Munehara H, Koya Y, Homma M, Awata S. Fertilization modes and the evolution of sperm characteristics in marine fishes: Paired comparisons of externally and internally fertilizing species. Ecol Evol 2022; 12:e9562. [PMID: 36479029 PMCID: PMC9720005 DOI: 10.1002/ece3.9562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 12/12/2022] Open
Abstract
Fertilization mode may affect sperm characteristics, such as morphology, velocity, and motility. However, there is little information on how fertilization mode affects sperm evolution because several factors (e.g., sperm competition) are intricately intertwined when phylogenetically distant species are compared. Here, we investigated sperm characteristics by comparing seven externally and four internally fertilizing marine fishes from three different groups containing close relatives, considering sperm competition levels. The sperm head was significantly slenderer in internal fertilizers than in external fertilizers, suggesting that a slender head is advantageous for swimming in viscous ovarian fluid or in narrow spaces of the ovary. In addition, sperm motility differed between external and internal fertilizers; sperm of external fertilizers were only motile in seawater, whereas sperm of internal fertilizers were only motile in an isotonic solution. These results suggest that sperm motility was adapted according to fertilization mode. By contrast, total sperm length and sperm velocity were not associated with fertilization mode, perhaps because of the different levels of sperm competition. Relative testis mass (an index of sperm competition level) was positively correlated with sperm velocity and negatively correlated with the ratio of sperm head length to total sperm length. These findings suggest that species with higher levels of sperm competition have faster sperm with longer flagella relative to the head length. These results contradict the previous assumption that the evolution of internal fertilization increases the total sperm length. In addition, copulatory behavior with internal insemination may involve a large genital morphology, but this is not essential in fish, suggesting the existence of various sperm transfer methods. Although the power of our analyses is not strong because of the limited number of species, we propose a new scenario of sperm evolution in which internal fertilization would increase sperm head length, but not total sperm length, and change sperm motility.
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Affiliation(s)
- Takeshi Ito
- Department of Biology, Graduate School of ScienceOsaka Metropolitan UniversityOsakaJapan
- Department of Biology and Geosciences, Graduate School of ScienceOsaka City UniversityOsakaJapan
| | - Masaya Morita
- Sesoko Station, Tropical Biosphere Research CenterUniversity of the RyukyusMotobuJapan
| | - Seiya Okuno
- Department of Biology, Graduate School of ScienceOsaka Metropolitan UniversityOsakaJapan
- Department of Biology and Geosciences, Graduate School of ScienceOsaka City UniversityOsakaJapan
| | - Kazuo Inaba
- Shimoda Marine Research CenterUniversity of TsukubaShimodaJapan
| | - Kogiku Shiba
- Shimoda Marine Research CenterUniversity of TsukubaShimodaJapan
| | - Hiroyuki Munehara
- Usujiri Fisheries Station, Field Science Center for Northern BiosphereHokkaido UniversityHakodateJapan
| | - Yasunori Koya
- Department of Biology, Faculty of EducationGifu UniversityGifuJapan
| | | | - Satoshi Awata
- Department of Biology, Graduate School of ScienceOsaka Metropolitan UniversityOsakaJapan
- Department of Biology and Geosciences, Graduate School of ScienceOsaka City UniversityOsakaJapan
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4
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Valchi P, Ponssa ML, Farías A, Volonteri MC, Hermida GN. Comparative spermatozoa ultrastructure of neotropical grass frogs (genus Leptodactylus) with comments on anuran reproductive modes and phylogeny. ZOOL ANZ 2022. [DOI: 10.1016/j.jcz.2022.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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5
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Jiang Y, Zhao L, Luan X, Liao W. Testis Size Variation and Its Environmental Correlates in Andrew's Toad ( Bufo andrewsi). Animals (Basel) 2022; 12:3011. [PMID: 36359135 PMCID: PMC9657756 DOI: 10.3390/ani12213011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 10/31/2022] [Accepted: 11/01/2022] [Indexed: 08/27/2023] Open
Abstract
Reproductive investments influenced by environmental conditions vary extensively among geographically distinct populations. However, investigations of patterns of intraspecific variation in male reproductive investments and the mechanisms shaping this variation in anurans remain scarce. Here, we focused on the variation in testis size in 14 populations of the Andrew's toad Bufo andrewsi, a species with weak dispersal ability but wide distribution in southwestern China, to establish whether male reproductive investment varies on an environmental gradient. Our analysis revealed a significant variation in relative testis size across populations, and a positive correlation between testis size and body condition. We, however, found no geographic trends explaining the variability in the testis size. The relative testis size did not increase with increasing latitude or altitude. We also found no relationship between relative testis size and rainfall, but a negative correlation with the coefficient of variation of temperature, with larger testes under stable environments. These findings suggest that the decreased male reproductive investment of this species may be a consequence of harsher or fluctuating environmental conditions.
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Affiliation(s)
- Ying Jiang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
- Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong 637009, China
| | - Li Zhao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
- Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong 637009, China
| | - Xiaofeng Luan
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China
| | - Wenbo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
- Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong 637009, China
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6
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Bordin RO, Dos Santos Fernandes CE, Franco-Belussi L, Ribeiro Farias Leão T, Sanabria M. Sperm morphology and testicular histology of the polyandric species Leptodactylus podicipinus (Anura: Leptodactylidae) from an urban environment. Anat Rec (Hoboken) 2022; 305:3532-3542. [PMID: 35365960 DOI: 10.1002/ar.24928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/15/2022] [Accepted: 03/15/2022] [Indexed: 11/11/2022]
Abstract
Anurans have a high reproductive diversity, which is closely associated with testicular dynamics and sperm production. This variety in reproduction is modulated by the sexual characteristics of reproductive strategies, such as polyandry. Leptodactylus podicipinus has high reproductive plasticity, wide geographical distribution, and polyandric behavior. Although aspects of the testes and sperm of this species are known, knowledge about the relationship between these aspects and reproductive investment is scarce. The present study evaluated the morphological characteristics of the testes and sperm in an urban environment. We used 11 sexually mature males from the city of Campo Grande, Mato Grosso do Sul, Brazil. The specimens were obtained from night excursions between April and September; the months that constitute the post-rainy season. The biometric data (snout-vent length, testes, and body mass) were associated with sperm parameters (length of the spermatozoon head and tail). Stereological analyses of sperm morphology and the testes were performed. The results showed correlations between testis mass and spermatozoon length, which were positively related to head length and negatively related to tail length. The locular area and tail length were also negatively correlated. The percentage of normal spermatozoa was 97%; however, some sperm heads and tails exhibited different morphologies from the pattern described for the species. The germinative structure comprised more than 50% of the locular area composed of spermatozoa. The results of this study contribute to the knowledge of aspects related to the reproductive biology of L. podicipinus obtained from an urban environment.
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Affiliation(s)
- Rafael Oliveira Bordin
- Programa de pós graduação em Biologia Animal, Universidade Federal de Mato Grosso do Sul, 79070-900, Campo Grande, MS, Brasil
| | - Carlos Eurico Dos Santos Fernandes
- Laboratório de Patologia Experimental (LAPEx), Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Brasil
| | - Lilian Franco-Belussi
- Laboratório de Patologia Experimental (LAPEx), Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, Campo Grande, Brasil
| | - Taynara Ribeiro Farias Leão
- Programa de pós graduação em Biodiversidade, Universidade Estadual Paulista, São José do Rio Preto, SP, Brasil
| | - Marciana Sanabria
- Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, 79070-900, Campo Grande, Brasil
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7
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Ito T, Kinoshita I, Tahara D, Goto A, Tojima S, Sideleva VG, Kupchinsky AB, Awata S. Fertilization modes drive the evolution of sperm traits in Baikal sculpins. J Zool (1987) 2021. [DOI: 10.1111/jzo.12867] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- T. Ito
- Department of Biology and Geosciences Graduate School of Science Osaka City University Osaka Japan
| | - I. Kinoshita
- Usa Marine Biological InstituteKochi University Kochi Japan
| | - D. Tahara
- Research Center for Marine Bioresources Fukui Prefectural University Fukui Japan
| | - A. Goto
- Department of Science of Environmental Education Hokkaido University of Education Hokkaido Japan
| | - S. Tojima
- Usa Marine Biological InstituteKochi University Kochi Japan
| | - V. G. Sideleva
- Zoological InstituteThe Russian Academy of Sciences Saint Petersburg Russia
| | - A. B. Kupchinsky
- Siberian Branch Baikal MuseumIrkutsk Scientific CenterRussian Academy of Sciences Listvyanka Russia
| | - S. Awata
- Department of Biology and Geosciences Graduate School of Science Osaka City University Osaka Japan
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8
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Watt AM, Marcec-Greaves R, Hinkson KM, Poo S, Roberts B, Pitcher TE. Effects of age on sperm quality metrics in endangered Mississippi gopher frogs (Lithobates sevosus) from captive populations used for controlled propagation and reintroduction efforts. Zoo Biol 2021; 40:218-226. [PMID: 33606315 DOI: 10.1002/zoo.21594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/08/2021] [Indexed: 01/13/2023]
Abstract
A decline in sperm quality with age is a common prediction of senescence-based hypotheses and empirical studies. While widely studied across taxa, there is little known on the effect of ageing on sperm quality in amphibians, especially in captive populations used for controlled propagation and reintroduction efforts. Here, we investigated variation in sperm quality metrics (i.e., motility, concentration, and morphology) in the endangered Mississippi gopher frog (Lithobates sevosus) among males of three age categories using individuals from captive breeding populations housed at three different zoological institutions. Different aged males across the species expectant lifespan (1-9, 1-2, 3-4, and 8-9-year-old subcategories) were chosen in an attempt to identify an optimal breeding age relevant for captive breeding programs. Moreover, we explored and statistically controlled for potential differences in sperm quality which may be attributed to the type of induction hormones and source populations that differed among institutions. Results indicated that males of different ages did not differ in sperm motility or concentration. However, we did find that older males (8-9 years old) had significantly longer sperm than other age categories and younger males (1-2 years old) had significantly more atypical sperm than other age categories. Furthermore, we found no significant differences in any sperm quality metrics between the different induction hormones or source populations used at the different institutions. Within a captive breeding program, this information is especially valuable as our results indicate that males that have only recently sexually matured may not be ready to breed, while older males maintain sperm quality metrics presumably related to fertilization success.
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Affiliation(s)
- Ashley M Watt
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada
| | - Ruth Marcec-Greaves
- National Amphibian Conservation Center, Detroit Zoological Society, Royal Oak, Michigan, USA
| | - Kristin M Hinkson
- Department of Conservation and Research, Memphis Zoological Society, Memphis, Tennessee, USA
| | - Sinlan Poo
- Department of Conservation and Research, Memphis Zoological Society, Memphis, Tennessee, USA
| | - Beth Roberts
- Department of Conservation and Research, Memphis Zoological Society, Memphis, Tennessee, USA
| | - Trevor E Pitcher
- Department of Integrative Biology, University of Windsor, Windsor, Ontario, Canada.,Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada
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9
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Rudin-Bitterli TS, Mitchell NJ, Evans JP. Extensive geographical variation in testes size and ejaculate traits in a terrestrial-breeding frog. Biol Lett 2020; 16:20200411. [PMID: 32991823 PMCID: PMC7532705 DOI: 10.1098/rsbl.2020.0411] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/08/2020] [Indexed: 11/12/2022] Open
Abstract
Ejaculate traits vary extensively among individuals and species, but little is known about their variation among populations of the same species. Here, we investigated patterns of intraspecific variation in male reproductive investment in the terrestrial-breeding frog Pseudophryne guentheri. Like most anurans, breeding activity in P. guentheri is cued by precipitation, and therefore the timing and duration of breeding seasons differ among geographically separated populations, potentially leading to differences in the level of sperm competition. We, therefore, anticipated local adaptation in sperm traits that reflect these phenological differences among populations. Our analysis of six natural populations across a rainfall gradient revealed significant divergence in testes and ejaculate traits that correspond with annual rainfall and rainfall seasonality; males from the northern and drier edge of the species range had significantly smaller testes containing fewer, smaller and less motile sperm compared with those from mesic central populations. These findings may reflect spatial variation in the strength of postcopulatory sexual selection, likely driven by local patterns of precipitation.
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Affiliation(s)
| | | | - Jonathan P. Evans
- School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
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10
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Liao WB, Zhong MJ, Lüpold S. Sperm quality and quantity evolve through different selective processes in the Phasianidae. Sci Rep 2019; 9:19278. [PMID: 31848414 PMCID: PMC6917726 DOI: 10.1038/s41598-019-55822-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/03/2019] [Indexed: 11/09/2022] Open
Abstract
Sperm competition is often considered the primary selective force underlying the rapid and diversifying evolution of ejaculate traits. Yet, several recent studies have drawn attention to other forms of selection with the potential of exceeding the effects of sperm competition. Since ejaculates are complex, multivariate traits, it seems plausible that different ejaculate components vary in their responses to different selective pressures. Such information, however, is generally lacking as individual ejaculate traits tend to be studied in isolation. Here, we studied the macroevolutionary patterns of ejaculate volume, sperm number, sperm length and the proportion of viable normal sperm in response to varying levels of sperm competition, body size and the duration of female sperm storage in pheasants and allies (Phasianidae). Ejaculate volume, sperm number and sperm viability were all relatively higher in polygamous than in monogamous mating systems. However, whereas ejaculate volume additionally covaried with body size, sperm number instead increased with the female sperm-storage duration, in conjunction with a decrease in sperm length. Overall, our results revealed important details on how different forms of selection can jointly shape ejaculates as complex, composite traits.
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Affiliation(s)
- Wen Bo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China. .,Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong, Sichuan, 637009, China. .,Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China.
| | - Mao Jun Zhong
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China.,Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong, Sichuan, 637009, China.,Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, 8057, Zurich, Switzerland
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11
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Turani B, Aliko V, Shkembi E. Characterization of Albanian water frog, Pelophylax shqipericus, sperm traits and morphology, by using phase contrast microscopy. Microsc Res Tech 2019; 82:1802-1809. [PMID: 31313452 DOI: 10.1002/jemt.23346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 05/28/2019] [Accepted: 06/13/2019] [Indexed: 11/10/2022]
Abstract
Mature spermatozoa traits and morphology of endangered Albanian water frog, Pelophylax shqipericus, have been characterized for the first time through phase contrast microscopy, as part of successful implementation of in vitro fertilization technique for this species. The basic morphology of P. shqipericus spermatozoa consists of an elongated, thick, smooth-edged, and solid-staining head, continuing with a thin and long tail which usually extends 2.48 times the head length. The acrosome was not clearly discernible so the measurements were done on the head as a whole, while the middle section was better visible. Average length of head, including the acrosome and midsection was estimated to be 11.78 μm ± 0.32, while the tail length resulted 29.24 ± 1.75 μm. The average thickness of the head was shown to be 3.45 μm. The total sperm length resulted to be 41.02 ± 1.83 μm. The average sperm concentration was estimated of 25.5 × 106 /ml. Sperm amount, survival rate and motility were also measured. The sperm survival rate was maximal immediately after preparation of the suspension and tended to decrease over time of storage, reaching 50% after 72 hr. Decreased sperm motility seemed to follow the same trend as sperm viability. Sperm traits resulted to be very similar both in size and in shape with those of "Lessonae" frog group, one of the lineages of Western Palearctic species complex, suggesting a strong phylogenetic relationship among these species.
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Affiliation(s)
- Blerta Turani
- University of Tirana, Faculty of Natural Sciences, Tirana, Albania
| | - Valbona Aliko
- University of Tirana, Faculty of Natural Sciences, Tirana, Albania
| | - Entela Shkembi
- Semiology Laboratory, Medical Center, Dani Andrology, Tirana, Albania
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12
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13
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Dzyuba V, Sampels S, Ninhaus-Silveira A, Kahanec M, Veríssimo-Silveira R, Rodina M, Cosson J, Boryshpolets S, Selinger M, Sterba J, Dzyuba B. Sperm motility and lipid composition in internally fertilizing ocellate river stingray Potamotrygon motoro. Theriogenology 2019; 130:26-35. [PMID: 30856412 DOI: 10.1016/j.theriogenology.2019.02.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/24/2019] [Indexed: 01/13/2023]
Abstract
All extant groups of Elasmobranches have internal fertilization and the structure of the male reproductive organs is very specific: sperm passes from the internal organs via the cloaca, but the male copulating organ (clasper) is distant from the cloaca. This suggests that sperm can contact the surrounding medium before fertilization. Because of this involvement with the environment, external signaling in sperm motility activation could occur in these species even though their fertilization mode is internal. In this case, spermatozoa of Elasmobranches should hypothetically possess a specific structure and membrane lipid composition which supports physiological functions of the sperm associated with environmental tonicity changes occurring at fertilization. Additionally, sperm motility properties in these taxa are poorly understood. The current study examined sperm lipid composition and motility under different environmental conditions for the ocellate river stingray, Potamotrygon motoro, an endemic South America freshwater species. Sperm samples were collected from six mature males during the natural spawning period. Sperm motility was examined in seminal fluid and fresh water by light video microscopy. Helical flagellar motion was observed in seminal fluid and resulted in spermatozoon progression; however, when diluted in fresh water, spermatozoa were immotile and had compromised structure. Lipid class and fatty acid (FA) composition of spermatozoa was analyzed by thin layer and gas chromatography. Spermatozoa FAs consisted of 33 ± 1% saturated FAs, 28 ± 1% monounsaturated FAs (MUFAs), and 41 ± 1% polyunsaturated FAs (PUFAs), and a high content of n-6 FAs (32 ± 2%) was measured. These results allowed us to conclude that sperm transfer from P. motoro male into female should occur without coming into contact with the hypotonic environment so as to preserve potent motility. In addition, this unusual reproductive strategy is associated with specific spermatozoa structure and lipid composition. Low level of docosahexaenoic acid and relatively low PUFA/MUFA ratio probably account for the relatively low fluidity of freshwater stingray membrane and can be the main reason for its low tolerance to hypotonicity.
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Affiliation(s)
- Viktoriya Dzyuba
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Sabine Sampels
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic; Swedish University of Agricultural Sciences, Department of Molecular Sciences, PO Box 7015, 75007, Uppsala, Sweden
| | - Alexandre Ninhaus-Silveira
- São Paulo State University, Ilha Solteira, Faculty of Engineering, Department of Biology and Zootechny, Neotropical Ichthyology Laboratory - LINEO, Monção Street, 226, 15385-000, Ilha Solteira, SP, Brazil
| | - Martin Kahanec
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Rosicleire Veríssimo-Silveira
- São Paulo State University, Ilha Solteira, Faculty of Engineering, Department of Biology and Zootechny, Neotropical Ichthyology Laboratory - LINEO, Monção Street, 226, 15385-000, Ilha Solteira, SP, Brazil
| | - Marek Rodina
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Jacky Cosson
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Sergii Boryshpolets
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Martin Selinger
- University of South Bohemia in České Budějovice, Faculty of Science, Institute of Chemistry, Branišovská 1760, 370 05, České Budějovice, Czech Republic; Biology Centre of Czech Academy of Sciences, Institute of Parasitology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Jan Sterba
- University of South Bohemia in České Budějovice, Faculty of Science, Institute of Chemistry, Branišovská 1760, 370 05, České Budějovice, Czech Republic; Biology Centre of Czech Academy of Sciences, Institute of Parasitology, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Borys Dzyuba
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25, Vodňany, Czech Republic.
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14
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Cai YL, Mai CL, Yu X, Liao WB. Effect of population density on relationship between pre- and postcopulatory sexual traits. ANIM BIOL 2019. [DOI: 10.1163/15707563-20181057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Sexual selection theory states that the premating (ornaments and armaments) sexual traits should trade off with the postmating (testes and ejaculates) sexual traits, assuming that growing and maintaining these traits is expensive and that total reproductive investments are limited. Male-male competition and sperm competition are predicted to affect how males allocate their finite resources to these traits. Here, we studied relative expenditure on pre- and postmating sexual traits among 82 species for three mammalian orders with varying population density using comparative phylogenetic analysis. The results showed that population density affected sexual size dimorphism (SSD) in both Artiodactyla and Carnivora, but not in Primates. However, relative testis mass and sperm size were not affected by population density. Moreover, we did not find associations between the SSD and testis mass or sperm size in three taxonomic groups. The interspecific relationships between pre- and postcopulatory sexual traits did not change with increased population density. Our findings suggest that population density did not affect variation in the relationship between pre- and postcopulatory sexual traits for these three mammalian orders.
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Affiliation(s)
- Yun Lin Cai
- 1Department of Urology, the Second Clinical Medical College of North Sichuan Medical College, Nanchong, 637000, China
| | - Chun Lan Mai
- 2Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, China
| | - Xin Yu
- 2Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, China
| | - Wen Bo Liao
- 2Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, China
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15
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Zhang L, An D, He Y, Li Z, Fang B, Chen X, Lu X. Variation in testis weight of the Tibetan toad Scutiger boulengeri along a narrow altitudinal gradient. ANIM BIOL 2018. [DOI: 10.1163/15707563-17000016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Life-history theory predicts that organisms inhabiting harsh environments such as high altitudes should invest less in reproduction and more in survival. Testis size is associated with the intensity of male-male competition for mating and thus may be treated as an indicator of male reproductive investment. Hence, it may be expected that organisms will reduce their testis size with increasingly harsh environments. Here we test this prediction in a toad species, Scutiger boulengeri, endemic to the Tibetan plateau using data from three populations located at altitudes of 4078, 4276, and 4387 m. Consistent with the prediction, male toads exhibited smaller testes at higher altitudes, despite the relatively narrow altitudinal span. It is likely that cold climates and strong seasonality constrain the ability of high-altitude male toads to allocate more energy into reproduction, thereby leading to small testis size. In addition, the left testis was significantly heavier than the right one and the degree of size asymmetry was unrelated to either altitude or body condition.
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Affiliation(s)
- Lixia Zhang
- 1Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Dong An
- 1Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Yuxiao He
- 1Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Zhibing Li
- 1Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Bohao Fang
- 2Department of Ecology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Xiaohong Chen
- 1Department of Ecology, College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Xin Lu
- 2Department of Ecology, College of Life Sciences, Wuhan University, Wuhan 430072, China
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16
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Tang T, Luo Y, Huang CH, Liao WB, Huang WC. Variation in somatic condition and testis mass in Feirana quadranus along an altitudinal gradient. ANIM BIOL 2018. [DOI: 10.1163/15707563-17000142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Abstract
The competition for fertilization among sperm from different males can drive variation in male reproductive investments. However, the mechanisms shaping reproductive allocation and the resulting variations in reproductive investment relative to environmental variables such as resource availability and male-male competition remain poorly known in frogs. Here, we investigated inter-population variation in male somatic condition and testis mass across four populations of the swelled vent frog Feirana quadranus along an altitudinal gradient. We found that relative testis mass did not increase with altitude, which was inconsistent with previous predictions that an increase in latitude and/or altitude should result in decreased sperm production in anurans due to shortened breeding seasons and the decline in resource availability. We also found no increase in somatic condition and male/female operational sex ratio with altitude. However, the somatic condition exhibited a positive correlation with testis mass, which indicated the condition-dependent testis size in F. quadranus. Moreover, an increase of testis mass with increasing male/female operational sex ratio suggest that male-male competition can result in an increased intensity of sperm competition, thereby increasing testis mass.
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Affiliation(s)
- Tao Tang
- 1Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China
- 2Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Yi Luo
- 1Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China
- 2Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Chun Hua Huang
- 1Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China
- 2Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Wen Bo Liao
- 1Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, Sichuan, China
- 2Institute of Eco-adaptation in Amphibians and Reptiles, China West Normal University, Nanchong, 637009, Sichuan, China
| | - Wen Chao Huang
- 3Science and Technology Department of Sichuan Province, Chengdu, 610000, Sichuan, China
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17
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Liao WB, Huang Y, Zeng Y, Zhong MJ, Luo Y, Lüpold S. Ejaculate evolution in external fertilizers: Influenced by sperm competition or sperm limitation? Evolution 2017; 72:4-17. [PMID: 28975611 DOI: 10.1111/evo.13372] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 12/19/2022]
Abstract
The evolution of sperm quality and quantity is shaped by various selective processes, with sperm competition generally considered the primary selective agent. Particularly in external fertilizers, however, sperm limitation through gamete dispersal can also influence gamete investments, but empirical data examining this effect are limited. Here, we studied the relative importance of sperm competition and the spawning conditions in explaining the macroevolutionary patterns of sperm size and number within two taxa with external fertilization but differences in their reproductive biology. In frogs, sperm swim slowly but for up to hours as they penetrate the gelatinous egg coating, whereas fish sperm typically swim fast, are very short-lived (seconds to minutes), and often face a relatively higher risk of being moved away from the ova by currents. Our phylogenetic models and path analyses revealed different trajectories of ejaculate evolution in these two taxa. Sperm size and number responded primarily to variation in sperm competition in the anurans, but more strongly to egg number and water turbulence in the fishes. Whereas the results across anurans align with the general expectation that sexual selection is the main driver of ejaculate evolution, our findings across the fishes suggest that sperm limitation has been underappreciated.
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Affiliation(s)
- Wen Bo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, Sichuan, China
| | - Yan Huang
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, Sichuan, China
| | - Yu Zeng
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, Sichuan, China
| | - Mao Jun Zhong
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, Sichuan, China
| | - Yi Luo
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, Sichuan, China
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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18
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Godwin JL, Vasudeva R, Michalczyk Ł, Martin OY, Lumley AJ, Chapman T, Gage MJG. Experimental evolution reveals that sperm competition intensity selects for longer, more costly sperm. Evol Lett 2017; 1:102-113. [PMID: 30283643 PMCID: PMC6089504 DOI: 10.1002/evl3.13] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/24/2017] [Accepted: 05/02/2017] [Indexed: 12/12/2022] Open
Abstract
It is the differences between sperm and eggs that fundamentally underpin the differences between the sexes within reproduction. For males, it is theorized that widespread sperm competition leads to selection for investment in sperm numbers, achieved by minimizing sperm size within limited resources for spermatogenesis in the testis. Here, we empirically examine how sperm competition shapes sperm size, after more than 77 generations of experimental selection of replicate lines under either high or low sperm competition intensities in the promiscuous flour beetle Tribolium castaneum. After this experimental evolution, populations had diverged significantly in their sperm competitiveness, with sperm in ejaculates from males evolving under high sperm competition intensities gaining 20% greater paternity than sperm in ejaculates from males that had evolved under low sperm competition intensity. Males did not change their relative investment into sperm production following this experimental evolution, showing no difference in testis sizes between high and low intensity regimes. However, the more competitive males from high sperm competition intensity regimes had evolved significantly longer sperm and, across six independently selected lines, there was a significant association between the degree of divergence in sperm length and average sperm competitiveness. To determine whether such sperm elongation is costly, we used dietary restriction experiments, and revealed that protein-restricted males produced significantly shorter sperm. Our findings therefore demonstrate that sperm competition intensity can exert positive directional selection on sperm size, despite this being a costly reproductive trait.
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Affiliation(s)
- Joanne L. Godwin
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Ramakrishnan Vasudeva
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | | | | | - Alyson J. Lumley
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Tracey Chapman
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
| | - Matthew J. G. Gage
- School of Biological SciencesUniversity of East AngliaNorwich Research ParkNorwichNR4 7TJUnited Kingdom
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19
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Lüpold S, Jin L, Liao WB. Population density and structure drive differential investment in pre- and postmating sexual traits in frogs. Evolution 2017; 71:1686-1699. [PMID: 28394412 DOI: 10.1111/evo.13246] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/25/2017] [Indexed: 01/01/2023]
Abstract
Sexual selection theory predicts a trade-off between premating (ornaments and armaments) and postmating (testes and ejaculates) sexual traits, assuming that growing and maintaining these traits is costly and that total reproductive investments are limited. The number of males in competition, the reproductive gains from investing in premating sexual traits, and the level of sperm competition are all predicted to influence how males allocate their finite resources to these traits. Yet, empirical examination of these predictions is currently scarce. Here, we studied relative expenditure on pre- and postmating sexual traits among frog species varying in their population density, operational sex ratio, and the number of competing males for each clutch of eggs. We found that the intensifying struggle to monopolize fertilizations as more and more males clasp the same female to fertilize her eggs shifts male reproductive investment toward sperm production and away from male weaponry. This shift, which is mediated by population density and the associated level of male-male competition, likely also explains the trade-off between pre- and postmating sexual traits in our much broader sample of anuran species. Our results highlight the power of such a multilevel approach in resolving the evolution of traits and allocation trade-offs.
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Affiliation(s)
- Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich-Irchel, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Long Jin
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, P. R. China
| | - Wen Bo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, 637009, P. R. China
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20
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Mai CL, Liu YH, Jin L, Mi ZP, Liao WB. Altitudinal variation in somatic condition and reproductive investment of male Yunnan pond frogs (Dianrana pleuraden). ZOOL ANZ 2017. [DOI: 10.1016/j.jcz.2016.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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21
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Wang W, Zhang R, Yin Q, Zhang S, Li W, Li D, Mi Z. Digestive tract length is positively correlated with altitude across Fejervarya limnocharis populations. ANIM BIOL 2017. [DOI: 10.1163/15707563-00002534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In animals, the amount of nutrients acquired through foraging and the proportion of metabolisable energy gained is reflected in the digestive tract length. This digestion theory predicts that the consumption of food with high content of indigestible material will lead to increased gut dimensions. Here, we analyzed geographic variation in digestive tract length related to diet among 14 Fejervarya limnocharis populations to test the digestion theory. Relative digestive tract length significantly differed between males and females and among populations. The relative length of the digestive tract increased with altitude. We also found a positive correlation between the proportion of plant material and digestive tract length for both sexes, which is consistent with the prediction of the digestion theory. Our findings suggest that variation in temperature associated with altitude affects food composition, and, thereby ultimately gut morphology of individuals.
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Affiliation(s)
- Wei Yu Wang
- 1College of Wildlife Resources, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
- 2College of Life Science and Agriculture Forestry, Qiqihar University, Wenhua Street 42, Qiqihar 161006, China
| | - Rong Zhang
- 3Micangshan Nature Reserve, Wangcang, 628200, Sichuan, China
| | - Qing Xiao Yin
- 3Micangshan Nature Reserve, Wangcang, 628200, Sichuan, China
| | - Shi Peng Zhang
- 3Micangshan Nature Reserve, Wangcang, 628200, Sichuan, China
| | - Wen Qin Li
- 4Key Laboratory of Southwest China, Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Da Yong Li
- 4Key Laboratory of Southwest China, Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Zhi Ping Mi
- 4Key Laboratory of Southwest China, Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
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22
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Liao WB, Lou SL, Zeng Y, Kotrschal A. Large Brains, Small Guts: The Expensive Tissue Hypothesis Supported within Anurans. Am Nat 2016; 188:693-700. [DOI: 10.1086/688894] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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23
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SCHREMPF A, MOSER A, DELABIE J, HEINZE J. Sperm traits differ between winged and wingless males of the antCardiocondyla obscurior. Integr Zool 2016; 11:427-432. [DOI: 10.1111/1749-4877.12191] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Alexandra SCHREMPF
- Zoology/Evolutionary Biology; University of Regensburg; Regensburg Germany
| | - Astrid MOSER
- Zoology/Evolutionary Biology; University of Regensburg; Regensburg Germany
| | - Jacques DELABIE
- Myrmecological Laboratory; Cocoa Research Center CEPLAC; Itabuna Brazil
| | - Jürgen HEINZE
- Zoology/Evolutionary Biology; University of Regensburg; Regensburg Germany
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24
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Smith RJ, Matzke-Karasz R, Kamiya T. Sperm length variations in five species of cypridoidean non-marine ostracods (Crustacea). Cell Tissue Res 2016; 366:483-497. [PMID: 27449928 DOI: 10.1007/s00441-016-2459-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/17/2016] [Indexed: 11/25/2022]
Abstract
Spermatozoa of the ostracod superfamily Cypridoidea include some of the longest in the animal kingdom, but unlike other so-called giant spermatozoa, they are aflagellate, probably evolved only once, and represent an exceptionally old trait. Sperm length variations within cypridoidean species remain poorly known, a lack that hinders the development of hypotheses to explain their length and variation. For this study, the lengths of 500 spermatozoa from each of five species of freshwater cypridoidean ostracods, Candonopsis tenuis (Brady, 1886), Fabaeformiscandona subacuta (Yang, 1982), Heterocypris rotundata (Bronshtein, 1928), Ilyocypris japonica Okubo, 1990, and Notodromas trulla Smith and Kamiya, 2014, were measured, including the lengths of the posterior and anterior regions. No overall pattern in sperm variation was discernible. Length variations between species, between males of the same species, and within individual males varied from low (Candonopsis tenuis) to extraordinarily large (Notodromas trulla and Fabaeformiscandona subacuta). Sperm competition, cryptic female choice, sperm heteromorphism, and testis size are unlikely to explain all of the variations observed. Age structures of the populations sampled might play a role in explaining some intraspecific variation. The differing amounts of variation in sperm characters revealed in this study suggest that multiple evolutionary trends and pressures shape sperm lengths in this superfamily.
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Affiliation(s)
- Robin J Smith
- Lake Biwa Museum, Oroshimo 1091, Kusatsu, Shiga Prefecture, 525-0001, Japan.
| | - Renate Matzke-Karasz
- Department of Earth and Environmental Sciences, Palaeontology, Ludwig-Maximilians-Universität München and GeoBio-Center LMU, 80333, Munich, Germany.
| | - Takahiro Kamiya
- College of Science and Engineering, School of Natural System, University of Kanazawa, Kakuma, Kanazawa, 920-1192, Japan
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25
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Zeng Y, Lou SL, Liao WB, Jehle R, Kotrschal A. Sexual selection impacts brain anatomy in frogs and toads. Ecol Evol 2016; 6:7070-7079. [PMID: 28725383 PMCID: PMC5513231 DOI: 10.1002/ece3.2459] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 07/20/2016] [Accepted: 08/18/2016] [Indexed: 11/10/2022] Open
Abstract
Natural selection is a major force in the evolution of vertebrate brain size, but the role of sexual selection in brain size evolution remains enigmatic. At least two opposing schools of thought predict a relationship between sexual selection and brain size. Sexual selection should facilitate the evolution of larger brains because better cognitive abilities may aid the competition for mates. However, it may also restrict brain size evolution due to energetic trade‐offs between brain tissue and sexually selected traits. Here, we examined the patterns of selection on brain size and brain anatomy in male anurans (frogs and toads), a group where the strength of sexual selection differs markedly among species, using a phylogenetically controlled generalized least‐squared (PGLS) regression analyses. The analysis revealed that in 43 Chinese anuran species, neither mating system, nor type of courtship, or testes mass was significantly associated with relative brain size. While none of those factors related to the relative size of olfactory nerves, optic tecta, telencephalon, and cerebellum, the olfactory bulbs were relatively larger in monogamous species and those using calls during courtship. Our findings support the mosaic model of brain evolution and suggest that while the investigated aspects of sexual selection do not seem to play a prominent role in the evolution of brain size of anurans, they do impact their brain anatomy.
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Affiliation(s)
- Yu Zeng
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong Sichuan China
| | - Shang Ling Lou
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong Sichuan China
| | - Wen Bo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong Sichuan China
| | - Robert Jehle
- School of Environment & Life Sciences University of Salford Salford UK
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26
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Altitude underlies variation in the mating system, somatic condition, and investment in reproductive traits in male Asian grass frogs (Fejervarya limnocharis). Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2128-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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27
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Jin L, Mi ZP, Liao WB. Altitudinal variation in male reproductive investment in a polyandrous frog species (Hyla gongshanensis jingdongensis). ANIM BIOL 2016. [DOI: 10.1163/15707563-00002505] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Competition for fertilization in multi-male group spawning can drive variation in male reproductive investment (i.e., testis mass and sperm size). Inter-population comparisons of variation in energetic availability and allocation along geographical gradients allow insights into the mechanisms shaping the reproductive investments of animals. Although inter-population differences in female reproductive investment (i.e., clutch size and egg size) have been studied extensively across a wide range of taxa, little information on variation in reproductive investment in males is available. Here, we studied altitudinal variation in testis mass and sperm length among three populations in the Jingdong tree frog (Hyla gongshanensis jingdongensis), a polyandrous species, in Yunnan Province in China. The results showed that individuals exhibited smaller testes at higher altitudes while testes mass was positively correlated with body size, body condition and age. Longer sperm length was observed in the middle-altitude population. Moreover, we found that sperm number was positively correlated with testes mass and sperm length. Our correlational findings suggest that environmental constraints at high altitude select for less investment in testes and offspring number.
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Affiliation(s)
- Long Jin
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Zhi Ping Mi
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
| | - Wen Bo Liao
- Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China
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28
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Salles NME, Zara FJ, Prado CPA. Differences in sperm morphology in foam-nesting leptodactyline frogs (Anura, Leptodactylidae). ACTA ZOOL-STOCKHOLM 2015. [DOI: 10.1111/azo.12144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Natália M. E. Salles
- Programa de Pós-Graduação em Ciências Biológicas (Zoologia); Instituto de Biociências; Universidade Estadual Paulista; 13506-900 Rio Claro São Paulo Brazil
| | - Fernando J. Zara
- Departamento de Biologia Aplicada; Faculdade de Ciências Agrárias e Veterinárias; Universidade Estadual Paulista; 14884-900 Jaboticabal São Paulo Brazil
| | - Cynthia P. A. Prado
- Departamento de Morfologia e Fisiologia Animal; Faculdade de Ciências Agrárias e Veterinárias; Universidade Estadual Paulista; 14884-900 Jaboticabal São Paulo Brazil
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29
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Waqas MY, Lisi H, Yang P, Ullah S, Zhang L, Zhang Q, Li Q, Ahmad N, Chen W, Zeshan B, Chen Q. Novel cellular evidence of oviduct secretions in the Chinese soft-shelled turtle Pelodiscus sinensis. ACTA ACUST UNITED AC 2015; 323:655-65. [PMID: 26350585 DOI: 10.1002/jez.1957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 07/09/2015] [Accepted: 07/13/2015] [Indexed: 01/09/2023]
Abstract
The oviduct is the location of fertilization and sperm storage. We examined the ultrastructure of the oviduct epithelium and its glandular secretions in the isthmus, uterus and vagina of Chinese soft-shelled turtle Pelodiscus sinensis using light and transmission electron microscopy. The epithelium in these segments is lined with ciliated, secretory and other cells; the first two cell types span the entire epithelium, with secretory cells being predominant. The ciliated cells are characterized by the presence of a secretory vacuole that releases apocrine secretions into the lumen, whereas the secretory cells contain typical biphasic granules with both dark and light aspects. The third type of cells observed have wider proximal portion, abundant mitochondria, vacuoles, and narrow nuclei. The storage of spermatozoa is restricted to the isthmus, uterus, and vagina. In addition, the gland cells show prominent features, including the presence of granules of different shapes, sizes, and electron densities. The synthesis of these granules is described for the first time in this study. Mitochondria appear to play an important role in the formation of dense granules, the rough endoplasmic reticulum and microfilaments may also play a role in the maturation of these dense granules. After completing the maturation process, these granules are released into the lumen of the gland cells.
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Affiliation(s)
- Muhammad Yasir Waqas
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Hu Lisi
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Ping Yang
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Shakeeb Ullah
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Linli Zhang
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Qian Zhang
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Quanfu Li
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Nisar Ahmad
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Wei Chen
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
| | - Basit Zeshan
- Molecular Biology Laboratory, Faculty of Veterinary Medicine, University Malaysia Kelantan, Malaysia
| | - Qiusheng Chen
- Key Laboratory of Animal Physiology and Biochemistry, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China
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30
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Leite GB, Franco-Belussi L, Provete DB, de Oliveira C. Comparative testis morphology of Neotropical anurans. ZOOL ANZ 2015. [DOI: 10.1016/j.jcz.2015.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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