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Ancillotto L, Vignoli L, Martino J, Paoletti C, Romano A, Bruni G. Sexual dichromatism and throat display in spectacled salamanders: a role in visual communication? J Zool (1987) 2022. [DOI: 10.1111/jzo.13006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. Ancillotto
- Wildlife Research Unit, Dipartimento di Agraria Università degli Studi di Napoli Federico II Portici Italy
| | - L. Vignoli
- Dipartimento di Scienze Università degli studi Roma Tre Rome Italy
| | | | - C. Paoletti
- Centre Hospitalier Vétérinaire ADVETIA Exotic Animal Service Vélizy‐Villacoublay France
| | - A. Romano
- Consiglio Nazionale delle Ricerche‐ Istituto per la BioEconomia Rome Italy
| | - G. Bruni
- Viale Palmiro Togliatti 101 Sesto Fiorentino Italy
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Sexual Dimorphism in the Chinese Endemic Species Hynobius maoershanensis (Urodela: Hynobiidae). Animals (Basel) 2022; 12:ani12131712. [PMID: 35804611 PMCID: PMC9265018 DOI: 10.3390/ani12131712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 11/21/2022] Open
Abstract
Simple Summary In the present study, we examined the sexual dimorphism of Hynobius maoershanensis. The results showed that it exhibits sexual shape dimorphism, with five morphological traits being male-biased and one being female-biased. The observed sexual shape dimorphism between males and females could be explained using the sexual selection and fecundity theory hypotheses. Abstract Sexual dimorphism is common in most vertebrate species and has diverse manifestations. The study of sexual dimorphism has critical significance for evolutionary biological and ecological adaptation. In this study, we analysed the morphometric data of Hynobius maoershanensis, a rare and endangered species, to examine sexual dimorphism in size and shape. A total of 61 H. maoershanensis individuals (9 adult females and 52 adult males) were used in this study. We measured 14 morphological variables and weight of each individual. Analysis of covariance using snout–vent length (SVL) as the covariate showed significant differences in head width (HW), tail length (TL), tail height (TH), forelimb length (FLL), hindlimb length (HLL) and space between axilla and groin (AGS) between the male and female. The female AGS was greater than that of the male, whereas males had greater HW, TL, TH, FLL and HLL than females. The findings show that sexual dimorphism is present in terms of shape but not in terms of size. The wider head of the male could improve mating success, and its thicker limbs and longer tail might facilitate courtship. The females’ wider AGS may increase reproductive output. Our results support sexual dimorphism in H. maoershanensis, which could be explained by the sexual selection and fecundity theory hypothesis.
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Salamander braincase morphology as revealed by micro‐computed tomography. J Morphol 2022; 283:462-501. [DOI: 10.1002/jmor.21454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 11/07/2022]
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Staub NL. The Evolution of Derived Monomorphism From Sexual Dimorphism: A Case Study on Salamanders. Integr Org Biol 2020; 3:obaa044. [PMID: 33791587 PMCID: PMC7885154 DOI: 10.1093/iob/obaa044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
While sexual dimorphism has long received special attention from biologists, derived monomorphism, the condition in which both males and females express similar derived features has been less well studied. Historically, the appearance of "male-like" features in females has been explained by the genetic correlation between the sexes. Recent work emphasizes the importance of studying the independent selective forces on both females and males to understand sexual dimorphism. Sexual dimorphism and derived monomorphism in the genus Aneides are examined in light of predictions of social selection. Aneides hardii shows the greatest degree of sexual dimorphism in snout-vent length and head width, with the other species of Aneides less sexually dimorphic. This reduced dimorphism, however, is not a return to an ancestral monomorphic state, but rather exemplifies derived monomorphism because females express traits that were limited in expression to males of ancestral species. Instead of calling these "male-typical" traits in females, I suggest the term "derived monomorphic" traits as these traits are typical in these females, and "derived monomorphic" can apply to both sexes. Increased attention to studying the patterns and ecological significance of derived monomorphism will shed light on the underlying selective forces, including sexual selection, on both females and males.
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Affiliation(s)
- Nancy L Staub
- Department of Integrative Biology, Museum of Vertebrate Zoology, University of California at Berkeley, Berkeley, CA 94720, USA
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Macaluso L, Villa A, Pitruzzella G, Rook L, Pogoda P, Kupfer A, Delfino M. Osteology of the Italian endemic spectacled salamanders, Salamandrina spp. (Amphibia, Urodela, Salamandridae): selected skeletal elements for palaeontological investigations. J Morphol 2020; 281:1391-1410. [PMID: 32881082 DOI: 10.1002/jmor.21254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/29/2020] [Accepted: 08/02/2020] [Indexed: 11/08/2022]
Abstract
Salamandrina perspicillata, from Northern and Central Italy, and Salamandrina terdigitata, from Southern Italy, represent a unique case of endemism among the amphibians of Europe. Some efforts were made to study the biology and ecology of these species, but only few studies focused on their comparative osteology. In particular, detailed descriptions of isolated skeletal elements and comparisons with other European urodeles are not available in literature hindering the identification of their fossils that testify for an ancient much broader range. The correct identification of fossil remains, mostly based on careful osteological descriptions, is fundamental to study the evolution of the range of this genus through time and the origin of the current endemic condition. This work is focused on the description of selected skeletal elements (occipito-otic complex, limb bones, atlas, trunk, sacral, caudosacral and caudal vertebrae) of dry-prepared skeletons and CT-scans of wet preserved specimens, which are the most common in the fossil record. We provide osteological comparison of Salamandrina with other genera of Europe, yielding diagnostic characters which allow the identification of fossils at a generic level. No significant differences between the two species S. perspicillata and S. terdigitata were found in the described skeletal elements, thus, the identification of skeletal elements at the species level is, at the moment, impossible.
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Affiliation(s)
- Loredana Macaluso
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Torino, Italy
| | - Andrea Villa
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Torino, Italy.,Staatliche Naturwissenschaftliche Sammlungen Bayerns - Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany
| | - Gaetano Pitruzzella
- Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Firenze, Italy
| | - Lorenzo Rook
- Dipartimento di Scienze della Terra, Università degli Studi di Firenze, Firenze, Italy
| | - Peter Pogoda
- Department of Zoology, State Museum of Natural History Stuttgart, Stuttgart, Germany.,Comparative Zoology, Institute of Evolution and Ecology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Alexander Kupfer
- Department of Zoology, State Museum of Natural History Stuttgart, Stuttgart, Germany.,Institute of Zoology, University of Hohenheim, Stuttgart, Germany
| | - Massimo Delfino
- Dipartimento di Scienze della Terra, Università degli Studi di Torino, Torino, Italy.,Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona. Edifici ICTAICP, Barcelona, Spain
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Hara S, Nishikawa K. Intraspecific Variation in the External and Skeletal Morphology of Hynobius setouchi Matsui, Okawa, Tanabe et Misawa, 2019 (Amphibia: Urodela: Hynobiidae). Zoolog Sci 2020; 37:346-357. [PMID: 32729713 DOI: 10.2108/zs190155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 04/09/2020] [Indexed: 11/17/2022]
Abstract
The hynobiid salamander genus Hynobius is a basal taxon in the urodeles that plays a key role in understanding the evolution of sexual dimorphism in urodeles. We examined the age (juveniles vs. adults) and sexual differences in the external and skeletal morphology of a Japanese lentic breeding salamander, Hynobius setouchi. We found that juveniles had larger heads than those of adults, and most characters were larger in adult males than in females, except for trunk size. This was also observed in skeletal morphology, although some tail characters differed only in the skeleton. We suggest that intra- and interspecific comparisons of the external and skeletal characters of salamanders should consider age, sexual, and seasonal differences.
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Affiliation(s)
- Sotaro Hara
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan,
| | - Kanto Nishikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
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Pogoda P, Zuber M, Baumbach T, Schoch RR, Kupfer A. Cranial shape evolution of extant and fossil crocodile newts and its relation to reproduction and ecology. J Anat 2020; 237:285-300. [PMID: 32297321 PMCID: PMC7369190 DOI: 10.1111/joa.13201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/19/2020] [Accepted: 03/19/2020] [Indexed: 01/22/2023] Open
Abstract
The diversity of the vertebrate cranial shape of phylogenetically related taxa allows conclusions on ecology and life history. As pleurodeline newts (the genera Echinotriton, Pleurodeles and Tylototriton) have polymorphic reproductive modes, they are highly suitable for following cranial shape evolution in relation to reproduction and environment. We investigated interspecific differences externally and differences in the cranial shape of pleurodeline newts via two‐dimensional geometric morphometrics. Our analyses also included the closely related but extinct genus Chelotriton to better follow the evolutionary history of cranial shape. Pleurodeles was morphologically distinct in relation to other phylogenetically basal salamanders. The subgenera within Tylototriton (Tylototriton and Yaotriton) were well separated in morphospace, whereas Echinotriton resembled the subgenus Yaotriton more than Tylototriton. Oviposition site choice correlated with phylogeny and morphology. Only the mating mode, with a random distribution along the phylogenetic tree, separated crocodile newts into two morphologically distinct groups. Extinct Chelotriton likely represented several species and were morphologically and ecologically more similar to Echinotriton and Yaotriton than to Tylototriton subgenera. Our data also provide the first comprehensive morphological support for the molecular phylogeny of pleurodeline newts.
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Affiliation(s)
- Peter Pogoda
- Department of Zoology, State Museum of Natural History Stuttgart, Stuttgart, Germany.,Comparative Zoology, Institute of Evolution and Ecology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Marcus Zuber
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.,Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Tilo Baumbach
- Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.,Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Rainer R Schoch
- Department of Paleontology, State Museum of Natural History Stuttgart, Stuttgart, Germany
| | - Alexander Kupfer
- Department of Zoology, State Museum of Natural History Stuttgart, Stuttgart, Germany.,Institute of Zoology, University of Hohenheim, Stuttgart, Germany
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Xiong J, Zhang B, Liu Q, Pan T, Gou J. Sexual dimorphism in the Chinese endemic species Pachyhynobius shangchengensis Fei, Qu and Wu, 1983 (Urodela: Hynobiidae). PeerJ 2019; 7:e6408. [PMID: 30809436 PMCID: PMC6385682 DOI: 10.7717/peerj.6408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/04/2019] [Indexed: 12/27/2022] Open
Abstract
Sexual dimorphism (SD) is a widespread phenomenon in most vertebrate species and is exhibited in a myriad of ways. In amphibians, sexual size dimorphism, in which females are larger than males, is the most common type, and sexual shape dimorphism varies among species. Different selection forces (sexual selection, fecundity selection, and ecological selection) that act differently upon the sexes form the consequence of SD. Thus, studies of SD provide information about the general intersexual divergence of the same species and allow insights into the impact of selective forces on the sexes. In this study, we analyzed morphometric data of the Shangcheng stout salamander, Pachyhynobius shangchengensis, an endemic and poorly known Chinese salamander, to examine sexual dimorphism in size and shape. The morphometric data included 15 characteristics of 68 females and 55 males which were analyzed using univariate and multivariate methods. A significant difference was found between the sexes in terms of both body size (snout-vent length) and some body shapes (e.g., head length and width, tail length and width, distance between limbs, and limb length and width) in this salamander. The longer snout-vent length in males may be attributed to sexual selection, longer and wider head in males may contribute to male-male competition, longer and wider tail in males may be attributed to energy storage and reproductive success, the larger distance between limbs in females is likely due to a fecundity advantage, and longer and more robust limbs in males may be related to reproductive or competitive behaviors. These results demonstrated that sexual dimorphism of different morphological traits is the consequence of different selection forces that act differently upon the sexes.
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Affiliation(s)
- Jianli Xiong
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China
| | - Baowei Zhang
- School of life Science, Anhui University, Hefei, Anhui, China
| | - Qiangqiang Liu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China
| | - Tao Pan
- School of life Science, Anhui University, Hefei, Anhui, China
| | - Jianping Gou
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China
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