1
|
Doody JS, Shukla S, Hasiotis ST. Why animals construct helical burrows: Construction vs. post-construction benefits. Ecol Evol 2024; 14:e11181. [PMID: 39263461 PMCID: PMC11387725 DOI: 10.1002/ece3.11181] [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: 04/16/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 09/13/2024] Open
Abstract
The extended phenotype of helical burrowing behavior in animals has evolved independently many times since the Cambrian explosion (~540 million years ago [MYA]). A number of hypotheses have been proposed to explain the evolution of helical burrowing in certain taxa, but no study has searched for a general explanation encompassing all taxa. We reviewed helical burrowing in both extant and extinct animals and from the trace fossil record and compiled 10 hypotheses for why animals construct helical burrows, including our own ideas. Of these, six are post-construction hypotheses-benefits to the creator or offspring, realized after burrow construction-and four are construction hypotheses reflecting direct benefits to the creator during construction. We examine the fit of these hypotheses to a total of 21 extant taxa and ichnotaxa representing 59-184 possible species. Only two hypotheses, antipredator and biomechanical advantage, cannot be rejected for any species (possible in 100% of taxa), but six of the hypotheses cannot be rejected for most species (possible in 86%-100% of taxa): microclimate buffer, reduced falling sediment (soil), anticrowding, and vertical patch. Four of these six are construction hypotheses, raising the possibility that helical burrowing may have evolved without providing post-construction benefits. Our analysis shows that increased drainage, deposit feeding, microbial farming, and offspring escape cannot explain helical burrowing behavior in the majority of taxa (5%-48%). Overall, the evidence does not support a general explanation for the evolution of helical burrowing in animals. The function and evolution of the helix as an extended phenotype seems to provide different advantages for different taxa in different environments under different physicochemical controls (some traces/tracemakers are discussed in more detail due to their association with body fossils and well-constrained physicochemical parameters). Although direct tests of many of the hypotheses would be difficult, we nevertheless offer ways to test some of the hypotheses for selected taxa.
Collapse
Affiliation(s)
- J Sean Doody
- Department of Integrative Biology University of South Florida St. Petersburg Florida USA
| | - Shivam Shukla
- Department of Integrative Biology University of South Florida St. Petersburg Florida USA
| | | |
Collapse
|
2
|
Wang W, Liu GM, Zhang DX. Intraspecific variation in metabolic rate and its correlation with local environment in the Chinese scorpion Mesobuthus martensii. Biol Open 2019; 8:bio.041533. [PMID: 31164338 PMCID: PMC6602336 DOI: 10.1242/bio.041533] [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] [Indexed: 12/16/2022] Open
Abstract
Scorpions are well known for their reduced resting metabolic rate (RMR) in comparison to typical arthropods. Since RMR is a key physiological trait linked with evolutionary fitness, it is expected that there may exist intraspecific RMR variation given the ecological and geographical heterogeneities across the distributional range of a species. Nevertheless, it is unclear whether RMR variation exists among scorpion populations. Here, we compared the RMR (VCO2) of 21 populations of the Chinese scorpion Mesobuthus martensii (Scorpiones: Buthidae) at 25°C after at least 3 months of laboratory acclimation. The following results were obtained. First, there was significant difference in RMR between sexes when body-weight effects were factored out. Second, significant local variation in RMR was detected by analyses of both variance and covariance, with one population showing significantly reduced RMR and another significantly increased RMR. Third, regression analysis indicated that the local mean temperature and mean annual days of rainfall were the two significant factors associated with the aforementioned inter-population difference in RMR. The implication of such an association was discussed. Summary: Metabolic rate variation is observed between the two sexes and among populations in the Chinese scorpion, with the latter being correlated negatively with local mean temperature and positively with annual days of rainfall.
Collapse
Affiliation(s)
- Wei Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Gao-Ming Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing 100101, China.,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - De-Xing Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Beijing 100101, China .,University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.,Beijing Institute of Genomics, Chinese Academy of Sciences, 1 Beichen West Road, Beijing 100101, China
| |
Collapse
|
3
|
Pimenta RJG, Brandão-Dias PFP, Leal HG, do Carmo AO, de Oliveira-Mendes BBR, Chávez-Olórtegui C, Kalapothakis E. Selected to survive and kill: Tityus serrulatus, the Brazilian yellow scorpion. PLoS One 2019; 14:e0214075. [PMID: 30943232 PMCID: PMC6447240 DOI: 10.1371/journal.pone.0214075] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 03/06/2019] [Indexed: 12/04/2022] Open
Abstract
Annually, more than 1.2 million scorpion stings and more than 3,000 deaths occur worldwide. Tityus serrulatus Lutz and Mello, 1922 (Scorpiones, Buthidae) is the most medically relevant species in Brazil where it is spreading rapidly and causing over 90,000 cases of envenomation yearly. We monitored T. serrulatus longevity and ability to reproduce under conditions of food and/or water deprivation. We found that T. serrulatus is highly tolerant to food deprivation, with individuals enduring up to 400 days without food. On the other hand, access to water played a pivotal role in T. serrulatus survival. Food and water deprived scorpions showed weight reduction. Reproduction occurred throughout the year for food-deprived scorpions and controls, but not in the water-deprived groups. Remarkably, food-deprived animals were able to give birth after 209 days of starvation. Tityus serrulatus resistance to food and water deprivation is likely to be an additional factor underlying this species' geographic expansion and the difficulties encountered in controlling it.
Collapse
Affiliation(s)
- Ricardo José Gonzaga Pimenta
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Pedro Ferreira Pinto Brandão-Dias
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Hortênsia Gomes Leal
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Anderson Oliveira do Carmo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Carlos Chávez-Olórtegui
- Departamento de Bioquímica-Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Evanguedes Kalapothakis
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
| |
Collapse
|
4
|
Adams AM, Marais E, Turner JS, Prendini L, Pinshow B. Similar burrow architecture of three arid-zone scorpion species implies similar ecological function. Naturwissenschaften 2016; 103:56. [PMID: 27312362 DOI: 10.1007/s00114-016-1374-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 05/16/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
Many animals reside in burrows that may serve as refuges from predators and adverse environmental conditions. Burrow design varies widely among and within taxa, and these structures are adaptive, fulfilling physiological (and other) functions. We examined the burrow architecture of three scorpion species of the family Scorpionidae: Scorpio palmatus from the Negev desert, Israel; Opistophthalmus setifrons, from the Central Highlands, Namibia; and Opistophthalmus wahlbergii from the Kalahari desert, Namibia. We hypothesized that burrow structure maintains temperature and soil moisture conditions optimal for the behavior and physiology of the scorpion. Casts of burrows, poured in situ with molten aluminum, were scanned in 3D to quantify burrow structure. Three architectural features were common to the burrows of all species: (1) a horizontal platform near the ground surface, long enough to accommodate the scorpion, located just below the entrance, 2-5 cm under the surface, which may provide a safe place where the scorpion can monitor the presence of potential prey, predators, and mates and where the scorpion warms up before foraging; (2) at least two bends that might deter incursion by predators and may reduce convective ventilation, thereby maintaining relatively high humidity and low temperature; and (3) an enlarged terminal chamber to a depth at which temperatures are almost constant (±2-4 °C). These common features among the burrows of three different species suggest that they are important for regulating the physical environment of their inhabitants and that burrows are part of scorpions' "extended physiology" (sensu Turner, Physiol Biochem Zool 74:798-822, 2000).
Collapse
Affiliation(s)
- Amanda M Adams
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel. .,Department of Biology, Texas A&M University, College Station, TX, 77843, USA.
| | - Eugene Marais
- Department of Entomology, National Museum of Namibia, Windhoek, Namibia
| | - J Scott Turner
- Department of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, New York, NY, 13210, USA
| | - Lorenzo Prendini
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, 10024, USA
| | - Berry Pinshow
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel
| |
Collapse
|
5
|
Scorpion speciation in the Holy Land: Multilocus phylogeography corroborates diagnostic differences in morphology and burrowing behavior among Scorpio subspecies and justifies recognition as phylogenetic, ecological and biological species. Mol Phylogenet Evol 2015; 91:226-37. [DOI: 10.1016/j.ympev.2015.04.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 04/28/2015] [Accepted: 04/28/2015] [Indexed: 11/21/2022]
|
6
|
Aggarwal DD, Ranga P, Kalra B, Parkash R, Rashkovetsky E, Bantis LE. Rapid effects of humidity acclimation on stress resistance in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2013; 166:81-90. [PMID: 23688505 DOI: 10.1016/j.cbpa.2013.05.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 05/12/2013] [Accepted: 05/13/2013] [Indexed: 01/27/2023]
Abstract
We tested the hypothesis whether developmental acclimation at ecologically relevant humidity regimes (40% and 75% RH) affects desiccation resistance of pre-adults (3rd instar larvae) and adults of Drosophila melanogaster Meigen (Diptera: Drosophilidae). Additionally, we untangled whether drought (40% RH) acclimation affects cold-tolerance in the adults of D. melanogaster. We observed that low humidity (40% RH) acclimated individuals survived significantly longer (1.6-fold) under lethal levels of desiccation stress (0-5% RH) than their counter-replicates acclimated at 75% RH. In contrast to a faster duration of development of 1st and 2nd instar larvae, 3rd instar larvae showed a delayed development at 40% RH as compared to their counterparts grown at 75% RH. Rearing to low humidity conferred an increase in bulk water, hemolymph content and dehydration tolerance, consistent with increase in desiccation resistance for replicates grown at 40% as compared to their counterparts at 75% RH. Further, we found a trade-off between the levels of carbohydrates and body lipid reserves at 40% and 75% RH. Higher levels of carbohydrates sustained longer survival under desiccation stress for individuals developed at 40% RH than their congeners at 75% RH. However, the rate of carbohydrate utilization did not differ between the individuals reared at these contrasting humidity regimes. Interestingly, our results of accelerated failure time (AFT) models showed substantial decreased death rates at a series of low temperatures (0, -2, or -4°C) for replicates acclimated at 40% RH as compared to their counter-parts at 75% RH. Therefore, our findings indicate that development to low humidity conditions constrained on multiple physiological mechanisms of water-balance, and conferred cross-tolerance towards desiccation and cold stress in D. melanogaster. Finally, we suggest that the ability of generalist Drosophila species to tolerate fluctuations in humidity might aid in their existence and abundance under expected changes in moisture level in course of global climate change.
Collapse
|
7
|
Kalra B, Gefen E. Scorpions regulate their energy metabolism towards increased carbohydrate oxidation in response to dehydration. Comp Biochem Physiol A Mol Integr Physiol 2012; 162:372-7. [DOI: 10.1016/j.cbpa.2012.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2012] [Revised: 04/09/2012] [Accepted: 04/10/2012] [Indexed: 11/29/2022]
|
8
|
Johnson RA, Kaiser A, Quinlan M, Sharp W. Effect of cuticular abrasion and recovery on water loss rates in queens of the desert harvester ant Messor pergandei. ACTA ACUST UNITED AC 2012; 214:3495-506. [PMID: 21957113 DOI: 10.1242/jeb.054304] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Factors that affect water loss rates (WLRs) are poorly known for organisms in natural habitats. Seed-harvester ant queens provide an ideal system for examining such factors because WLRs for mated queens excavated from their incipient nests are twofold to threefold higher than those of alate queens. Indirect data suggest that this increase results from soil particles abrading the cuticle during nest excavation. This study provides direct support for the cuticle abrasion hypothesis by measuring total mass-specific WLRs, cuticular abrasion, cuticular transpiration, respiratory water loss and metabolic rate for queens of the ant Messor pergandei at three stages: unmated alate queens, newly mated dealate queens (undug foundresses) and mated queens excavated from their incipient nest (dug foundresses); in addition we examined these processes in artificially abraded alate queens. Alate queens had low WLRs and low levels of cuticle abrasion, whereas dug foundresses had high WLRs and high levels of cuticle abrasion. Total WLR and cuticular transpiration were lowest for alate queens, intermediate for undug foundresses and highest for dug foundresses. Respiratory water loss contributed ~10% of the total WLR and was lower for alate queens and undug foundresses than for dug foundresses. Metabolic rate did not vary across stages. Total WLR and cuticular transpiration of artificially abraded alate queens increased, whereas respiratory water loss and metabolic rate were unaffected. Overall, increased cuticular transpiration accounted for essentially all the increased total water loss in undug and dug foundresses and artificially abraded queens. Artificially abraded queens and dug foundresses showed partial recovery after 14 days.
Collapse
Affiliation(s)
- Robert A Johnson
- School of Life Sciences, Arizona State University, Tempe, AZ 85282-4501, USA.
| | | | | | | |
Collapse
|
9
|
Miyashita M, Matsushita K, Nakamura S, Akahane S, Nakagawa Y, Miyagawa H. LC/MS/MS identification of 20-hydroxyecdysone in a scorpion (Liocheles australasiae) and its binding affinity to in vitro-translated molting hormone receptors. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2011; 41:932-937. [PMID: 21958716 DOI: 10.1016/j.ibmb.2011.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/13/2011] [Accepted: 09/13/2011] [Indexed: 05/31/2023]
Abstract
Recent advances in mass spectrometry (MS) technology have facilitated the detection and quantification of minor components in organisms and the environment. In this study, we successfully identified 20-hydroxyecdysone (20E) in first instar nymphs (7 days after hatching) of the scorpion Liocheles australasiae, using tandem mass spectrometry combined with high-performance liquid chromatography (LC/MS/MS). This substance was not found in adults after the fifth stage. Other possible molting hormone candidates such as makisterone A (MaA) and ponasterone A (PoA), both of which are reported to be the molting hormones of a few arthropod species, were not detected in this scorpion. The ligand-receptor binding of 20E and its analogs was quantitatively evaluated against the in vitro-translated molting hormone receptor, the heterodimer of ecdysone receptor (EcR) and the retinoid X receptor (RXR) of L. australasiae (LaEcR/LaRXR). The concentrations of ecdysone (E), MaA, 20E, and PoA that are required to inhibit 50% of [(3)H]PoA binding to the LaEcR/LaRXR complex were determined to be 1.9, 0.69, 0.05, and 0.017 μM, respectively. The activity profiles of these 4 ecdysteroids are consistent with those obtained for the molting hormone receptors of several insects. The binding of a non-steroidal E agonist, tebufenozide, to EcR was not observed even at high concentrations, indicating that the structure of the ligand-binding pocket of LaEcR is not favorable for interaction with tebufenozide.
Collapse
Affiliation(s)
- Masahiro Miyashita
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | | | | | | | | | | |
Collapse
|
10
|
Gefen E. The Relative Importance of Respiratory Water Loss in Scorpions Is Correlated with Species Habitat Type and Activity Pattern. Physiol Biochem Zool 2011; 84:68-76. [DOI: 10.1086/657688] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
11
|
Gefen E, Ung C, Gibbs AG. Partitioning of transpiratory water loss of the desert scorpion, Hadrurus arizonensis (Iuridae). JOURNAL OF INSECT PHYSIOLOGY 2009; 55:544-548. [PMID: 19232406 DOI: 10.1016/j.jinsphys.2009.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 01/25/2009] [Accepted: 01/26/2009] [Indexed: 05/27/2023]
Abstract
Terrestrial arthropods lose body water to the environment mainly through transpiration. The aim of this study was to determine the fraction of respiratory losses from total transpiratory water loss in scorpions, as relatively high respiratory losses would indicate a fitness benefit from regulation of gas-exchange rate under stressful desiccating conditions. We measured metabolic rates and water-loss rates of Hadrurus arizonensis (Iuridae) at a range of ecologically-relevant temperatures. Calculation of respiratory water losses was based on increased metabolic and water-loss rates during nocturnal activity (assuming no change in cuticular resistance at a given constant experimental temperature). Respiratory losses accounted for 9.0+/-1.7% of total transpiratory losses at 25 degrees C, doubled to 17.9+/-1.8% at 30 degrees C and increased to 31.0+/-2.0% at 35 degrees C (n=5, 15 and 15, respectively). Furthermore, the relative importance of respiratory transpiration is likely to be higher at temperatures above 35 degrees C, which have been recorded even within the burrows of H. arizonensis. Measurements of cuticular lipid melting points do not provide evidence for increased cuticular resistance to water loss at higher temperatures. However, the relatively high fraction of respiratory water losses reported here for H. arizonensis supports the notion of respiratory regulation as an evolved mechanism for conserving scorpion body water stores under stressful conditions.
Collapse
Affiliation(s)
- Eran Gefen
- School of Life Sciences, University of Nevada, Las Vegas, NV 89154-4004, USA.
| | | | | |
Collapse
|
12
|
|
13
|
Gefen E. Sexual dimorphism in desiccation responses of the sand scorpion Smeringurus mesaensis (Vaejovidae). JOURNAL OF INSECT PHYSIOLOGY 2008; 54:798-805. [PMID: 18374353 DOI: 10.1016/j.jinsphys.2008.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2007] [Revised: 02/07/2008] [Accepted: 02/08/2008] [Indexed: 05/26/2023]
Abstract
The osmoregulatory and respiratory responses of male and female Smeringurus mesaensis (Vaejovidae) to prolonged desiccation were measured. No significant effect of sex on mass-loss rates (MLRs) was found. Still, females maintained their haemolymph osmolality when desiccated to 10% mass loss, whereas that of males increased significantly after loss of as little as 5% of initial mass. Females had a 3-fold larger hepatopancreas, significantly higher hepatopancreas water content and higher metabolic rates when adjusted to hepatopancreas-free dry mass. Thus, females not only store more water in the hepatopancreas but also mobilise it to the haemolymph at a higher rate during desiccation, thus maintaining haemolymph osmolality. Gas exchange rates of both males and females decrease as desiccation progresses. An initial respiratory exchange ratio (RER) of approximately 0.9 is followed by a significant increase at mass loss levels of 7.5% and higher. RER values greater than 1.0 may result from partial shift to anaerobic catabolism, which allows closure of the book lung spiracles for longer duration, thus minimising respiratory water loss. The effects of gas exchange rates on rates of water mobilisation between body compartments and water loss to the environment suggest a trade-off between maintaining osmotic stability and conserving body water stores under stressful conditions.
Collapse
Affiliation(s)
- Eran Gefen
- School of Life Sciences, University of Nevada, 4505 Maryland Parkway, Las Vegas, NV 89154-4004, USA.
| |
Collapse
|
14
|
Gefen E, Ar A. Temperature dependence of water loss rates in scorpions and its effect on the distribution of Buthotus judaicus (Buthidae) in Israel. Comp Biochem Physiol A Mol Integr Physiol 2006; 144:58-62. [PMID: 16600648 DOI: 10.1016/j.cbpa.2006.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 02/02/2006] [Accepted: 02/08/2006] [Indexed: 11/22/2022]
Abstract
Scorpions of the family Buthidae have been shown to be more desiccation resistant in comparison with sympatric Scorpionidae species. This has been attributed to the surface-dwelling existence of the former, which unlike most other scorpion species do not avoid environmental extremes by burrowing. Still, within Buthidae, the mesic Buthotus judaicus showed better osmoregulatory capacities than the xeric Leiurus quinquestriatus, largely as a result of its high resistance to water loss. However, B. judaicus exhibited poor ability to regulate its haemolymph osmolarity at 37 degrees C. In this study we report a sharp increase in water loss rates of B. judaicus at the 30-35 degrees C temperature range compared to that measured for L. quinquestriatus, which could explain the poor osmoregulatory performance of the former at higher ambient temperatures. The increase in water loss rates of B. judaicus at high temperatures is not coupled with a similar increase in respiratory rate, suggesting an increase in cuticular permeability. We suggest that this increase in cuticular permeability, which may result from a relatively low critical transition temperature, contributes to limiting the distribution of B. judaicus to habitats of moderate environmental conditions.
Collapse
Affiliation(s)
- Eran Gefen
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
| | | |
Collapse
|
15
|
Gefen E, Ar A. The effect of desiccation on water management and compartmentalisation in scorpions: the hepatopancreas as a water reservoir. J Exp Biol 2005; 208:1887-94. [PMID: 15879069 DOI: 10.1242/jeb.01568] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYScorpions of the Family Buthidae have lower water loss rates (WLR) and enhanced osmoregulatory capacities in comparison with sympatric species of F. Scorpionidae. In this study we followed changes in water content of different body compartments in four scorpion species under prolonged desiccation conditions. The high initial WLR previously reported for Scorpionidae result in rapid depletion of body water stores. A significant decrease in total body water content of Scorpionidae was recorded following loss of only 5% of initial mass, whereas no such decrease was recorded for Buthidae following severe desiccation. When desiccated, scorpions lose water primarily from the hepatopancreas, while haemolymph volume is more tightly regulated. However,the haemolymph volume of Scorpionidae decreases as a result of depletion of hepatopancreas water stores following severe desiccation. The increasing lipid fraction in the hepatopancreas of Scorpionidae during desiccation suggests that depletion of body water stores may induce enhanced catabolism of carbohydrates, which may contribute to volume regulation by making initially glycogen-bound water available to the desiccating scorpion.
Collapse
Affiliation(s)
- Eran Gefen
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
| | | |
Collapse
|