C.S Wiesner, C.Iben. 2002. Influence of environmental humidity and dietary protein on pyramidal growth of carapaces in African spurred tortoises (Geochelene sulcata)Download article, pdf file 1,5 MB (sign on required)
Akani, G.C., L. Luiselli, S.M. Wariboko, L. Ude & F.M. Angelici, 2002. Frequency of tail automy in the African Olive Grass Snake, Psammophis 'philipsii' from three habitats in southern Nigeria. Afr. J. Herpetol. 51: 135-138.
Donaire Barroso D. & S. Bogaerts. 2001. Observations on viviparity of Salamandra algira in North Morocco. pp 147-151 in Lymberakis, P., Valakos, E., Pafilis, P., and M., Mylonas (eds.). Herpetologia Candiana. S.E.H. Irakleio 2001. Published in the Proceedings of the 10th OGM of the Societas Europeae Herpetologica)We present the first data on a viviparous reproduction mode of Salamandra algira at Tangitana region of Morocco. In S. algira there are two reproductive modes: the classical ovoviviparous in most of the distribution range and a viviparous mode in the Tangitana region. The mechanism of viviparity seems to resemble that of S. s. bernardezi.
Autumn, K., Sitti, M., Liang, Y.A., Peattie, A.M., Hansen, W.R., Sponberg, S., Kenny, T.W., Fearing, R., Israelachvili, J.N. & R.J. Full (2002) Evidence for van der Waals adhesion in gecko setae. Proc. Natl. Acad. Sc. US, 99: 12252-12256.
Geckos have evolved one of the most versatile and effective adhesives known. The mechanism of dry adhesion in the millions of setae on the toes of geckos has been the focus of scientific study for over a century. We provide the first direct experimental evidence for dry adhesion of gecko setae by van der Waals forces, and reject the use of mechanisms relying on high surface polarity, including capillary adhesion. The toes of live Tokay geckos were highly hydrophobic, and adhere equally well to strongly hydrophobic and strongly hydrophyllic, polarizable surfaces. Adhesion of a single isolated gecko seta was equally effective on the hydrophobic and hydrophilic surfaces of a microelectro-mechanical systems force sensor. A van der Waals mechanism implies that the remarkable adhesive properties of gecko setae are merely a result of the size and shape of the tips, and are not strongly affected by surface chemistry. Theory predicts greater adhesive forces simply from subdividing setae to increase surface density, and suggests a possible design principle underlying the repeated, convergent evolution of dry adhesive microstructures in gecko, anoles, skinks, and insects. Estimates using a standard adhesion model and our measured forces come remarklably close to predicting the tip size of Tokay gecko seta. We verified the dependence on size and not surface type by using physical models of setal tips nanofabricated from two different materials. Both artificial setal tips stuck as predicted and provide a path to manufacturing the first dry, adhesive microstructure.
Calsbeek, R. & B. Sinervo (2002) Uncoupling direct and indirect components of female choice in the wild. Proc. Natl. Acad. Sc. US, 99: 14897-14902.
One of the most controversial debates in evolutionary biology concerns the fitness consequences of female choice in nature. Discriminating females may benefit from high-quality territories and/or sires with high-quality genes. Here we experimentally dissociate female preferences for high-quality territories and male body size in a wild population of side-blotched lizards, Uta stansburiana. Females preferred experimentally improved territories but still chose high-quality sires for their progeny. High-quality territories were associated with earlier egg-laying dates and larger eggs. These maternal effects, evidently stimulated by high-quality territories, have been shown to enhance competitive ability and therefore the likelihood that philopatric offspring will capitalize on the direct benefits of superior territories, previously shown to promote progeny growth rate and survival (most offspring do not disperse from their natal area). Paternity analysis within clutches co-sired by two males revealed that female preferences for large males were also adaptive in terms of indirect benefits. Females used sperm from large sires to produce sons and sperm from small sires to produce daughters. Differential allocation of resources and progeny sex was adaptive and demonstrates a high degree of female control in the mating system.
Genet, K.S., 2002. Structural habitat and ecological overlap of the Puerto Rican Lizards Anolis cristatellus and A. cooki, with comments on the long-term survival and conservation of A. cooki. Carr. J. Sc. 38: 272-278.
Green, B. T., Yorks, D.T., Parmer-Lee, J.S., Powell, R. & R.W. Henderson, 2002. Discovery of Anolis sagrei in Grenada with comments on its potential impact on native Anoles. Carr. J. Sc. 38: 270-272.
Ramos, C.W., Pimentel, N. & V. Martínez-Cortés, 2002. Karyotype of the Endemic Golden Frog Atelopus zeteki (Dunn) from Panama. Carr. J. Sc. 38: 268-270.
Austin, J.J. & E.N. Arnold, 2001. Ancient mitochondrial DNA and morphology elucidate an extinct island radiation of Indian Ocean giant tortoises (Cylindraspis) Proc. R. Soc. Lond. B 268, 2515-2523.>
Ancient mitochondrial DNA sequences were used for investigating the evolution of an entire clade of extinct vertebrates, the endemic tortoises (Cylindraspis) of the Mascarene Islands in the Indian Ocean. Mitochondrial DNA corroborates morphological evidence that there were five species of tortoise with the following relationships: Cylindraspis triserrata ((Cylindraspis vosmaeri and Cylindraspis peltastes) (Cylindraspis inepta and Cylindraspis indica)). Phylogeny indicates that the ancestor of the group first colonized Mauritius where speciation produced C. triserrata and the ancestor of the other species including a second sympatric Mauritian form, C. inepta. A propagule derived from this lineage colonized Rodrigues 590 km to the east, where a second within-island speciation took place producing the sympatric C. vosmaeri and C. peltastes. A recent colonization of Réunion 150 km to the southwest produced C. indica. In the virtual absence of predators, the defensive features of the shells of Mascarene tortoises were largely dismantled, apparently in two stages. `Saddlebacked’ shells with high fronts evolved independently on all three islands. This and other features, such as a derived jaw structure and small body size, may be associated with niche differentiation in sympatric species and may represent a striking example of parallel differentiation in a large terrestrial vertebrate. The history of Mascarene tortoises contrasts with that of the Galápagos, where only a single species is present and surviving populations are genetically much more similar. However, they too show some reduction in anti-predator mechanisms and multiple development of populations with saddlebacked shells.
Eaton, J.M., Larimer, S.C., Howard, K.G., Powell, R. & J.S. Parmerlee, Jr., 2002. Population d ensities and ecological release of the solitary lizard Anolis gingivinus in Anguilla, West Ind ies. Carrib. J. Sci. 38: 27-36.
The predominant natural habitat of Anguilla is an evergreen scrub forest, much of it degraded by feral goats. The island is comprised of a patchwork of variously altered habitats, almost a ll of which are occupied by Anolis gingivinus. In June 2000, we investigated the natural histo ry of this anole to identify the factors that most accurately predict population densities and to determine if ecological release has occurred due to the absence of congeneric competition. We examined population sizes and densities, structural habitat use, thermal biology, and diet . We predicted the relative number of anoles in six representative habitats based on relative abundance of perches, their diameter, and varying degrees of insolation. Structural niche use, thermal biology, and diet were very similar to or less diverse than those of morphologically similar trunk-ground ecomorphs on multi-species Greater Antillean islands, suggesting that eco logical release has not occurred.
Reinert, H.K., Bushar, L.M., Rocco, G.L., Goode, M. & R.A. Odum, 2002. Distribution of the Aru ba Island Rattlesnake, Crotalus unicolor, on Aruba, Dutch West Indies. Carrib. J. Sci. 38: 126-128.Download article, pdf file 249 KB (sign on required)
Hedges, S.B. & R. Thomas, 2001. At the lower size limit in amniote vertebrates: A new diminutive lizard from the West Indies. - Carib. J. Sci. 37: 168-173.
A new species of gekkonid lizard is described from Isla Beata and adjacent areas of Hispaniola, West Indies. Sphaerodactylus ariasae, sp. nov. is most closely related to S. streptophorus, from which it differs in size, color pattern, scalation, and snout shape. Its most distinctive feature is the very small adult body size, averaging only 16 (14-18) mm snout-to-vent-length. The new species and S. parthenopion (British Virgin Islands) are the smallest of the approximately 23,000 species of amniote vertebrates.
Feldman, C.R. & J. Ford Parham, 2002. Molecular phylogenetics of emydine turtles: Taxonomic revision and the evolution of shell kinesis. Mol. Phylogen. Evol. 22: 388-398.
The 10 extant species of emydine turtles represent an array of morphological and ecological forms recognizable and popular among scientists and hobbyists. Nevertheless, the phylogenetic affinities of most emydines remain contentious. Here, we examine the evolutionary relationships of emydine turtles using 2092 bp of DNA encoding the mitochondrial genes cyt b, ND4, and adjacent tRNAs. These data contain 339 parsimony informative characters that we use to erect hypotheses of relationships for the Emydinae. Both maximum parsimony and maximum likelihood methods yield a monophyletic Emydinae in which all but three nodes are well resolved. Emys orbicularis, Emydoidea blandingii, and Clemmys marmorata form a monophyletic clade, as do the species of Terrapene. Clemmys muhlenbergii and Clemmys insculpta form a third monophyletic group that may be sister to all other emydines. Clemmys guttata is problematic and probably related to Terrapene. Based on this phylogeny, and previous molecular work on the group, we suggest the following taxonomic revisions: (1) Clemmys should be restricted to a single species, C. guttata. (2) Calemys should be resurrected for C. muhlenbergii and C. insculpta. (3) Emys should be expanded to include three species: E. orbicularis, E. blandingii, and E. marmorata. Furthermore, our analyses show that neither kinetic-shelled nor akinetic-shelled emydines form monophyletic groups. Therefore, shell kinesis was either independently gained in Emys and Terrapene or secondarily lost in E. marmorata and C. guttata. Parsimony, paleontological evidence, and the multiple origins of shell kinesis in related turtle lineages (especially geoemydines) support the independent origin of plastral kinesis.
Holman, J.A. & U. Fritz, 2001. A new emydine species from the Middle Miocene (Barstovian) of Nebraska, USA, with a new generic arrangement for the species of Clemmys sensu McDOWELL (1964) (Reptilia: Testudines: Emydidae. Zool. Abhandlgn. (Dresden) 51: 331-353.
As there is convincing evidence for a paraphyly of the genus Clemmys sensu McDOWELL (1964), it is suggested that Clemmys RITGEN, 1828 be restricted to its type species, Clemmys guttata (SCHNEIDER, 1792). Clemmys marmorata (BAIRD & GIRARD, 1852), a species more closely related to emydine taxa with a hinged plastron than to other species with nonhinged plastra previously referred to Clemmys, is treated as a member of the monotypic genus Actinemys AGASSIZ, 1857. Clemmys insculpta (LE CONTE, 1830 (1829)) and Clemmys muhlenbergii (SCHOEPFF, 1801) are regarded as representing another distinct genus for which the name Glyptemys AGASSIZ, 1857 (species typica: Testudo insculpta LE CONTE, 1830 (1829)=Glyptemys insculpta) is given precedence over Calemys AGASSIZ, 1857, erected for Testudo muhlenbergii SCHOEPFF, 1801. - Based on a large amount of fossil material from Nebraska (USA), Glyptemys valentinensis n. sp. is described. With this new species, the genus Glyptemys is now known from the Middle Miocene (Medial to Late Barstovian: ca 14.5-11.5 Ma BP) to modern times. Glyptemys valentinensis is morphologically more similar to Glyptemys insculpta than to G. muhlenbergii. It is suggested that G. valentinensis gave rise to G. insculpta between Late Barstovian and Late Hemphillian times (11.5-5.5 Ma BP). As sequence data of the mitochondrial cytochrome b gene argue for a differentiation of G. insculpta and G. muhlenbergii exactly in Medial Barstovian times (ca 14.5 Ma BP), G. valentinensis could be the last common ancestor of G. insculpta and G. muhlenbergii.
Corrections to this paper:
1) The correct date of publication is December 10, 2001
2) It is "Middle" not "medial" in the Title.
3) A few of the fossil specimens cited from the Univ. Nebraska State Museum have field numbers rather than permanent numbers. But they are matched in the UNSM computer files and on hardcopy cards.
Mori, A. & H.J.A.R. Randriamahazo, 2002. Foraging mode of a Madagascan iguanian lizard, Oplurus cuvieri. Afr. J. Ecol. 40: 61-64.
The foraging mode of lizards has been extensively studied in members of most major families. One neglected taxon is Opluridae, a distinct Iguanian group endemic to Madagascar. We studied the foraging mode of Oplurus cuvieri cuvieri in a dry forest in north-western Madagascar. Quantitative data on the number of movements per minute arid percentage of time spent in moving indicated that O. c. cuvieri is a typical ambusher, although the lizard occasionally fed on plant materials by active foraging. Possible seasonal changes in foraging activity were suggested. The results support the previous view that insectivorous iguanian lizards are ambush foragers.