African Journal of Herpetology - latest Issue
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Volume 65, Issue 1, 2016
Sexual dimorphism in morphological traits and scaling relationships in two populations of Gallotia stehlini (Fam. Lacertidae: Squamata) from Gran CanariaSource: African Journal of Herpetology 65, pp 1 –20 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2015.1130755More Less
Lizards of the genus Gallotia, endemic to the Canary Islands, show morphological and colouration varieties that are related to within island variation in orographic and climatic characteristics. This study examines sexual size dimorphism (SSD) within and between population variation in morphological traits, and scaling relationships in G. sthelini from a southwestern locality (Tasartico) and from another (Gáldar) in the northwest of Gran Canaria. Both sites differ in climate and vegetation traits, and we hypothesised that SSD should be manifested by males having relatively larger body traits than females and that hind limb lengths should be relatively larger in individuals from the more open habitat. Results showed that one-third of the largest lizards from both populations did not differ significantly either in snout-to-vent length (SVL) nor in trunk length (TRL), but overall males had significantly larger SVL and TRL than females. Multivariate analysis showed that head width (HW) and hind limb length (HLL) were significantly larger in individuals from Tasartico than in those of Gáldar. Hind limb length was the trait that contributed most to differentiate between populations and head parameters between males and females. In both populations head and body traits scaled to TRL, head width (HW) and head depth (HD) of males having a positive allometry, and fore limb length (FLL) and hind limb length (HLL) a negative one. In relation to head length (HL), females had significantly larger TRL and smaller head depths than males; lizards from Gáldar had significantly larger trunk length (TRL), but smaller HW and HLL than those of Tasartico. We outline the multiple factors that could affect the evolution of morphometric traits of each sex, taking into account the ecological features of the two zones.
Clutch, egg and hatchling characteristics in the Souss Valley tortoises, Testudo graeca soussensis Pieh, 2001 (Testudines: Testudinidae) from an arid steppe-land of west-central MoroccoSource: African Journal of Herpetology 65, pp 21 –32 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2015.1136701More Less
Clutch, egg and hatchling characteristics in the Souss Valley tortoises Testudo graeca soussensis (Testudinidae) from an arid steppe area of west-central Morocco were investigated in semi captivity in spring-early summer 2011. Mating activity occurs twice in the year, mainly in early spring and for a short period in mid-autumn. The egg laying period lasts from late May to early July. The mean clutch size, based on the first clutches, is 3.44±1.33 eggs per clutch (range: 1-5 eggs); the eggs are elongated in shape. The mean relative egg mass and relative clutch mass are 1.70±0.28% and 4.06±1.32%, respectively. No egg variable was significantly correlated with the female body size (carapace length and body weight). The mean incubation duration of artificially incubated eggs (at 31°C) is 70±5.7 days. The body mass at hatching is 12.8±0.6 g. The carapace is sub-circular and more domed than that of adults. The obtained data are compared to those reported for other populations and subspecies of T. graeca across its distribution range. The present study would, hopefully, help to assess the potential for tortoise captive breeding in the eco-climatic conditions of Marrakech, west-central Morocco, for the reinforcement of local declining populations.
On the taxonomic status of two enigmatic southern African fossorial skinks, Scelotes bicolor and S. schebeni : short communicationAuthor Aaron M. BauerSource: African Journal of Herpetology 65, pp 33 –38 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2016.1138149More Less
The nominal taxa Scelotes bicolor and Scelotes schebeni are known only from their respective type specimens, both now lost, and they have been regarded as species inquirendae. A review of available data confirms that earlier synonymisations with S. arenicola and Melanoseps occidentalis, respectively, are correct and that the type localities of both are in error.
Vestigial appendicular skeletons in the African and Malagasy skink species Feylinia grandisquamis, Melanoseps ater, Grandidierina lineata and Voeltzkowia mira : short communicationSource: African Journal of Herpetology 65, pp 39 –46 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2015.1133722More Less
Vestigial appendicular skeletons are present but have not previously been described and illustrated in the skink species Feylinia grandisquamis and Melanoseps ater. Vestigial appendicular skeletons have been described and illustrated in only one specimen of Grandidierina lineata and in a small sample of Voeltzkowia mira. Here we report a radiographic study of the appendicular skeletons of these four species. The pectoral girdle includes a vestigial clavicle in F. grandisquamis; a vestigial scapulocoracoid and sternum in M. ater; a vestigial scapulocoracoid, interclavicle and sternum, with or without a clavicle, in G. lineata; and a clavicle and scapulocoracoid in one specimen of V. mira. In all four species the pelvic girdle includes an ilium and a puboischium. No midline contact is present between the left and right puboischium, and visible forking into a distinct pubis and ischium is present only in V. mira. The only discernible limb vestiges are humeri in V. mira.
Wide variation in carapacial scute patterns in a natural population of speckled tortoises, Homopus signatusAuthor Victor J.T. LoehrSource: African Journal of Herpetology 65, pp 47 –54 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2016.1146168More Less
The arrangement of scutes on the carapaces of extant chelonians is very similar among species, but intraspecific deviations from typical scute patterns are common. Because intraspecific variation may relate to inbreeding depression, unfavourable egg incubation conditions and the presence of environmental pollutants, investigations of carapacial scute patterns in natural populations can enhance insight into the ecologies and survival challenges of chelonians. A population of the tortoise Homopus signatus, inhabiting an arid range with substantial annual rainfall variation, was sampled to record carapacial scute patterns. The typical pattern of H. signatus consisted of five vertebral scutes, four pairs of costal scutes, a cervical and a supracaudal scute, and 12 pairs of marginal scutes. Although it was expected that size classes (i.e. representing tortoises born in different years) and sexes would have different percentages deviations from the typical scute pattern as a result of different egg incubation conditions, percentages were similar among size classes and sexes. A high percentage of 44% (25% if counts of the relatively variable marginal scutes were excluded) of all tortoises had deviant carapacial scute patterns. Since the study population was situated in a relatively pristine area and supernumerary carapacial scutes appear related to egg incubation conditions in other chelonians, the wide variation in carapacial scute patterns in wild H. signatus may be the result of frequently challenging incubation conditions in the species' harsh environment.
Factors determining the occurrence of Pleurodeles poireti (Caudata: Salamandridae) on Edough Peninsula, northeastern AlgeriaSource: African Journal of Herpetology 65, pp 55 –67 (2016) http://dx.doi.org/http://dx.doi.org/10.1080/21564574.2016.1167783More Less
Pleurodeles poireti is one of the lesser-known amphibians in the Mediterranean region. This species is strictly endemic to the Edough Peninsula in northeastern Algeria. Here we investigated the factors that determine the presence of P. poireti, by affecting its selection of both aquatic and terrestrial habitats. Aquatic habitats were characterised according to their morphology and the physicochemical parameters of the water. We also examined the topographical and substrate features, plant cover and climatic conditions at the occurrence sites. Our surveys indicated that P. poireti is widely-distributed on the Edough Peninsula. Pleurodeles poireti predominantly breeds in moderate to large water bodies densely covered with emergent vegetation. The water parameters are less influential in its selection of breeding sites, except dissolved oxygen and turbidity, which are usually high at the occupied sites. At the broad spatial scale, P. poireti is positively associated with lowlands in cultivated landscapes. However, the species has a relatively broad niche in the region, and also occurs in cork oak forests. The species tolerates some level of human alteration of the landscape, but some populations close to villages could disappear in response to the combined effects of habitat destruction and the presence of alien fish.