Environmental colour pattern variation in Mediterranean Podarcis.

BACKGROUND: Lizards of the genus Podarcis are widespread in the Mediterranean region, including islands and island archipelagos. These small-bodied lizards have a predominantly protective green-brown colouration. However, some populations display unusual patterns, in which the colouration is predominantly blue or uniformly black. This study explores the factors that influence this chromatic variation, whether environmental (climate and island conditions) or evolutionary (phylogenetic trait conservatism). The colouration of 1400 individuals (27 species) was analysed in the CIELAB colour space. RESULTS: Pagel's λ indicated that colouration is weakly conserved within phylogenetic lineages. Although the island surface plays a key role in the chromatic variability of these lacertids, geographic isolation and climate hold less influence. The colouration of some small island populations tends to be uniform and dark, possibly due to intense intraspecific competition and lower predatory pressure. CONCLUSIONS: This study highlights the importance of island populations in understanding the processes that favour the emergence of extreme phenotypes in small ectothermic vertebrates.

Biogeographic Inferences on the Evolutionary History of the King Cobra (Ophiophagus hannah, Cantor 1836) Species Complex.

King cobra (Ophiophagus hannah) is a snake widely distributed through southeastern tropical Asia, but in two separate subpopulations: one located in the Western Ghats (western Indian Peninsula) and the other much more extensive, ranging between the southern slopes of the Himalayas, Assam, Indochina to southeastern China. Similarly, it also appears in numerous tropical archipelagos such as Indonesia, the Philippines, and the Andaman Islands, but surprisingly it is absent from other large islands like Sri Lanka and Taiwan. In this study, we evaluated how climate could be shaping the distribution of this snake and estimated the future distribution of the species utilizing ecological niche modelling. To evaluate the effect of paleoclimatic conditions on the genetic structure of this species we performed Bayesian phylogenetic analysis under a molecular clock using mitochondrial DNA. Our analyses indicated that the current distribution of O. hannah is strongly influenced by the availability of humid climate conditions. King cobras have a long evolutionary history reflected in the appearance of four main mitochondrial lineages before the Pliocene (the Western Ghats, southeastern mainland Asia, Luzon, and Indonesia), congruently with paleoclimatic models that indicated the availability of suitable conditions for this species in these refugia during the glacial cycles. Climate history could explain the absence of O. hannah in Sri Lanka and Taiwan due to the absence of suitable climatic corridors when these islands were connected to the mainland (20,000 years ago). Future projections (2050‒2070) did not suggest significant range shifts in the region, even considering the worst global warming scenarios.

Niche diversification of Mediterranean and southwestern Asian tortoises.

Background: Tortoises of the genus Testudo are widely distributed throughout the Mediterranean region and southwestern Asia. However, the evolutionary mechanisms of diversification in this genus are still poorly understood. Methods: In this study, we assessed the evolutionary patterns in the climate niches of five species and 11 subspecies of the genus Testudo using ecological niche models and evaluated the niche overlap based on species phylogenetic distances. Results: The ecological models indicated that most species differ in their climate niches, but show overlap, with gradual transitions at range boundaries. As expected, the ecological divergence among subspecies was lower than that among species. Evaluation of the phylogenetic signal indicated that climate niches have been weakly conserved, but sister species also show high evolutionary divergence.

Vegetation cover and occurrence of salamanders in the western Mediterranean.

The Mediterranean region possesses a rich diversity of salamanders, which also exhibit a high degree of ecological diversification. It is assumed that the presence of salamanders is dependent on the level of vegetation cover in terrestrial habitats, but the strength of this association is likely to vary among species. In this study, we investigated the patterns of habitat utilization for Mediterranean salamanders based on 589 records of 33 species. We tested the hypothesis that the association between salamander presence and vegetation density varies among genera or reproductive modes (i.e. terrestrial vs aquatic). The results show that vegetation cover has similar influences on terrestrial and aquatic groups but important differences are identified for lotic and lentic aquatic species. Our findings also indicate that the aquatic lotic, terrestrial, and small-body species deviate significantly from that expected from the background range of variation.

Dispersal patterns of Squamata in the Mediterranean: An evolutionary perspective.

Mediterranean islands have a high diversity of squamates, although they are unevenly distributed. This variability in the composition of the reptile assemblages across islands may have been influenced by differences in the colonization abilities of these species. To evaluate the dispersal capacities of squamate species, we modeled their sea routes using cost surface models. We estimated the effects of some life-history traits and the phylogenetic signal in the characteristics of the modeled dispersal paths. We hypothesized that a significant phylogenetic signal should be present if the dispersal ability is enhanced by traits shared among evolutionarily related species. The results showed that no phylogenetic signal was present in the characteristics of the dispersal paths (i.e., in the distance traveled/bypassed sea depth). Thus, no superior island-colonizer lineages were detected in Mediterranean Squamata. However, our analyses also revealed that small-sized lizards were superior to other groups of squamates at dispersing over long distances on the sea.

Ship rats and island reptiles: patterns of co-existence in the Mediterranean.

BACKGROUND: The western Mediterranean archipelagos have a rich endemic fauna, which includes five species of reptiles. Most of these archipelagos were colonized since early historic times by anthropochoric fauna, such as ship rats (Rattus rattus). Here, I evaluated the influence of ship rats on the occurrence of island reptiles, including non-endemic species. METHODOLOGY: I analysed a presence-absence database encompassing 159 islands (Balearic Islands, Provence Islands, Corso-Sardinian Islands, Tuscan Archipelago, and Galite) using Bayesian-regularized logistic regression. RESULTS: The analysis indicated that ship rats do not influence the occurrence of endemic island reptiles, even on small islands. Moreover, Rattus rattus co-occurred positively with two species of non-endemic reptiles, including a nocturnal gecko, a guild considered particularly vulnerable to predation by rats. Overall, the analyses showed a very different pattern than that documented in other regions of the globe, possibly attributable to a long history of coexistence.

Organization of Squamata (Reptilia) assemblages in Mediterranean archipelagos.

Mediterranean islands have complex reptile assemblages, but little is known about the factors that determine their organization. In this study, the structure of assemblages of Squamata was evaluated based on their species richness and two measures of phylogenetic diversity (variability and clustering). I evaluated the composition of the assemblages comparing distinct biogeographic subregions within the Mediterranean: Adriatic, Aegean, Balearic, Corsica-Sardinia, Crete, Gulf of Gabés, Ionian Sea, Ligurian Sea, Malta, Sicily, and Tyrrhenian Sea. The effect of island environments and geographical isolation on the diversity metrics was assessed using generalized linear models. The analyses indicated that species richness was mostly influenced by island area and geographical isolation. Assemblages on smaller islands were poorer in species and phylogenetically dispersed, possibly as an effect of interspecific competition. The species composition of the assemblages was determined by similar environmental drivers within the biogeographic subregions, including island area, island elevation, geographical isolation, and aridity. In several subregions, significant patterns of phylogenetic attraction were found in species co-occurrences, caused by the limits imposed by the island size on large predatory species.

A new subspecies of African fire salamander Salamandra algira (Urodela, Salamandridae) from the Middle Atlas Mountains, Morocco.

A new subspecies within the Salamandra algira species complex from north-western Africa is described. Previous molecular analysis showed that the populations of S. algira splendens from north-western Morocco consisted of two well supported clades: clade 1 distributed in the Rif Mountains, from Chefchaouen (type locality) to Al Hoceima, and clade 2, located southern from clade 1 being isolated in the northern and central Middle Atlas Mountains. Clade 2 is herein described as a distinct subspecies: Salamandra algira atlantica ssp. nov. based on morphological data, allopatric range and molecular divergence. This new subspecies shows an uncorrected pairwise distance of 0.0265 from clade 1 based on cytochrome b DNA sequences. Salamandra algira atlantica ssp. nov. is a slender and large sized salamander with a highly variable colouration pattern. It can be distinguished from S. algira splendens by the greater proportion of coral red in the background colouration, being the only known subspecies of S. algira in which coral red can exceed the proportion of black. Variable number (0-5) of yellow to golden yellow dorsal blotches, but usually in lower numbers than the nominotypical subspecies. Salamandra algira atlantica ssp. nov. inhabits subhumid to humid forests and karstic systems at mid to high elevations. We briefly discuss the phylogenetic and taxonomic issues among the genus Salamandra which encompasses more valid species than currently recognised.

Habitat use in south-west European skinks (genus Chalcides).

BACKGROUND: Congeneric species of reptiles frequently exhibit partitioning in terms of their use of habitats or trophic resources in order to reduce competition. In this study, we investigated habitat use by two species of European skinks: Chalcides bedriagai and Chalcides striatus, based on 49 records from southern France, Spain, and Portugal. METHODS: We measured three levels of niche descriptors: macroscale (climate, topography, and substrate), mesoscale (plant associations), and microscale (vegetation cover and shelters). We assessed the associations between these environmental descriptors and the occurrence of the skinks. RESULTS: Our results showed that the two species occupied opposite extremes of the ecological gradient i.e., C. bedriagai in semi-arid environments and C. striatus in temperate-oceanic environments, but there was broad ecological overlap in transitional climates at all of the habitat scales examined. This overlap was demonstrated by the presence of syntopy in geographically distant sites with different environmental characteristics. DISCUSSION: The morphological differences between the two species, and possibly their different use of microhabitats, might favor this mesoscale overlap between congeneric species, which is relatively unusual in Mediterranean lizards.

Comparative larval morphology in three species of Pleurodeles (Urodela: Salamandridae).

The Ribbed newts (genus Pleurodeles) are endemic to the Iberian Peninsula and northwest Africa (Raffaëlli 2013), and comprise three species: Pleurodeles nebulosus (Guichenot 1850), Pleurodeles poireti (Gervais 1836) and Pleurodeles waltl Michahelles 1830. Pleurodeles nebulosus is found in northern Algeria and Tunisia with an average size of 18 cm, while P. poireti is endemic to the Edough Massif, in northeastern Algeria and is the smallest species, with 12.9 cm in total length (Escoriza et al. 2016; Carranza & Wade 2004). Pleurodeles waltl appears on the Iberian Peninsula and Morocco (García-París et al. 2004). The eastern and western populations of P. waltl although they are not differentiated taxonomically show high levels of genetic divergence (estimated to have occurred 2.0-3.2 Ma; Carranza & Arnold 2003). The individuals of P. waltl attain large sizes (30 cm of total length) and have 8-10 cutaneous glands on both sides (Pasteur 1958), which are absent in other species of the genus.

Diversity of Guilds of Amphibian Larvae in North-Western Africa.

The composition and diversity of biotic assemblages is regulated by a complex interplay of environmental features. We investigated the influence of climate and the aquatic habitat conditions on the larval traits and the structure of amphibian larval guilds in north-western Africa. We classified the species into morphological groups, based on external traits: body shape, size, and the relative positions of the eyes and oral apparatus. We characterized the guild diversity based on species richness and interspecific phylogenetic/functional relationships. The larvae of the urodeles were classified as typical of either the stream or pond type, and the anurans as typical of either the lentic-benthic or lentic-nektonic type. The variations in the body shapes of both urodeles and anurans were associated with the type of aquatic habitat (lentic vs lotic) and the types of predators present. Most of the urodele guilds (98.9%) contained a single species, whereas the anuran guilds were usually more diverse. Both the phylogenetic and functional diversity of the anuran guilds were positively influenced by the size of the aquatic habitat and negatively by aridity. In anurans, the benthic and nektonic morphological types frequently co-occurred, possibly influenced by their opportunistic breeding strategies.

Linderiella jebalae sp. nov. (Crustacea: Branchiopoda: Anostraca), a new species from the Rif mountains (northern Morocco).

A new species of fairy shrimp, Linderiella jebalae sp. nov., was found in temporary ponds located in the Rif region of northern Morocco. Morphological characters of females, such as the basal long warty outgrowth of the antennae, the highly developed cuticular papillae in the second genital segment, and the presence of a keel-shaped process directed posteriorly in dorsal side of the brood pouch, clearly distinguish this species from the others of the genus. In the case of males, the basiomedial antennal outgrowth and the distal segment of the antenna are diagnostic features for the species. Cyst ornamentation, characterized by thick, blunt and sometimes truncated spines, also separate this species. This is the fourth known Palaearctic Linderiella species, all of them described recently (from 1980s onwards) and located in a restricted area, from south-eastern France to Iberian Peninsula and Morocco.

Review of the systematics, distribution, biogeography and natural history of Moroccan amphibians.

The amphibian fauna of the Kingdom of Morocco was traditionally regarded as poor and closely related to its European counterpart. However, an increase in research during the last decades revealed a considerable degree of endemism amongst Moroccan amphibians, as well as phenotypic and genotypic inter- and intraspecific divergence. Despite this increase in knowledge, a comprehensible overview is lacking while several systematic issues have remained unresolved. We herein present a contemporary overview of the distribution, taxonomy and biogeography of Moroccan amphibians. Fourteen fieldtrips were made by the authors and colleagues between 2000 and 2012, which produced a total of 292 new distribution records. Furthermore, based on the results of the present work, we (i) review the systematics of the genus Salamandra in Morocco, including the description of a new subspecies from the Rif- and Middle Atlas Mountains, Salamandra algira splendens ssp. nov.; (ii) present data on intraspecific morphological variability of Pelobates varaldiiand Pleurodeles waltl in Morocco; (iii) attempt to resolve the phylogenetic position of Bufo brongersmai and erect a new genus for this species, Barbarophryne gen. nov.; (iv) summarize and assess the availability of tadpole-specific characteristics and bioacoustical data, and (v) summarize natural history data.