Adriana Bellati

Colour Polymorphism and Alternative Breeding Strategies: Effects of Parent’s Colour Morph on Fitness Traits in the Common Wall Lizard

Colour polymorphism (CP) is widespread in animals, but mechanisms underlying morph evolution and maintenance are not completely resolved. In reptiles, CP is often genetically based and associated with alternative behavioural strategies, mainly in males for most cases. However, female colour morphs also display alternative reproductive strategies associated with behavioural and physiological traits, which may contribute to maintain CP in the population. Both sexes of the common wall lizard (Podarcis muralis) show three pure colour morphs, white, yellow and red. Here, we looked for the effects of male and female colour morphs on fitness traits of captive-breeding pairs. All yellow-throated females laid clutches of many small eggs and produced many light offspring, behaving as r-strategists, whereas white-throated females laid clutches of few large eggs and produced few heavy offspring, behaving as K-strategists. Red-throated females adopted a conditional Kr-strategy depending on their size/age. These basic female strategies were modulated in relation to mate morph: white females had the best fitness gain in terms of viable offspring when mated to red males; mating between yellow morphs yielded a greater breeding success than all other morph crosses, but also lighter offspring; finally, red females produced heavy progeny when paired with red or white males, and light offspring in pair with yellow males. Thus, correlation between CP and traits relevant to fitness combined with non-random mating, either assortative or disassortative, could increase the potential for CP to contribute to divergent evolution in the common wall lizard.

An ancient lineage of slow worms, genus Anguis (Squamata: Anguidae), survived in the Italian Peninsula

Four species of legless anguid lizard genus Anguis have been currently recognized: A. fragilis from western and central Europe, A. colchica from eastern Europe and western Asia, A. graeca from southern Balkans, and A. cephallonica from the Peloponnese. Slow worms from the Italian Peninsula have been considered conspecific with A. fragilis, despite the fact that the region served as an important speciation center for European flora and fauna, and included some Pleistocene glacial refugia. We used mitochondrial and nuclear DNA sequences to investigate the systematic and phylogenetic position of the Italian slow-worm populations and morphological analyses to test for phenotypic differentiation from A. fragilis from other parts of Europe. Our phylogenetic analyses revealed that Italian slow worms form a distinct deeply differentiated mtDNA clade, which presumably diverged during or shortly after the basal radiation within the genus Anguis. In addition, the specimens assigned to this clade bear distinct haplotypes in nuclear PRLR gene and show morphological differentiation from A. fragilis. Based on the differentiation in all three independent markers, we propose to assign the Italian clade species level under the name Anguis veronensisPollini, 1818. The newly recognized species is distributed throughout the Italian Peninsula to the Southern Alps and south-eastern France. We hypothesize that the Tertiary Alpine orogeny with subsequent vicariance might have played a role in differentiation of this species. The current genetic variability was later presumably shaped in multiple glacial refugia within the Italian Peninsula, with the first splitting event separating populations from the region of the Dolomite Mountains.

Sex Discrimination of Crab Plovers (Dromas ardeola) by Morphometric Traits

Abstract. Determining the sex of Crab Plovers (Dromas ardeola) based on morphology has, hitherto, proven difficult. Here, six morphological traits (head-bill length, bill length, bill depth, wing chord, tarsus length and weight) of 39 molecularly or behaviorally sexed breeding Crab Plovers were compared in order to find a reliable morphometric way to determine their sex. Males were significantly larger than females in all traits, except tarsus length, and especially in traits related to head and bill size, where males were 6.8 to 11.4% larger than females. Discriminant Function Analysis correctly classified 97.4% of birds using only bill depth and bill length, providing an efficient tool for sexing Crab Plovers in the hand.

Urbanization affects refuge use and habituation to predators in a polymorphic lizard

Prey–predator interactions are plastic behaviours shown by both players, which constantly modify their decisions depending on physiological conditions and ecological context. We investigated whether the behavioural response to repeated simulated predatory attacks varied between adult males of the common wall lizard, Podarcis muralis, inhabiting environments characterized by different degrees of human presence. Our aim was to detect possible effects of urbanization on antipredator responses, in terms of activity, time spent hidden in refuges and habituation. Moreover, since this lizard species exhibits intrapopulation colour polymorphism, we looked for the occurrence of possible correlations between antipredator strategy and individual ventral coloration. We found that urban lizards spent less time in their refuge after predatory attacks and decreased successive hiding times faster than rural lizards, suggesting different wariness towards a potential predator. Irrespective of population, yellow lizards gradually spent less time in the refuge before appearing and emerging outside than the other two morphs. Conversely, red lizards showed progressively longer appearance and emergence times after successive tests, suggesting a growing sensitization to the potential threat of a predatory attack. In conclusion, our study showed the occurrence of different levels of behavioural plasticity in common wall lizards antipredator response: the population level, depending on ecological context, here different degrees of exposure to human disturbance, and the individual level, which suggests the occurrence of morph-specific antipredator strategies. Thus, using a lizard species as a model, we shed light on two key points of evolutionary ecology concerning both the antipredator response and the factors driving the maintenance of intraspecific polymorphism.

Complexity of biogeographic pattern in the endangered crayfish Austropotamobius italicus in northern Italy: molecular insights of conservation concern

The protection of freshwater biodiversity has become a priority task for conservation practices, as freshwater ecosystems host high levels of cryptic diversity, while also record similarly high rates of extinction. The Italian white-clawed crayfish Austropotamobius italicus is an endemic freshwater crustacean, threatened by several anthropogenic impacts such as habitat fragmentation, pollution, invasion of exotics, and climate change. Previous phylogenetic studies conducted in Italy pointed out a complex phylogeographic framework for the species, with four different subspecies currently recognized. Conservation efforts, particularly when involving restocking and reintroduction, require a detailed knowledge of their population genetics. In this study we describe the genetic structure of A. italicus populations in northern Italy (Lombardy Alpine foothills and northern Apennines) by using the informative mitochondrial marker cytochrome c oxidase subunit I, in order to assess their current evolutionary diversity and past phylogeographic history from a conservation perspective. Our results contribute to the mapping of the contact area among A. i. carsicus and A. i. carinthiacus in the Orobie Larian Prealps. More interestingly, we highlight the existence of two deeply differentiated evolutionary lineages within A. i. carsicus, showing alternative phylogeographic patterns and past demographic trends. We propose to consider these two clades as distinct molecular operational taxonomic units for the conservation of this endangered crayfish.

Fishes in the desert: mitochondrial variation and phylogeography of Danakilia (Actinopterygii: Cichlidae) and Aphanius (Actinopterygii: Cyprinodontidae) in the Danakil Depression of northeastern Africa

Abstract The Danakil Depression in northeastern Africa represents one of the harshest arid environments on Earth, yet two genera of fishes, Danakilia (Cichlidae) and Aphanius (Cyprinodontidae), share its sparse aquatic habitats. The evolutionary history of these fishes is investigated here in the context of genetic, geological and paleoenvironmental information. We collected samples from seven sites and assessed phylogeographic relationships using concatenated COI and cytb mtDNA genes. Danakilia morphospecies show low differentiation at mitochondrial markers, but variation is partitioned between a northern cluster containing D. dinicolai plus three undescribed riverine populations, and a southern cluster including two creek populations of D. franchettii separated by the hypersaline waters of Lake Afrera. Aphanius displayed four genetically distinct clades (A. stiassnyae in Lake Afrera; one distributed across the entire area; one in Lake Abaeded; and one in the Shukoray River), but without clear large-scale geographic structure. However, Danakil Aphanius are clearly differentiated from A. dispar sensu stricto from the Sinai Peninsula. Geological evidence suggests that after the Late Pleistocene closure of the Danakil-Red Sea connection, increased post-glacial groundwater availability caused the formation of a brackish paleo-lake flooding the entire region below the –50 m contour. Fish populations previously isolated in coastal oases during glaciation were able to mix in the paleo-lake. Subsequently, in a more arid phase starting ∼7300 BP, paleo-lake regression isolated fishes in separate drainages, triggering their still ongoing diversification.