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Animals living on small islands are more drastically exposed to environmental changes, such as food or water starvation, and rapid temperature shifts. Facing such conditions, and probably thank to adaptive plasticity mechanisms, some animals display a Reversed Island Syndrome (RIS), a suite of traits, including skin pigmentation, voracity, sexual dimorphism, showed differently from mainland relatives. Here, we analyse a so far poorly explored aspect of RIS: the effect of this on the microbiota composition of host Italian wall lizard (Podarcis siculus), strongly influenced by the animal’s lifestyle, and conditioning the same. We compare mainland and island populations, assessing the difference between their microbial communities and their response under unexpected food, experimentally provided. Our observations showed a significant difference in microbiota communities between island and mainland groups, depended mainly from changes in relative abundance of the shared genera (difference due to decrease/increase). Exposure to experimental diet regimes resulted into significative reshaping of bacterial composition of microbiota and a greater variation in body mass only in the island population. Our results could be an evidence that gut microbial community contributes to adaptive plasticity mechanisms of island lizards under RIS to efficiently respond to unexpected changes.

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Background: New epidemiological data on bacterial and parasitic infections in 24 Italian wall lizards, namely Podarcis sicula (mainland population) and P. sicula klemmerii (insular population) in southern Italy were provided. To achieve this goal, samples were collected from individuals belonging to the two populations and analysed by microbiological and parasitological methods. Results: A wide range of bacteria (e.g. Pantoea spp., Citrobacter spp., Morganella spp., Pseudomonas, Enterobacter spp., Staphylococcus spp. And Escherichia coli) and parasites (e.g. Ophionyssus natricis, coccidia, Dicrocoelidae) were detected in both P. sicula and P. sicula klemmerii individuals. Insular population presented similar bacterial and parasitic diversity to its mainland counterpart. Ampicillin was the antimicrobial with the highest resistance rate. Conclusion: This study highlighted various bacteria and parasites, some of them potentially zoonotic. Further studies are needed to better understand the epidemiology and transmission routes of these pathogens along with their impact on the welfare and behaviour of Italian wall lizards.

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Only some island populations of Podarcis sicula are hyperchromatic. The study of this phenome- non and its relationship with the lizards of the mainland and other islands, exhibiting a “normal” coloration, provides useful hints in our understanding of evolutionary mechanisms that have cre- ated the observed morphological variation. We performed a comparative morphological and genetic analysis of a hyperchromatic lizard population from Licosa Island, and compared the data with that obtained from normal-colored lizard populations both from Ustica and Cirella islands in the Tyrrhenian sea and from nearby mainland Italy. Morphological and microsatellite gene differentiation in the hyperchromatic Licosa population appears to have been much more rapid than the molecular evolution of the mtDNA. We discuss herein that the comparison of hyperchromatism and other types of morphological variation with molecular data in island populations of lizards may provide useful hints as to evolutionary mechanisms.

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The island syndrome is a phenomenon in which high density island populations exhibit reduced aggression, decreased sexual dimorphism and decreased energy allocation to reproduction. The reversed island syndrome was observed in a fluctuating density, blue coloured population of Podarcis siculus klemmeri, which had higher levels of aggressivity and sexual dimorphism. The aim of this seminar paper was to compare the behavioral traits of tolerance, aggressivity and retreat in island and mainland population of Italian wall lizard (Podarcis siculus) by analyzing video-recordings of conducted behavioral trials in an open-type arena. The island population consisted of 5 pairs of males from the Pijavica island and the mainland population of 5 pairs of males from Kaštela. Males of high density population of the Pijavica island are normally coloured, while those of the land population have blue and yellow coloration of the ventral part of the body and head. During the analysis, all encounters were recorded and assigned to a predefined type and category of behavior. Males from the island population had 100 % tolerant encounters, while 3 pairs of land population showed encounters of aggressivity and retreat. Former characteristics of the island population correspond to the definition of island syndrome, which can be explained by reduced predation pressure and decreased interspecific competition.

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The morphology of the adrenal gland and relationships between noradrenalin (NA) and adrenalin (A) cells were studied in selected species of the genus Podarcis. As in other previously-studied genera, the morphology of the adrenal gland is not homogeneous, and the species examined can be divided into two groups according to the relationship between chromaffin and steroidogenic tissue. Podarcis taurica and P. hispanica, in which the two tissues are strongly separated, belong to one group. P. wagleriana, P. muralis, P. sicula, P. peloponnesiacus and P. melisellensis belong to a second group in which dorsal chromaffin ribbons send digitations between the steroidogenic cords. The NA/A cell ratio is higher in species of the first group than in those of the second.

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Description of Lacerta sicula klemmeri n. subsp. from the islet of Licosa (about 50 km south of Salerno, Campania, Italy, Thyrrhenian Sea), a blue-bellied, feebly melanistic, patternless, giant sicula-species, distinguished from the other strongly blue- bellied races of the same species as follows: L. sicula klemmeri n. subsp.: much !arger than L. s. paulae and L. s. salfii (maximum head and body length: 8 85 mm, S2 78 mm); dorsally reticulated or striated specimens lacking; less melanistic than L. s. coerulea, L. s. salfii and L. s. paulae; on the whole less cyanistic than L. s. coerulea and L. s. paulae; scutum massetericum always present; mid- body scales: 8 68-73 (69,8), S2 59-70 (64,5). L. sicula coerulea (EIMER) (islets Faraglione di Fuori and Faraglione di Mezzo, near the island of Capri, Prov. of Napoli, Campania): same size; dorsally reticulated or striated specimens present; more melanistic and, on the whole, more cyanistic than L. s. klemmeri; scutum massetericum almost always present; midbody scales: 8 67-79 (73,4), S2 67-71 (68,6). L. sicula paulae LANZA, ADRIAN! & RoMrTI (islet S. Ianni, 3 km south of Maratea, Lucania): much smaller than L. s. klemmeri (maximum head and body length: 8 71 mm, S2 66 mm); all the population is dorsally reticulated; more melanistic and, on the whole, more cyanistic than L. s. klemmeri; scutum massetericum almost always lacking or, if present, extremely small; midbody scales: 8 73-78 (75,7), 76 in the only known female. L. sicula salfii LANZA (islet Vivaro di Nerano, Gulf of Salerno, Campania): much smaller than L. s. klemmeri (maximum head and body length: 8 78 mm, S2 72 mm); all the population is dorsally reticulated; more melanistic than L. s. klemmeri; scutum massetericum always present; midbody scales: 8 65-73 (68,5), S2 61-70 (66,0). Some of the less cyanistic specimens of L. s. klemmeri (halfgrown ones!) look like ehe patternless and more cyanistic individuals of L. sicula mertensi WETTSTEIN, a feebly differentiated continental race inhabiting the region of Paestum, Giungano and Capac- cio in the Gulf of Salerno.

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The birth and development of the herpetology collection of theMuseo di Storia Naturale of the University of Florence are described. Early specimens, mainly turtles’ shells, date from the eighteenth century and are no longer found in the museum. At present the collection includes about 26,500 amphibians and 40,000 reptiles; it mostly increased at the end of 1800, due to Enrico Hillyer Giglioli’s work, and in the second part of the twentieth century, as a result of the studies of Benedetto Lanza and his colleagues. The most important specimens of the typical material are also mentioned.

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The chromosome C-banding pattern has been studied in four lacertid species possessing the same karyotype. The results obtained show a remarkable interspecific variability both in the amount and distribution of C-banded heterochromatin. This leads us to the speculation that alleged conservativeness in their karyology is probably due to inadequate resolution by the conventional cytological techniques. Moreover, it has been hypothesized that these variations of the C-bands play an important role in the evolution of this saurian family.

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The karyology of various species from the family Lacertidae (Reptilia, Sauria) has been studied with conventional and C-banding techniques. The study shows that this family is not so conservative from a karyological viewpoint as considered till now. In fact a higher diploid number than that generally observed in most species of Lacertidae and supernumerary chromosomes have been observed in three of the species investigated. Moreover an evident interand intraspecific variability has been found in the C-banding pattern of the various species studied. The situation found in Podarcis sicula is particularly remarkable. Different C-banding patterns have been observed in three different subspecies and in two populations of the same subspecies. These variations do not show a well defined trend and their role in the evolution of lacertid lizards is discussed. The C-banding analysis evidences also the existence in two of the species studied of a female sex heteromorphism, in which the W chromosome has the same shape and size as the Z, but differs from it in being completely heterochromatic. This situation reminds that observed in some snakes and suggests that in lacertid lizards the evolution of sex chromosomes might have followed the same steps previously hypothesized for ophidians.

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Background: Many small vertebrates on islands grow larger, mature later, lay smaller clutches/litters, and are less sexually dimorphic and aggressive than their mainland relatives. This set of observations is referred to as the ‘Island Syndrome’. The syndrome is linked to high population density on islands. We predicted that when population density is low and/or fluctuating insular vertebrates may evolve correlated trait shifts running opposite to the Island Syndrome, which we collectively refer to as the ‘reversed island syndrome’ (RIS) hypothesis. On the proximate level, we hypothesized that RIS is caused by increased activity levels in melanocortin receptors. Melanocortins are postranslational products of the proopiomelanocortin gene, which controls pleiotropically pigmentation, aggressiveness, sexual activity, and food intake in vertebrates. Results: We tested the RIS hypothesis performing a number of behavioral, genetic, and ontogenetic tests on a blue colored insular variant of the Italian Wall lizard Podarcis sicula, living on a small island off the Southern Italian coast. The population density of this blue-colored variant was generally low and highly fluctuating from one year to the next. In keeping with our predictions, insular lizards were more aggressive and sexually dimorphic than their mainland relatives. Insular males had wide, peramorphic heads. The growth rate of insular females was slower than growth rates of mainland individuals of both sexes, and of insular males. Consequently, size and shape dimorphism are higher on the Island. As predicted, melanocortin receptors were much more active in individuals of the insular population. Insular lizards have a higher food intake rate than mainland individuals, which is consistent with the increased activity of melanocortin receptors. This may be adaptive in an unpredictable environment such as Licosa Island. Insular lizards of both sexes spent less time basking than their mainland relatives. We suspect this is a by-product (spandrel) of the positive selection for increased activity of melanocortins receptors. Conclusions: We contend that when population density is either low or fluctuating annually as a result of environmental unpredictability, it may be advantageous to individuals to behave more aggressively, to raise their rate of food intake, and allocate more energy into reproduction.

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Some insular lizards show a high degree of differentiation from their conspecific mainland populations, like Licosa island lizards, which are described as affected by Reversed Island Syndrome (RIS). In previous works, we demonstrated that some traits of RIS, as melanization, depend on a differential expression of gene encoding melanocortin receptors. To better understand the basis of syndrome, and providing raw data for future investigations, we generate the first de novo transcriptome of the Italian wall lizard. Comparing mainland and island transcriptomes, we link differences in life-traits to differential gene expression. Our results, taking together testis and brain sequences, generated 275,310 and 269,885 transcripts, 18,434 and 21,606 proteins in Gene Ontology annotation, for mainland and island respectively. Variant calling analysis identified about the same number of SNPs in island and mainland population. Instead, through a differential gene expression analysis we found some putative genes involved in syndrome more expressed in insular samples like Major Histocompatibility Complex class I, Immunoglobulins, Melanocortin 4 receptor, Neuropeptide Y and Proliferating Cell Nuclear Antigen.