Plasma and tissue enzyme activities of banded water snakes (Nerodia fasciata) and diamondback water snakes (Nerodia rhombifer)

OBJECTIVE To measure plasma and tissue activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase (AST), creatine kinase, and γ-glutamyltransferase in 2 snake species. ANIMALS 6 banded water snakes (Nerodia fasciata) and 6 diamondback water snakes (Nerodia rhombifer). PROCEDURES Blood was collected via the ventral tail vein to measure plasma enzyme activities. Animals were then euthanized, and samples of 9 tissues were collected from each snake: skeletal muscle, cardiac muscle, liver, spleen, lung, kidney, testicle, pancreas, and gallbladder. Tissues were frozen for 30 days, then homogenized and processed. Supernatants were collected and analyzed within 24 hours of processing. A linear mixed model was used to determine differences in enzyme activity between tissues and species and assess interactions between tissues and species. RESULTS Activities of all enzymes were found to differ significantly among tissues. There were also significant differences between species for all enzyme activities, except AST activity. The kidney had the highest alanine aminotransferase and γ-glutamyltransferase activities. Alkaline phosphatase activity was significantly highest in liver and kidney tissues than in other tissue. Creatine kinase activity was highest in skeletal muscle, followed by cardiac muscle and kidney. AST activity was present in all tissues evaluated, but was highest in liver, kidney, and cardiac muscle in both species. CLINICAL RELEVANCE Results reinforced the importance of characterizing the origin of tissue enzymes in reptiles to improve our understanding of biochemistry results and highlighted the differences that can exist in tissue enzyme activities between closely related species.

Taxonomy, allometry, sexual dimorphism, and conservation of the trans-Andean water-snake Helicops danieli Amaral 1937 (Serpentes: Dipsadidae: Hydropsini).

The extensive lack of knowledge on the morphological aspects of South American water-snakes, includes a poor understanding of phenotypic parameters, intraspecific variation, and conservation of the trans-Andean Helicops species, Helicops danieli Amaral, 1937. For the first time, we provide a multidisciplinary view using key features (e.g., morphology and niche modeling) to improve the taxonomic recognition of this species, as well as describing ontogenetic color changes, allometry, sexual dimorphism, and the conservation status of this poorly studied snake. First, we emended the morphological diagnosis of H. danieli with 23 characters and detected that juvenile tail length is positively related to allometric growth, and that juveniles differ from adults through the presence of the white nuchal collar. Females are larger than males for snout-vent length, whereas males showed proportionally longer tails and smaller head length growth. Suitable areas for H. danieli are restricted to the trans-Andean regions from the Magdalena drainage to the Caribbean coast, which also showed high values of anthropic impacts. Our multidisciplinary approach provided new insights into this South American water snake’s morphology, intraspecific variation, and distribution.

THE ANTHROPOGENIC ADAPTATION INDEX OF REPTILES IN URBANIZED AREAS OF THE ASHBERON PENINSULA

The strong urbanization of Absheron peninsula highlights the urgency of studying the level of adaptation of reptiles that characterize these areas. Therefore, we have aimed to study the degree of anthropogenic adaptation of each reptile species inhabiting the peninsula. The anthropogenic adaptation index of separate reptiles in the Absheron Peninsula is different in terms of reproductive strategy. Thus, relatively high adaptive anthropogenic intensity is observed in the Caspian bent-toed geckoes (24.5) which are habitats of single-storey buildings, moderately adapted water snakes (17.2), and poorly adapted Mediterranean turtles (10.4). In the mixed-storey residential area, the anthropogenic adaptation were 21.4, 12.8 and 3.7 respectively in geckoes, water snakes and turtles. The anthropogenic adaptation was 0 due to the absence of water snakes and Mediterranean turtles in the residential area with multi-storey buildings, but the Caspian bent-toed gecko was rarely found (1,3). In the area of industrial facilities, the Caspian bent-toed gecko predominates over the reptile species studied, but the level of anthropogenic adaptation in woodlands and control area was much lower.

Diet of the Lesser Spotted Eagle (Clanga pomarina) in Amvrakikos Wetlands National Park, Greece

The diet of the lesser spotted eagle (Clanga pomarina) was studied in the area that is now the Amvrakikos Wetlands National Park during the Spring periods of 2000 and 2002 by analysis of pellets and prey remains found at two active nest sites, in two different territories. Among 155 prey items collected, in terms of biomass, the diet was 43% reptiles, 30% birds, 24% mammals, 3% amphibians and 1% arthropods. The most important prey taxa were brown rat (Rattus norvegicus) at 19%, water snakes (Natrix spp.) at 11% and moorhen (Gallinula chloropus) at 11% composition. Despite a wide availability of semi-natural and agricultural habitats around the immediate nesting areas, the species seems to have invested in foraging largely on water-dependent animals. The species maintained only one or a maximum of two pairs in the wider region during the study, this being at the southwestern margin of its global breeding range. Conservation insights and recommendations are presented.

Feeding Ecology of Short-Toed Snake-Eagle (Circaetus gallicus [Gmelin, 1788]) in the Montados of Iberian Peninsula

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.