Reptiles

GIRAUDO, ALEJANDRO R.; ARZAMENDIA, V.; SOLEDAD M. LOPEZ

The Middle Paraná River: Limnology of a subtropical wetland

Springer-Verlag

Lugar: Berlin Heidelberg New York; Año: 2007; p. 341 - 362

There are animal groups that have the function of relating aquatic and terrestrial ecosystems: reptiles are one of them. Aquatic ecosystems and their species have traditionally been studied separately from terrestrial systems that surround them. This scope was necessarily modified to study of the great South American rivers and their floodplains, due to the importance of the interaction between aquatic and terrestrial phases to understand their functioning. We analyzed the reptile community of the Middle Paraná River floodplain (MPR), including aspects of species richness, its main ecological traits and the influence of the flood-pulse and other environmental variables in the reptile community. The MPR, although it is located in a subtropical-temperate region, shows high reptile richness (71 species), comparable with values registered in tropical South America megadiverse areas. The gradual loss of reptile species was observed when latitude increased, is probably related with the decrease in temperature. The MPR is a biogeographical transition area where tropical faunistic elements, that reach higher latitudes through the river, and faunistic elements from subtropical and temperate biogeographical regions. We observed some differences in their reproductive strategies of a terrestrial and oviparous snake and an aquatic and viviparous snake, probably in adjusted to historical flood-pulse. Adaptations of reptiles that can favor their survival in pulsatile and variable environments: high metabolic efficiency to transform food in biomass, prolonged capacity of starvation in moments of food scarcity, capacity of adjusting their reproduction to environmental variations and food abundance. Several aquatic reptiles are abundant in the Middle Paraná River, and many of their life cycles are strongly influenced by the flood pulses. Nevertheless, unlike to reptiles communities in the Amazonia, the community of the MPR was strongly influenced by the seasonality in temperature and precipitations.