Species Distribution Modeling And Assessment of Environmental Drivers Responsible To Distribution And Preferred Niche of Critically Endangered Endemic Ornamental Freshwater Fish Species of The Genus Sahyadria

Abstract

\n India has different bio-climatic zones that support diverse aquatic habitats rich in biodiversity. For effective conservation of endangered species in its habitat, it is essential to know the distribution of the fish species in the environmental range and for this species distribution models are the efficient and innovative tools. The present study used MaxEnt model to develop the probability distribution model highlighting the distribution of the fish species by analyzing the known occurrence records of Denison barb under genus Sahyadria (Sahyadria denisonii Day 1865 and Sahyadria chalakkudiensis (Menon, Rema Devi & Thobias 1999)) in relation to environmental variables typically incorporating seasonal and temporal variability. AUC of the models for Sahyadria species depicted good fitness. Both the species were found sensitive to Solar radiation , Temperature seasonality and Temperature annual range and these variables were assessed as the significant predictors. The sensitivity of distribution of both species to these environmental variables was found correlated with their breading and spawning seasons. Precipitation was determined as a significant climatic envelop influencing distribution of the species associated with the river flow. The models showed that distribution of S. denisonii in the higher precipitation areas compared to S. chalakkudiensi. The probability distribution model with respect to distribution of both the species indicates a lineage barrier at Palghat Gap supporting the studies of earlier workers. At the latitudinal scale, prediction of the suitable ecological habitat provides the detailed insight into the distribution of all the genetic lineages of the genus Sahyadria. Evidently, the findings of this study can assist in determining ecological niches for other threatened and endangered species of other areas and may aid in field surveys as well as developing conservation plans.