Abstract

According to our recent research, 125 fish species (109 native, two transferred from freshwater and 14 marine and brackish) living in the Colombian-Venezuelan Catatumbo basin (southern Maracaibo Lake). This is the most fish-diverse system in the Lake Maracaibo basin (LMb); 181 species have been recorded. In this work we record 14 marine and estuarine species. Of these Dasyatis guttata and Microphis lineatus are new to the Catatumbo and the Lake Maracaibo (LM), respectively. The presence of these marine and brackish species is due to the increasing salinization process of LM (mostly freshwater) during the last 60 years as a result of human intervention, through three causes: i) The construction and dredging of a navigation channel-inlet in the LM of large oil tankers and merchant, ii) Modifying the flow of rivers flowing into the LM, the product of direct extraction of water from natural streams and subterranean sources, and the realization of large reservoirs for industrial, agricultural and human use, and iii) Extensive deforestation. These interventions cause: i) Increasing seawater into LM, ii) Great debts in the runoff from watersheds, and iii) Major changes in natural seasonality of runoff regime, now tending to concentrate only for short spaces of time during greatest annual rainfall. Comprehensive inventories in the areas of flood or mouths of various tributaries of the LM, highlight the presence of marine and brackish fish fauna and thus increase the diversity of species so far known. KEY WORDS: Biodiversity, new records, marine and brackish species, Catatumbo river basin, Lake Maracaibo

PDF Preview