Aquatic insects are important in the function of ecosystem. The objective of this study is to describe the structure and distribution of aquatic insects in four rivers which are located on three different slopes of the Sierra Nevada de Santa Marta (SNSM): Gaira, Tucurinca, Ranchería and Guatapurí. Gravel and macrophyte microhabitats were analyzed in each river with a Surber sampler, the leaf litter fauna with a triangular net, and spray zones and stones were analyzed by manual collection. 5803 individuals were registered, 39 families and 72 taxas. Guatapurí River presented the greatest abundance number (1890 individuals). The most abundant order was Ephemeroptera with 1861 individuals. Simulium presented the higher abundance (14.5 %) . The higher abundance was in the gravel 36.93 % and lowest in litter with 33.31 %. We found high abundance during the low rainfall (Guatapurí and Ranchería). Two new records were obtained, Podonomus (Chironomidae) in Guatapurí River and Stenhelmoides (Elmidae) in Ranchería River. According to the results we could conclude that the rivers of the SNSM have a high generic richness compared with the Andean Zone Rivers and other temperate zones.
Tópico:
Freshwater macroinvertebrate diversity and ecology