Functional feeding groups of Chironomidae (Diptera: Nematocera) and their spatial variation in an intermittent hill stream (Ventana stream, Buenos Aires, Argentina)

OCON CAROLINA; SIRI AUGUSTO; ALTIERI PAULA; DONATO MARIANO

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2023

0001-3765

Feeding habits of Chironomidae for hill streams in the Pampean regionare unknown. In this study, we analyzed gut contents of this family with the aim toestablish the diet of in a stream along an altitudinal gradient. Three sampling sites wereestablished: site A (574 m a.s.l.), site B (518 m a.s.l.) and site C (320 m a.s.l). The onlyspecies found at the three sites was Corynoneura sp1. The food items were detritus,diatoms, filamentous chlorophytes, euglenophytes, vascular plants, fungi and animalremains. The higher richness (S) of food items was registered for Podonomus gr.decarthrus (S: 6) and the lowest (S: 2) for Corynoneura sp1 (sites A and C), thediversity showed the same behavior. The higher dominance index was observed forCorynoneura sp1 in site A and the higher equitability was registered for the samespecies in site C. No differences in feeding habits attributable to an altitudinal gradientcould be recognized. Most of the species could be classified as gathering-collectors,with a higher proportion of detritus in their gut contents. However, Pentaneura nrcinerea, Cricotopus sp1 (site B) and Onconeura analiae (site C) had high proportions ofanimal remains (between 30 and 44%).