First observations on crustaceans in a small, permanent coastal lagoon (Nigue, 39°S, Araucania region, Chile)

Los crustáceos zooplanctónicos en lagunas costeras chilenas ha sido poco estudiado y los escasos estudios indicarían un bajo número de especies en función de las condiciones tróficas. El objetivo del presente estudio es hacer una primera caracterización de crustáceos en una laguna costera pequeña usando modelos nulos, específicamente co-ocurrencia de especies y sobreposición de nicho. Los resultados revelaron que las asociaciones de especies son aleatorias, mientras que la sobreposición de nicho reveló que los nichos de las especies están segregados debido a la ausencia de competencia entre especies. Estos resultados serían similares a observaciones para lagos y lagunas de montaña del norte de la Patagonia de Argentina y Chile. Sería necesario hacer más detallados estudios para comprender la dinámica de poblaciones y comunidades.

The crustacean zooplankton in Chilean coastal lagoons has been poorly studied as yet, and the scarce studies available would indicate the presence of low species numbers that vary as a function of the trophic status of the water bodies. The aim of the present study is to make a first characterization of crustaceans in a small shallow coastal lake, using null models, specifically with regard to species co-occurrence and niche overlap. The results revealed that the species associations we found are random, which is due to many species that occur in most or all of the water bodies examined, whereas niche sharing revealed that there is niche segregation due to the absence of competition among the species reported. These results would be in agreement with observations for mountain lakes and lagoons in northern Patagonia, both in Argentina and in Chile, and partially similar to what has been found in Andean shallow wetlands in northern Chile. More and more detailed studies will be necessary for understanding the population and community dynamics in these water bodies.