First record of the genus Clunio (Diptera: Chironomidae) associated with the coral communities at Islas Marietas, Mexico

Abstract

Chironomids are common dipterans found in aquatic ecosystems. These organisms are ecologically importantas consumers of particulate organic matter and they are consumed by fish, insects and birds. Most of the larvae arefrom fresh-water, but Clunio is exclusively marine and frequently associated with rocky shores and hard substrates.Six bimonthly samplings were conducted at Islas Marietas National Park during March 2011 to February 2012, usingcalcareous skeleton as a recruitment substrate. We found 89 larvae and 1 imago of the genus Clunio. The larvaeshowed a mean density of 0.015 ind·cm-2, with a maximum value of 0.033 ind·cm-2 during June-July, coinciding withthe period with the highest sea surface temperature registered. Simultaneously, the micro-substrate adhered to thecoral skeleton was identified and quantified; however, no relationship between the type of substrate and larval densitywas found (R= 0.61, p= 0.197). This study is the first record of Clunio, as well as the annual changes in abundanceat the Mexican Pacific.