engleski

Chironomid larvae assemblages’ structure in association with two submerged macrophyte species

Spatial and temporal trends of a phytophylous chironomid community on the submerged plant species Myriophyllum spicatum L. and Ceratophyllum demersum L. were studied at three sites in a floodplain lake (Lake Sakadaš, Kopački Rit Nature Park, Croatia) during summer 2004. Analysis of functional feeding groups and the influence of environmental parameters on Chironomidae larvae assemblages were also conducted. Chironomid community was very abundant and the recorded larvae belonged to three subfamilies: Chironominae (Chironomini and Tanytarsini), Orthocladiinae and Tanypodinae. In both species stands larvae of Cricotopus sylvestris gr. and Endochironomus albipennis type dominated. However, the total abundance of E. albipennis type was seven times greater in association with C. demersum and C. sylvestris gr. had abundance 1.5 times greater in M. spicatum stands. Other representatives of Chironominae were more abundant in C. demersum stands, such as Paratanytarsus sp., Glyptotendipes pallens type, Polypedilum sordens type and Parachironomus varus type. Most larvae in the community on M. spicatum belonged to grazers while active filterers and grazers were most abundant in C. demersum stands. ANOSIM indicated statistically important differences between July and September based on the chironomid abundance, and there were no differences between the sampling stations. According to BIO-ENV analysis, environmental variables with highest influences on chironomid community structure, for both plant species, were: water temperature, depth and oxygen concentration, with Secchi depth and chlorophyll a concentration in a lesser extent.

Chironomidae; phytophylous communities

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