Springer Online Journal Archives 1860-2000
Abstract A study of the vertical distribution of all instars of chironomid larvae was carried out in the littoral zone of a lake in southwest England over a period of 14 months. Samples were collected every month by using a 44 mm (i.d.) piston core sampler. Each core sample was sectioned at 1 cm intervals and preserved immediately after collection. The density of larvae in the study area varied from a low of 16,368 larvae m−2 in August 1989 to maximum values of 106,249 and 129,954 larvae m−2 in June 1989 and May 1990, respectively. During spring and early summer, first instar larvae comprised approximately half of the larval population. No significant differences were found in seasonal vertical distribution of the chironomid larvae. Over 85% of the larval population inhabited the top 6 cm of the sediment, with the first and second instar larvae of all taxa most abundant in the top 1 cm section.
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