Laserfiche WebLink
converted back into actual densities because of small sample size and a negative <br />binomial distribution (Elliot 1977). <br />RESULTS <br />en ho <br />Nematoda and the naupliar stages of copepods were the most abundant groups <br />in the benthos (Table 1). The densities of the major benthic taxa are within the range <br />of previously reported densities except for microcrustaceans (Mabey 1993, Wolz <br />1993). Both benthic copepods and cladocerans were found at higher densities than <br />during a previous study (Mabey 1993), and were more comparable to densities <br />reported in that study for seasonally inundated wetland areas near the river. At least <br />four species of cyclopoid copepods were present in the backwater benthos: <br />Eugyclop-a speratusi- Eucyclops priono horus, Acanthocyclops vernalis, and Diacyclops <br />bicuspidatus, although A. vernalis and D. bicus ids atus are in low numbers. At least 10 <br />chironomid genera were collected in the benthos over the period of our study: <br />Chironomus, Glyptotendipes, Cryptochironomus, Polypedilum, Stempellinella. <br />Nimbocera, Tan arsus, Lenziella, Tanypus, and Procladius. Only Chironomus and <br />Tanypus were abundant. We found two species of cladocerans present in the benthos <br />during our study: Ilyocryptus sordidus, and Macrothrix I is rni (Table 1). <br />Densities of naupliar and copepodite copepods were significantly lower (a = <br />0.05) in the closed treatments than in control areas (Table 2), while the chironomid <br />genus Tanypus was significantly higher (a = 0.05) in the closed treatments. The <br />8