THE LIFE-HISTORY OF DIKEROGAMMARUS-HAEMOBAPHES (EICHW) (CRUSTACEA, AMPHIPODA) LIVING ON MACROPHYTES IN LAKE BALATON (HUNGARY)

Dikerogammarus haemobaphes appeared and spread in Lake Balaton in the 1950s. Today this species occurs in most of the lake's habitats and pl ays an important role as fish food. This study describes the life hist ory of the amphipod, which lives on a submerged macrophyte, Myriophyll um spicatum, near the Tihany peninsula. Reproduction lasts from May to the end of August. The animals hatched in May-June reproduce in the s ame year, while the summer-autumn generation reproduces the next year. The life span is about one year. Fecundity is highest in June. The re gression of brood sizes (E) on body length in mm (L) is: E = 0.16 L2.2 3 (r = 0.57) The largest biomass of the amphipod was found in November , the lowest at the end of July. In July 1986, the biomass of D. haemo baphes was estimated to 0.1 g animal dry weight/m2 (563 ind./m2) in th e area covered by M. spicatum.