CHANGES IN REPRODUCTIVE MORPHOLOGY AND PHYSIOLOGY OBSERVED IN THE AMPHIPOD CRUSTACEAN, MELITA-NITIDA SMITH, MAINTAINED IN THE LABORATORY ONPOLLUTED ESTUARINE SEDIMENTS

An earlier study showed that the amphipod crustacean Melita nitida Smi th maintained on sediments dosed with waste crankcase oil developed ph ysiological and morphological abnormalities. Most notably, mature fema les developed abnormal setae along the edges of their brood plates. Th e present study was conducted to determine whether similar abnormaliti es might be induced in animals maintained on polluted field sediments containing petroleum by-products among other toxic substances. In the laboratory, heterosexual pairs were maintained on three sediments take n from Jamaica Bay (New York) plus one control sediment and one toxic substratum (Ulva lactuca (L.) thalli). The results mirrored the result s of the previous study. Under controlled conditions brood production was reduced on polluted sediments by as much as 57% and a greater prop ortion of females maintained on polluted sediments developed abnormal brood plate setae. In contrast, while brood production was lower in fe males exposed to U. lactuca than on the control sediment, there was no significant difference between the two groups in the number of female s that developed abnormal brood plates. (C) 1997 Elsevier Science B.V.