GENERAL AND COMPARATIVE ENDOCRINOLOGY 81, 343-348 (1991) Profiles of Progesterone- and Estradiol-like Substances in the Hemolymph of Female Panda/us kessleri during an Annual Reproductive Cycle EMILIA T. QUINITIO,*~’ KOHEI YAMAUCHI ,* AKIHIKO HARA,S AND AKIRA FUJI* *Department of Biology, Faculty of Fisheries, Hokkaido University, Hakodate 041 Japan; fAquaculture Department, Southeast Asian Fisheries Development Center, Tigbauan, Iloilo 5021, Philippines; and SNanae Fish Culture Experimental Station, Faculty of Fisheries, Hokkaido University, Sakura, Nanae. Kameda-Gun, Hokkaido 041-l I, Japan Accepted February 14, 1990 The changes in GSI and HSI of Panda/us kessleri were monitored during an annual reproductive cycle. GSI reached a peak when ovaries were composed of yolky oocytes and decreased sharply during the spawning season. HSI followed a similar pattern. The changes in the concentrations of progesterone- and estradiol-178~like substances in the hemolypmh were also investigated. Progesterone levels increased at the onset of vitellogenesis and decreased during vitellogenesis. In contrast, estradiol concentrations rose during the peak of vitellogenesis and dropped after the release of mature eggs from the gonad. 0 1991 Academic Press, Inc. Vertebrate-like hormones have been de- tected in various species of marine inverte- brates (Sandor, 1980; Voogt et al., 1984; De Loof and De Clerk, 1986). Ollevier et al. (1986) identified cholesterol, pregnenolone, 17a-hydroxypregnenolone, 6@hydroxy- progesterone, and testosterone in the he- molymph of adult female crayfish Astacus leptodactylus. Estrogenic activity, i.e., estradiol-17B, has been identified in the eggs of lobster Homarus americanus (Lisk, 1961). The presence of estrogens was also confirmed in the ovary of the shrimp Paru- penaeus fissurus by Jeng et al. (1978). Couch et al. (1987) observed that proges- terone and estradiol-17B concentrations in the mandibular organ, green gland, hepato- pancreas, ovary, and serum of H. america- nus change in relation to ovarian develop- ment. More recently, Van Beek and De Loof (1988) determined radioimmunologi- tally six Czl, Ci9, and C,s steroids in body extracts of female Artemiu during the re- ’ To whom all correspondence should be addressed. productive cycle. However, reports on the changes of steroid concentrations in the he- molymph of crustaceans during the repro- ductive cycle including the possible roles of these steroids in vitellogenesis are very lim- ited. In this study, we monitored the changes in progesterone and estradiol-17B concen- trations in the hemolymph of the female hermaphrodite shrimp, Pandalus kessleri during an annual reproductive cycle. The possible roles of these steroids during vitel- logenesis are also discussed. MATERIALS AND METHODS Samples Samples of P. kessleri were caught in Notsuke Bay, east of Hokkaido, and transferred to Hokkaido Insti- tute of Mariculture at Shikabe, Hokkaido. Sex was determined by examining the secondary sexual char- acters of the first and second pleopods following Kash- iwagi (1974) and confirmed later by histological exam- inations. Females weighing 8.1-23.8 g with carapace length ranging from 2.6 to 3.9 cm were used in this study. Hemolymph samples were drawn from the ab- 343 0016~6480/91 $150 Copyright 0 1991 by Academic Press, Inc. All rights of reproduction in any form reserved.