ホソワレカラCaprella danilevskii Czerniavski (甲殻綱, 端脚目) の生活史 (予報)
1988 年 1988 巻 32 号 p. 37-41
詳細
1988 年 1988 巻 32 号 p. 37-41
TAKEUCHI, Ichiro and Reijiro HIRANO (Department of Fisheries, Faculty of Agriculture, University of Tokyo). 1988. A preliminary report on the life-history of Caprella danilevskii Czerniavski (Crustacea, Amphipoda) reared in the laboratory Benthos Research (Bull. Jap. Assoc. Benthology), 32 : 37-41.
Caprella danilevskii Czerniavski was successfully reared two generations under laboratory conditions. This report presents an outline of the life cycle. Animals were maintained in pairs or four individuals in petri dishes (5.7 cm in diameter and 5.6 cm in depth) containing filtered seawater at 20°C. Colony of Cylindrotheca closterium (Ehrenberg) Reimann et Lewin was supplied as a source of food, and the red alga Gelidium amansii (Lamouroux) Lamouroux was given as a site of attachment for caprellids.
Juveniles, 1.5 mm in body length, released from brood pouch were prescribed as the instar I. Following instars were decided by affirmation of molts. They molted successively at 2.5-6.5 days intervals. Body length of males increased exponentially, and that of female represented a sigmoid curve. Body length of instar VII was 6.5 mm in male and 5.5 mm in female, and that of X was 10.9 mm in male and 7.0 mm in female. Average life span was 46.5 days in male (n=15) and 46.0 days in female (n=8). At the age of 20.8 days, females reached instar VII and produced first eggs, and juveniles were released 5.1 days later. Females reproduced eggs 5.4 times successively at about 5 days intervals, and the total number of offspring was 69.4 individuals per female.
