open access
메뉴
open access
메뉴
ISSN : 1225-3480
Reproductive cycle with the gonadal phases, first sexual maturity, artificial spawning amount by the size and spawning interval of the hard clam, Meretrix lusoria were investigated by histological observations and morphometric data by artificial spawning induction. Meretrix lusoria is dioecious and oviparous. The reproductive cycle of this species can be classified into five successive stages: early active stage (January to March), late active stage (February to May), ripe stage (April to August), partially spawned stage (June to September), and spent/inactive stage (September to February). The spawning period was from June to September, and the main spawning occurred between July and August when the seawater temperature exceeds over <TEX>$20^{\circ}C$</TEX>. Percentage of first sexual maturity of female and male clams ranging from 40.0 to 45.0 mm in shell length was over 50%, and all clams over 50.0 mm in shell length sexually matured. Female and male clams ranging from 40.0 to 45.0 mm in shell length are considered to be two years old. Therefore, we assume that the hard clams of both sexes begin reproduction from two years of age. The mean number of the spawned eggs increased with the increase of size (shell length) classes. In case of artificial spawning induction, the number of spawned eggs from the clams of a sized class was gradually decreased with the increase of the number of the spawning frequencies (the first, second, and third spawnings). In the experiments of artificial spawning induction during the spawning season, the interval of each spawning was estimated to be 15-18 days (average 17 days).
(1984) Reproductive energy metabolism in the bay scallop University of South Florida,
(198318-26) Reproductive effort and value in different populations of the marine mussel,
(1974) Studies on the artificial fertilization and development of Meretrix lusoria,
(1975) Comparative studies on the early embryonic development and growth of Meretrix lusoria and Cyclina sinensis,
(1981) Basic studies for the production of the hard clam Meretrix lusoria Bulletin of the Fisheries Research Development Agency,
(1997) Ultrastructural study of germ cell development and reproductive cycle of the hen clam,
(2000) Gametogenesis and sexual maturation of the surf clam Mactra veneriformis on the west coast of Korea,
(2002) and deposition of the egg capsules of the female purple shell,
(2005) Reproductive biology of the female Manila clam on the west coast of Korea,
(1994) Comparative studies on the embryonic development and the growth of larvae of eight bivalve species National Fisheries University of Pusan,
(1999) Seasonal variation of the primary productivity in the vicinity of Chulpo Sea area, Kunsan National University
(2005) A study on reproductive ecology of the hard clam on the west coast of Korea, Kunsan National University
(1993) Coloured shells of Korea, Academy Publishing Company
(1997) Histological studies on the gametogenesis and reproductive cycle of the hard clam,
(1959) Ecological studies in the natural population of a clam with special reference to seasonal variations in the size and structure of population and to individual growth Biological Journal of Okayama University,
(1973) A stochastic model of the temporal aspect of breeding strategies,
(1974) Biology and distribution of the toheroa,
(1966) Temperature effects in reproduction of the bay scallop,
(1968) Relationship among food temperature and gonad development of the bay scallop,
(1979) Reproduction of Marine Invertebrates, Academic Press
(1954) Spawning season of important bivalves in Ariake Bay Bulletin of Japanese Society Science Fisheries,
(1994) Relationship of size to gonadal maturation and spawning in artificially conditioned Manila clams,
(1953) Studies on larvae and young shells of industrial bivalves in Japan,