Open AccessGametogenesis in Pubescent Heterobranchus longifilis (Teleostei: Clariidae) (Val. 1840) Attaining Puberty Under Artificial Conditions; and Under Rainy and Dry Season Conditions, in Tropical Earthen Ponds
Author(s) -
CO Ofor
Publication year - 2005
Publication title -
asian fisheries science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.275
H-Index - 7
eISSN - 2073-3720
pISSN - 0116-6514
DOI - 10.33997/j.afs.2005.18.2.006
Subject(s) - biology , sexual maturity , wet season , dry season , gonadosomatic index , gametogenesis , zoology , aquaculture , development of the gonads , ecology , fishery , fecundity , fish <actinopterygii> , population , cryopreservation , embryo , demography , sociology
Three groups of Heterobranchus longifilis attained puberty under three environmental conditions. In experiment 1, 23 fish (10 males, 13 females) were raised in the rainy season, (group 1). In experiment 2, 90 fish (39 males, 51 females) were raised in a recirculation system (group 2). In experiment 3, 160 fish (73 males, 87 females) were raised in the dry season (group 3 ). Groups 1 and 3 were raised in outdoor earthen ponds. Gametogenesis in the groups was studied using histology and gonadosomatic index. Oocytes maturation commenced at 9½ months in all groups and lasted 67 days in group 1, and about 130 days in groups 2 and 3. Sexual maturity occurred at 352, 427, and 425 days respectively in groups 1, 2 and 3. It seems that the key point in ovarian maturation in pubescent Heterobranchus longifilis is 9½ months, with further oogenesis being influenced by rainfall. The time spent from here to sexual maturity onset may be shortened if it falls within the rainy season. The period may run its full course if it falls within the dry season, or the rearing environment is indoor. The application of these observations in the aquaculture of the species is discussed.