Open AccessComparative Growth of Diploid and Triploid Asian Catfish Clarias macrocephalus in Thailand
Author(s) -
Fast Arlo W.,
Pewnim Thanit,
Keawtabtim Rathaya,
Saijit Rungarun,
Te Franklin T.,
Vejaratpimol Renu
Publication year - 1995
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.1995.tb00834.x
Subject(s) - biology , catfish , stocking , fish <actinopterygii> , ploidy , zoology , human fertilization , fishery , larva , clarias , anatomy , botany , genetics , gene
Wild caught Asian catfish were spawned manually following HCG injection, and a portion of the eggs were subjected to cold‐shock at 4 C for 15 min within 2‐min post‐fertilization. Nuclear diameter measurements of cold‐shocked fish revealed that 96% were triploids (3N), while non‐shocked fish were all diploids (2N). During larval and fry culture (first 26 d), triploid fish mortality was =50%, while diploid mortality was =25%. Following 8‐mo culture in tanks at three stocking densities, triploid fish survival was significantly greater ( P < 0.05), than diploids, with 84.0% and 57.3%, respectively. Triploid live weight was also significantly greater than diploids, with 69.2 and 45.9 g averages, respectively. Ninety‐two percent of diploids had welldeveloped gonads after 8 mo; whereas none of the triploids had mature gonads. Gonads were undifferentiated with 31% of the triploids. These sexually undifferentiated fish had greater growth rates than male or female triploids, and greater growth than all diploids. Carcass weight (gutted) of triploids was 95.8% of live weight, compared with 92.5% for diploids. Lastly, triploids had very few deformities compared with diploids, with 1.3% and 17.6%, respectively. Deformities included curved spines, and humped backs just posterior of the head.