Open AccessTRIPLOIDY IN CHANNEL CATFISH
Author(s) -
Chrisman C. Larry,
Wolters William R.,
Libey George S.
Publication year - 1983
Publication title -
journal of the world mariculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0735-0147
DOI - 10.1111/j.1749-7345.1983.tb00084.x
Subject(s) - biology , catfish , ictalurus , hatching , zoology , human fertilization , ploidy , sperm , insemination , fish <actinopterygii> , andrology , fishery , anatomy , botany , genetics , medicine , gene
Triploidy was induced in channel catfish ( Ictalurus punctatus ) by hand stripping eggs from gravid females, fertilization with minced testes from donor males, and cold shocking the eggs at 5°C for one hour beginning 5 minutes post‐fertilization. Hatching success of eggs cold shocked for one hour was 79% compared to 89% in controls. Cold shocks longer than one hour caused 100% mortality. Cytogenetic observations through lymphocyte cultures and direct processing of mitotic cells from kidney tissue confirmed that all controls were diploid (2n=58 chromosomes) and 100% of the one‐hour cold shocked treatment group were triploid (3n=87 chromosomes). Full sibling diploid and triploid channel catfish were reared in round 870‐liter fiberglass tanks indoors with water supply, filtration, and disease treatment common to both tanks. All fish were fed 4 times daily to satiation for the first month, twice daily to 8 months, then once daily thereafter with appropriately sized trout rations (35% protein). Triploids were significantly heavier at 8 months of age and older stages than the diploids (92.9±0.98 g vs 87.8±1.09 g at 8 months) and converted feed more efficiently (1.19 kg feed per kg of gain in triploids vs 1.3 in diploids). Histological analysis of ovaries and testes from 54 fish representing both ploidy levels confirmed the almost complete lack of sexual development characteristic of many triploid organisms.