Open AccessThe Effect of Luteinizing Hormone Releasing Hormone Analog Regime and Stage of Oocyte Maturity for Induced Ovulation of Channel Catfish, Ictalurus punctatus
Author(s) -
Chatakondi Nagaraj G.,
Yant D. Roger,
Kristanto Anang,
UmaliMaceina Gloria M.,
Dunham Rex A.
Publication year - 2011
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.1749-7345.2011.00535.x
Subject(s) - catfish , germinal vesicle , biology , ictalurus , luteinizing hormone , ovulation , endocrinology , hormone , medicine , oocyte , zoology , embryo , fishery , fish <actinopterygii>
This study addresses rapid methods to identify mature channel catfish, Ictalurus punctatus , females for induced spawning with luteinizing hormone releasing hormone analog (LHRHa) and common carp pituitary extract (CPE) and the effects of stage of maturity, hormone dose, season, and cannulation before hormone injection. Hormonal intervention is the most effective method for inducing maturation and spawning in channel catfish × blue catfish, Ictalurus furcatus , hybrids. A total of 80 mature channel catfish were staged for maturity based on secondary sexual characteristics and 20–30 oocytes cannulated to ascertain their maturation stage based on the position of gonadal vesicle. Twenty females were randomly assigned to one of the four hormone regimes (priming + resolving dose): CPE 2 + 8 mg/kg (CPEC); LHRHa 20 + 40 µg/kg (LHRHaL); LHRHa 20 + 60 µg/kg (LHRHaM); and LHRHa 20 + 80 µg/kg (LHRHaH) and a fifth treatment consisted of 20 females selected based on apparent maturity as evidenced by external appearance were injected with CPE, 2 + 8 mg/kg without cannulation (CPEO). Two trials were conducted in early part of the spawning season and two trials in peak season. External methods to identify maturity correlated ( r = 0.63) with that of “germinal vesicle position” method to identify the stage of maturity in females. Mean percent of females that ovulated, hatched, and fry produced per kg body weight did not differ ( P > 0.05) among the five hormone treatments. The mean percent females that ovulated was higher ( P < 0.05) for CPE‐induced females that were identified as “excellent” females based on external examination. The performance of cannulated females did not differ ( P > 0.05) with that of non‐cannulated catfish. The mean egg quality of hormone‐induced females and percent of females ovulated in response to hormone treatment established a weak but significant linear relationship ( Y = 3.85 + 0.008 × ovulation, r 2 = 0.39, P < 0.05).