Influence of tropical seasonal changes on oocyte diameter, responses to hormonal induction and hatching quality in two strains of the catfish, Heterobranchus longifilis Val. (Clariidae)

Abstract

A comparison was made between the oocyte diameter, pseudo‐absolute fecundity (PAF) and egg quality of two strains of the catfish, Heterobranchus longifilis, maintained in outdoor ponds under a tropical highland climate in Cameroon. The results indicated that circannual endogenous rhythms for ovarian recrudescence and regression are absent in H. longifilis, irrespective of breeding history, age and strain. There appeared to be a possible slight adverse effect of climate (dry season) on reproductive performance of both strains. Oocyte diameter and PAF increased with increasing fish weight when data from both strains were combined, indicating that the two strains may exhibit the same reproductive performance. Viable eggs were obtained all year round after hormonal induction. It is concluded that for propagation of H. longifilis in tropical African countries, broodfish could be maintained in outdoor earthen fish ponds with proper feeding.

Parent–egg–progeny Relationships in Teleost Fishes: An Energetics Perspective

“…(Tamada and Iwata, 2005), Salvelinus fontinalis, arctic charr (Salvelinus alpinus), Danube salmon (Hucho hucho) and grayling (Thymallus thymallus) (Purtscher and Humpesch, 2006). In a tropical catfish vundu (Heterobranchus longifilis) heavier females poduced larger oocytes (Nguenga et al, 2004). At the inter-population level a positive, highly significant correlation (p < 0:01) between egg diameter and female size (log standard length) was found for 48 populations belonging to 25 freshwater European fish (Vila-Gispert and Moreno-Amich, 2002).…”

Artificial spawning of African catfish Heterobranchus longifilis: differences between the effects on reproduction in females treated with carp pituitary homogenate or Ovopel

“…In H . longifilis , HCG has chiefly been used for ovulation induction (Legendre 1986; Legendre & Otémé 1995; Nguenga et al 2000, 2004a, b). The comparison of reproduction results in this fish species using HCG in ovulation stimulation with the results recorded after the application of two doses of Ovopel (1/5+1 pellet kg −1 ) show that better effects can be obtained with Ovopel (Adamek & Brzuska 2005).…”

“…In later years the results of ovulation stimulation with this preparation in H . longifilis were also reported (Legendre et al 1992; Nguenga, Teugels, Legendre & Ollevier 2004a, b; Adamek & Brzuska 2005). The results of H. longifilis reproduction in controlled conditions with the use of ovulation stimulator Ovopel ( d ‐Ala 6 , Pro 9 NEt–mGnRH and water soluble dopamine receptor antagonist metoclopramide; Horváth, Szabó & Burke 1997) applied at one or two doses (1 or 1/5+1 pellet kg −1 ) were reported by Adamek and Brzuska (2005).…”

Intra-specific hybridization and larval performance of two strains of wild African catfish Clarias gariepinus (Burchell, 1822) (Siluriformes: Clariidae) from Cameroon

“…For both stocks, males and females were stocked separately. Aller Claria Float 6.00 mm feed (40% crude protein, 12% crude fat, 32% NFE, 3.1% Fibre, 5.1% Ash) was administered daily; at the rate of 1% wet body weight (Nguenga et al, 2004). Feeding was ocassionally supplemented with local fishery by-catch predominantly of small clupeids of the species Pellonula miri (Njanja motto) and Ethmalosa fimbriata (Bonga) at 3% wet body weight.…”