CROSSBREEDING OF Pangasianodon hypophthalmus (SAUVAGE, 1878) AND Pangasius nasutus (BLEEKER, 1863) AND THEIR LARVAL DEVELOPMENT

This study was conducted to determine the feasibility of producing hybrid catfish through reciprocal crossbreeding between Pangasianodon hypophthalmus (Sauvage) female and Pangasius nasutus (Bleeker) male (HN) and between P. hypophythalmus male and P. nasutus female (NH). Two control groups with homogenous breeding of P. hypophthalmus (HH) and P. nasutus (NN) were also conducted. The results of HN showed better breeding performance with an average value of fertilisation (81.17%), hatching (83.06%) and deformation rate (8.51%) compared to NH with 60.96, 54.61 and 14.68%, respectively, for the same parameters. For the control HH, fertilisation, hatching and deformation rate were 93.18, 89.73 and 4.14%, respectively, while, for NN, 76.83, 68.26 and 7.16%, respectively. Fertilised eggs of HN (1.08-1.10 mm) were smaller than NH (1.80-1.90 mm), with no significant difference with their parental fishes (HH and NN). The incubation time of HN (20-26 hours) was shorter than that of NH (30-36 hours) after fertilisation. The incubation times of HH and NN were: 18-24 and 36-40 hours, respectively. Newly-hatched larvae of HN were: 3.92±0.04 mm in total length and 0.22±0.02 mg in weight, while, NH were 5.69±0.08 mm and 1.76±0.07 mg, respectively. Newly-hatched larvae for control (HH) was 3.47±0.12 mm long (TL) and 0.22±0.03 mg weight, while for NN was 5.79±0.26 mm and 2.25±0.59 mg, respectively. Thus, it could be concluded that cross-bred HN showed relatively better performance in the cross-breeding programme.