Non-invasive Method for Collection of Clarias magur Spermatozoa for Breeding

Abstract

ABSTRACT: Induced spawning is more inefficient in Clarias magur than in other fish species such as cyprinids and salmonids. Ovulation can be induced in the female C. magur by using pituitary extract or synthetic hormones. However, milt from the male C. magur cannot be obtained by hand stripping because the volume of seminal fluid in the testes is extremely low. Notably, similar problems are observed in other male catfishes such as C. gariepinus and C. lazera. Because milt from the males cannot be obtained for use in artificial fertilization of eggs, males are invariably sacrificed, and the testicular tissue is excised and macerated to obtain spermatozoa. • We developed an alternative approach that allowed harvesting of C. magur spermatozoa through surgery for artificial fertilization without sacrificing male fish. • The surgically obtained spermatozoa were used to inseminate C. magur eggs; the cross resulted in healthy progeny with a fertilization rate of 80%–98% and hatching of up to 85% of fertilized embryos; similar to those obtained using the conventional sacrificial approach (hatching percentage range of 45%–85%) [1]. • This indicated the viability of partial surgical harvest of testicular tissue in seed production in C. magur for aquaculture without sacrificing male fish.

Keywords

• Catfish
• Surgery
• Spermatozoa
• Breeding
• Aquaculture