Hand-stripping of semen and semen quality after maturational hormone treatments, in African catfish Clarias gariepinus

In the hatchery-bred African catfish, Clarias gariepinus, spontaneous semen release does not occur and hand-stripping is practically impossible. This reproductive dysfunction may be due to a lack of a pre-spawning gonadotropin (luteinizing hormone—LH) surge. To test this hypothesis, the effects of hormones that increase plasma LH levels were analyzed. Mammalian gonadotropin releasing hormone analogue (mGnRHa), mGnRHa plus pimozide, a dopamine antagonist (mGnRHa-PIM), ovaprim (salmon GnRHa plus domperidone, a dopamine antagonist), carp pituitary suspension (carp-PS), Clarias pituitary suspension and combinations of carp-PS and ovaprim were tested. Stripped fluid, when present, was compared to intratesticular semen, 12 or 24 h after injection (latency time). Plasma LH levels increased ( P