en Biology & physiology Biology & physiology پژوهشي Orginal research papers <p><span style="font-size:11pt"><span style="line-height:102%"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:11.5pt"><span style="line-height:102%"><span new="" roman="" style="font-family:" times=""><span style="color:black">The fertility indices of the African catfish (<i>Clarias gariepinus</i>) milt diluted in different extenders were investigated using four adult males and two adult females. There were four groups with three replicates each, comprising an undiluted fresh milt group (FM; Control) and three groups of different milt extenders: soya beans milk (SM), citrated egg yolk (CEY), and citrated water (CW). Each extended milt group was diluted at a 1:10 ratio and stored at 4 &deg;C for 48 h prior to spawning. After milt extension, the milt pH, sperm motility and viability, and sperm concentration were determined daily for 7 days. The egg fertilization and hatchability rates, fry survival rate, embryo viability rate (at 8 h and 24 h), and fry gross biometry (13 days post-spawning) were evaluated. The results showed no significant difference (<i>p</i><i>>0.05</i>) in the diluted milt pH of the different groups. The sperm viability, motility, and concentration significantly decreased (<i>p</i><0.05) in all groups, although the CEY group had the highest values (<i>p</i><i><0.05</i>) compared to SM and CW treatments. No fertilization was observed in SM treatment. It was concluded that as a milt extender for the African catfish, chilled CW was similar to CEY with respect to fertilization, hatchability, and fry survival rates, while a higher fry body weight was obtained in CW compared to CEY. On the other hand, the chilled SM extender stored for 48 h was not suitable for producing fry due to unsuccessful fertilization.</span></span></span></span></span></span></span></p> African sharptooth catfish, Fertilization, Hatchability, Fry Characteristics, Milt Extenders 893 906 http://jifro.ir/browse.php?a_code=A-10-4603-1&slc_lang=en&sid=1 S.A. Ubah simon.ubah@uniabuja.edu.ng 100319475328460049100 100319475328460049100 No University of Abuja, Nigeria K.O. Abah kennethabah34@yahoo.com 100319475328460049101 100319475328460049101 No University of Abuja, Nigeria A.M. Adetola adejuwonadetola16@gmail.com 100319475328460049102 100319475328460049102 No University of Abuja, Nigeria O.A. Agbonu agbonu.adikpe@uniabuja.edu.ng 100319475328460049103 100319475328460049103 No University of Abuja, Nigeria P.K. Columbus pkcolumbus@yahoo.com 100319475328460049104 100319475328460049104 No University of Abuja, Nigeria S.E. Abalaka seabalaka@yahoo.co.uk 100319475328460049105 100319475328460049105 No University of Abuja, Nigeria C.E. Obudu christopher.obudu@uniabuja.edu.ng 100319475328460049106 100319475328460049106 No University of Abuja, Nigeria C.F. Oguejiofor chike.oguejiofor@unn.edu.ng 100319475328460049107 100319475328460049107 No University of Nigeria, Nsukka E.C. Mbegbu edmund.mbegbu@unn.edu.ng 100319475328460049108 100319475328460049108 Yes University of Nigeria, Nsukka A.Y. Ribadu abdullahi.ribadu@uniabuja.edu.ng 100319475328460049109 100319475328460049109 No University of Abuja, Nigeria