• Title/Summary/Keyword: Sexual maturation

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Optimizing selection of sexually mature Barbus altianalis for induced spawning: determination of size at sexual maturity of populations from Lake Edward and Upper Victoria Nile in Uganda

  • Aruho, Cassius;Ddungu, Richard;Nkalubo, Winnie;Ondhoro, Constantine Chobet;Bugenyi, Fredrick;Rutaisire, Justus
    • Fisheries and Aquatic Sciences
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    • v.21 no.11
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    • pp.34.1-34.13
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    • 2018

  • Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.

  • https://doi.org/10.1186/s41240-018-0110-3 인용 PDF

Effect of Temperature on Induced Sexual Maturation of the Hard Clam, Meretrix petechiails (Lamarck) Broodstock (말백합, Meretrix petechiails (Lamarck) 어미의 사육수온에 따른 성 성숙 유도)

  • Kim, Byoung-Hak;Moon, Tae-Seok;Park, Ki-Yeol;Jin, Young-Guk;Shin, Yun-Kyung
    • The Korean Journal of Malacology
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    • v.25 no.2
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    • pp.113-119
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    • 2009

  • Artificial induction of maturation by heating of the hard clam, Meretrix petechiails (Lamarck) broodstock was investigated from 25 May to 30 June in 2008. We experimented maturation by keeping the breeding water temperature at 20, 25 and $30^{\circ}C$ and as the natural water temperature and found the following results. In case of the female, maturation was the quickest in the experiment group of $30^{\circ}C$ and the maturation tended to be slower as the water temperature was lower. The similar trend was displayed among the male. At experiment completion, maturation induction rate was found to be the highest at 46.0% in the experiment group of $30^{\circ}C$ followed by 35.0% in the experiment group of $15^{\circ}C$, 18.0% in the experiment group of natural water temperature and 12.0% in the experiment group of $20^{\circ}C$. During the period of the experiment, the survival rate was of 90% or more in all groups.

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