TITLE:
Morphometry, Evidence of Head-Body Length Allometry in Broodstock from Lake Kivu, and Physicochemical Dynamics of Rearing Environments for Optimizing Larval Survival in the African Catfish (Clarias gariepinus)
AUTHORS:
Elie Namegabe Bacirheba, Désiré Akonkwa Balagizi, Jean-Berckmans Bahananga Muhigwa, Guillain Andanga Machumu, Gabriel Mukabo Okito
KEYWORDS:
Clarias gariepinus, Morphometry, Allometry, Broodstock, Water Quality, Larval Survival
JOURNAL NAME:
Open Journal of Marine Science,
Vol.16 No.4,
September
10,
2026
ABSTRACT: This study examines broodstock morphometry and hatchery water quality to improve larval performance in Clarias gariepinus. It combines morphometric measurements, short-term broodstock conditioning, and physicochemical monitoring during incubation and larval rearing. Sexual dimorphism in broodstock and stable rearing conditions are reported, and it is argued that these factors support better larval survival. Morphometric analyses revealed marked sexual dimorphism: females were heavier and longer (616.67 g; 40.28 cm) than males (582.17 g; 37.72 cm), with a strong correlation between female weight and fecundity. Negative head allometry was observed in males, while females exhibited positive head allometry, suggesting direct implications for growth and broodstock selection. Physicochemical monitoring of the water in the hatchery revealed good stability: an average temperature of 27.3˚C, neutral pH (6.95), high dissolved oxygen (6.42 mg/L), and near-zero levels of ammonia and nitrites. These conditions reduced larval mortality risk, which is often linked to thermal and chemical fluctuations. Statistical correlations confirmed the inverse relationship between temperature and dissolved oxygen, confirming effective control of the rearing system. The results demonstrate that the combination of rigorous morphometric selection of broodstock and strict control of water quality constitutes an effective approach to improving larval survival and strengthening Clarias gariepinus aquaculture.