Age, growth and reproductive biology of Lethrinops gossei burgess & axelrod– (Teleostei: cichlidae) in the south east arm of Lake Malawi

Abstract: 
Life history traits of Lethrinops gossei from south east arm of Lake Malawi were studied. Validation of age was done by using analysis of marginal increment and length frequency distribution. It was assumed that a single opaque ring was laid down annually in the otoliths. The greatest age estimated was 6+ years (175 ± 1.14 mm total mean length (TL). Growth was best described by the von Bertalanffy growth model as Lt = 150.06(1 – e-0.27(t + 1.94)) r2 = 0.95. The mean size at maturity for females was 135.95mm TL and 104.05 mm standard length (SL). Age at-50% maturity was estimated at 2.14 years. The mean value for total mortality (Z) from the catch curve analysis was estimated at 0.63 year-1, natural mortality (M) was 0.38 year1, fishing mortality (F) calculated (F = Z – M) was 0.25 year-1 and the exploitation rate was 0.40.
Les traits d’histoire de la vie de Lethrinops gossei du bras Sud-Est du lac Malawi ont été étudiés. La validation d’âge a été faite en utilisant l’analyse de l’accroissement marginal et de la distribution des fréquences de longueur. On a supposé qu’un anneau opaque unique a été fixé chaque année dans les otolithes. Le plus grand âge estimé est de 6 ans (175 ± 1,14 mm de longueur totale moyenne (TL). La croissance a été mieux décrite par le modèle de croissance de von Bertalanffy Lt = 150.06(1 – e-0.27(t + 1.94)) r2 = 0.95. La taille moyenne à la maturité pour les femelles a été 135.95mm de TL et 104,05 mm de longueur standard (SL). L’âge à 50% de maturité a été estimé à 2,14 ans. La valeur moyenne de la mortalité totale (Z) à partir de l’analyse de la courbe de capture a été estimée à 0,63 par an. La mortalité naturelle (M) était de 0,38 par an. La mortalité due à la pêche (F), calculée comme F = Z – M, était de 0,25 par an et le taux d’exploitation était de 0,40.
Language: 
Date of publication: 
2010
Country: 
Region Focus: 
Southern Africa
University/affiliation: 
Collection: 
RUFORUM Conferences and Workshops
Licence conditions: 
Open Access
Access restriction: 
Form: 
Printed resource
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ISSN: 
E_ISSN: 
Edition: 
Extent: 
1277-1279
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About the RUFORUM 2010 Biennal Conference
"The 2010 RUFORUM Biennial Conference was the second in the series. The main objective of the Biennial conferences is to provide a platform for agricultural research for development stakeholders in Africa and beyond to actively exchange findings and experiences, while at the same time learning lessons towards improving performance of the agricultural sector and ultimately people’s livelihoods. The biennial conference is RUFORUM’s most comprehensive meeting for the diversity of stakeholders in agriculture. It is especially dedicated to graduate students and their supervisors, grantees in RUFORUM member universities and alumni. It is a platform for peer review, quality control, mentorship, networking and shared learning. This record contains an extended abstract accepted under the theme of Aqua Culture and Fisheries"