Reproductive Biology of Albacore Tuna (Thunnus alalunga) in the Western Indian Ocean
|Author(s)||Dhurmeea Zahirah1, 2, Zudaire Iker2, 3, Chassot Emmanuel2, 4, Cedras Maria4, Nikolic Natacha5, Bourjea Jerome6, West Wendy7, Appadoo Chandani8, Bodin Nathalie2, 4|
|Affiliation(s)||1 : Univ Mauritius, Fac Sci, Dept Biosci, Reduit, Mauritius.
2 : IRD Res Unit MARine Biodivers Exploitat & Conserv, Victoria, Mahe, Seychelles.
3 : Basque Fdn Sci, Ikerbasque, Bilbao, Spain.
4 : SFA, Victoria, Mahe, Seychelles.
5 : Ifremer DOI Reunion, Le Port, Reunion.
6 : Ifremer Res Unit MARine Biodivers Exploitat & Con, Sete, France.
7 : DAFF, Cape Town, South Africa.
8 : Univ Mauritius, Dept Marine & Ocean Sci, Fisheries & Mariculture, Fac Ocean Studies, Reduit, Mauritius.
|Source||Plos One (1932-6203) (Public Library Science), 2016-12 , Vol. 11 , N. 12 , P. e0168605 (1-22)|
|WOS© Times Cited||4|
|Abstract||The reproductive biology of albacore tuna, Thunnus alalunga, in the western Indian Ocean was examined through analysis of the sex ratio, spawning season, length-at-maturity (L50), spawning frequency and fecundity. From 2013 to 2015, a total of 923 female and 867 male albacore were sampled. A bias in sex ratio was found in favor of females with fork length (LF) < 100 cm. Using histological analyses and gonadosomatic index, spawning was found to occur between 10°S and 30°S, mainly to the east of Madagascar from October to January. Large females contributed more to reproduction through their longer spawning period compared to small individuals. The L50 (mean ± standard error) of female albacore was estimated at 85.3 ± 0.7 cm LF. Albacore spawn on average every 2.2 days within the spawning region and spawning months, from November to January. Batch fecundity ranged between 0.26 and 2.09 million oocytes and the relative batch fecundity (mean ± standard deviation) was estimated at 53.4 ± 23.2 oocytes g-1 of somatic-gutted weight. The study provides new information on the reproductive development and classification of albacore in the western Indian Ocean. The reproductive parameters will reduce uncertainty in current stock assessment models which will eventually assist the fishery to be sustainable for future generations.|