Reproductive biology of the anchovy (Stolephorus commersonnii, Lacepède, 1803) and spotted sardine (Amblygaster sirm, Walbaum, 1792) from Tanga Region, Tanzania

  • Joseph S. Sululu Tanzania Fisheries Research Institute- Dar es Salaam Centre, P.O. Box 78850, Dar es Salaam, Tanzania
  • Albogast T. Kamukuru Department of Aquatic Sciences and Fisheries Technology, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania
  • Baraka C. Sekadende Tanzania Fisheries Research Institute- Dar es Salaam Centre, P.O. Box 78850, Dar es Salaam, Tanzania
  • Shigalla B. Mahongo Tanzania Fisheries Research Institute, Institute Headquarters, P.O. Box 9750 Dar es Salaam, Tanzania.
  • Mathias M. Igulu WIOMSA Mizingani Street, P.O. Box 3298, Zanzibar, Tanzania
Keywords: Anchovies, Clupeids, Reproduction, Tanga, Ringnet fishery

Abstract

The present study investigated the reproductive biology of Stolephorus commersonnii and Amblygaster sirm at two landing sites in Tanga on the northern coast of Tanzania. Fish samples were collected on a monthly basis from ringnets operated by artisanal fishers in the nearby coastal waters. Spawning seasons were determined using gonadosomatic index (GSI) and gonadal maturity stages. The size at first maturity was 57.7 mm and 66.2 mm total length for male and female S. commersonnii respectively. Male and female A. sirm were estimated to attain first maturity at 147.7 mm and 169.2 mm respectively. The spawning seasons of both species were protracted. S. commersonnii demonstrated a year round spawning cycle with peaks in August, October and January. The peak spawning season for male and female A. sirm was recorded in August and September respectively. Both species exhibited skewed size-dependent sex ratios with females predominating in the larger size classes. A. sirm had a higher fecundity rate with a maximum of 96,500 eggs in the largest female fish of 258 mm as compared to S. commersonnii (10,055 eggs) in the largest fish of 98 mm. The mean (±SE) total fecundity of S. comersonnii and A. sirm was 5,134.7 ± 136.9 eggs, and 47,029.03 ± 1,435.13 eggs in females of sizes 68 mm to 98 mm and 170 mm to 258 mm respectively.

Author Biographies

Joseph S. Sululu, Tanzania Fisheries Research Institute- Dar es Salaam Centre, P.O. Box 78850, Dar es Salaam, Tanzania

Fisheries research Institute, Research officer

Albogast T. Kamukuru, Department of Aquatic Sciences and Fisheries Technology, University of Dar es Salaam, P.O. Box 35064, Dar es Salaam, Tanzania

University of Dar Es Salaam, Lecturer

Baraka C. Sekadende, Tanzania Fisheries Research Institute- Dar es Salaam Centre, P.O. Box 78850, Dar es Salaam, Tanzania

Fisheries research Institute, Research officer

Shigalla B. Mahongo, Tanzania Fisheries Research Institute, Institute Headquarters, P.O. Box 9750 Dar es Salaam, Tanzania.

Fisheries research Institute, Research officer

Mathias M. Igulu, WIOMSA Mizingani Street, P.O. Box 3298, Zanzibar, Tanzania

WIOMSA, MASMA Program manager

Published
2021-02-11

Journal Identifiers


eISSN: 0856-860X
print ISSN: 0856-860X