Spawning season of Indian mackerel (Rastreliger kanagurta) in Massawa coastal waters, Southern Red Sea, Eritrea

Abstract

Indian mackerel, Rastrelliger kanagurta (Cuvier, 1817) is a group of small pelagic schooling fish that belongs to Scombridae family and that has high economic value and ecological importance. Spawning season and sexual maturity of Rastreliger kanagurta was studied in Eritrean Red Sea around Massawa coast studied from June 2022 to May 2023. Monthly data were collected from artisanal (footfishermen) who caught the fish using hook and line. A total of 638 individuals comprising 64.6% females, 33.5% males and 1.9% unsexed were sampled and analyzed. The morphometric measurements including total length, fork length and standard length of fish in each sample were measured using a ruler to the nearest centimeter, and the total body weight and gonad were also measured using digital balance to the nearest gram. The length weight relationship for female was analyzed and expressed as: TW = 0.0566TL2.4538 (r² = 0.72, n = 412) and for male as: TW = 0.0225TL2.7656 (r² = 0.684, n = 214). . The spawning season was prolonged period extending from July to November with a peak during September for female and October for male. The first sexual maturity size (L50) of female was 19.56 cm TL and 19.29 cm TL for male Rastreliger kanagurta.