Seasonal changes in maturational status, body condition, and population structure in the Moroccan Atlantic Sardine Sardina pilchardus (Teleostei: Clupeidae) from Safi fishing

Aspects of reproduction and population structure were investigated between June 2017 to May 2018 in sardines, Sardina pilchardus (Walbaum, 1792) from the Safi fishing area. The sex ratio was generally in favor of males (chi(2) = 19.50). Out of 3252 total specimens sampled, 1404 were females (46.00%), 1648 males 50.68%) and 200 immatures (6.15%). The immatures were best represented in the small size classes, between 8 and 12 cm. This study showed that sardines can breed throughout the year with a peak breeding season between November and February. The gonado-somatic index (GSI) and the condition coefficient (CC) evolved almost invariably. The volumetric absolute body condition index [kv= Fresh total body mass (g)/total body volume (cm3)] showed two peaks, which are discriminately sex dependent. For females, the peaks are concomitantly observed in September and April while for males, these are shown in June and February. Moreover, the morphometric index (k(n)) showed a single peak in January and September for reproductive males and females, respectively. As regards the nonreproductive individuals the males have two peaks in June and December or females, they have one peak in November. Additionally, the GSI showed a single peak in February. The size at first sexual maturity in males and females was 16.1 cm and 16.5 cm, respectively. (C) 2020 Elsevier B.V. All rights reserved.