Age, Growth and Ovarian Histology of Sardinella aurita (Valenciennes, 1847) in the South of Atlantic Moroccan Coast

Abstract

Otoliths reading and length frequency distribution were used for age determination and growth estimation of Sardinella aurita (round sardinella) stock of Southern Atlantic coast of Morocco. Both otoliths' method for age determination and Bhattacharya’s method for length frequency analysis showed five age groups. The growth performance index revealed that there is significant accordance among method of length frequency distribution and otoliths reading for stock assessment studies of Sardinella aurita stock in the south of Morocco. The microscopic observation of female gonads using histology method was investigated for the first time in our study area and confirms the presence of five principal stages of ovary of sardinella aurita: immature, maturing virgin and recovering spent, mature (or pre-spawning phase), spawning, post-spawning or spent. In addition, our results of the fecundity showed that the mean relative fecundity obtained is estimated at 193 ± 98 oocytes/g which is lower compared to those obtained in other areas in the Atlantic coast.

Yeni Calabar Nehri’nde (Nijer Deltası, Nijerya) Yuvarlak Sardalyanın (Sardinella aurita, Valenciennes, 1847) Büyüme, Ölüm Oranı ve Sömürülme Oranı

“…The ratio of sex changed significantly when the fish attained maturity, and there were variations in the sex-ratio dependent on the size of the reproductive unit. The sex-ratio favored males (51%) to females (49%), which is in line with the findings of Bensahla-Talet et al (1988) and Lawson and Doseku (2013) in Majidun Creek, Lagos, Nigeria, but contradicts the findings of Baali et al (2015), who recorded a higher percentage value for females (63.98%). Sex-ratio varies with respect to size ranges.…”

Reproductive traits of the round sardinella in the Canary Islands (Spain, NW Africa)

“…In fact, expansion of species leads to transboundary geographic distributions, which in the case of S. aurita is promoting several projects whose aim is to facilitate collaboration between countries involved to share stocks to achieve the coordinated management programmes in NW Africa, such as the 'Shared sardinella' project (FAO, 2022). The length at first maturity estimated for S. aurita inhabiting the Canary Islands waters (18 cm) is notably smaller than the LFMs estimated in NW African waters (ter Hofstede et al, 2007;Baali et al, 2015Baali et al, , 2017Amenzoui & Baali, 2018;Ndiaye et al, 2018;Jurado-Ruzafa et al, 2020, among others). This is a common result in other small pelagic species, probably due to the more favourable oceanographic conditions in the continental NW African coasts, characterized by the influence of one of the four major upwelling systems of the world (Barton et al, 1998;Cury et al, 2020).…”

“…The length at first maturity estimated for S. aurita inhabiting the Canary Islands waters (18 cm) is notably smaller than the LFMs estimated in NW African waters (ter Hofstede et al ., 2007; Baali et al ., 2015, 2017; Amenzoui & Baali, 2018; Ndiaye et al ., 2018; Jurado-Ruzafa et al ., 2020, among others). This is a common result in other small pelagic species, probably due to the more favourable oceanographic conditions in the continental NW African coasts, characterized by the influence of one of the four major upwelling systems of the world (Barton et al ., 1998; Cury et al ., 2020).…”

Prenatal kisspeptin antagonist exposure prevents polycystic ovary syndrome development in prenatally-androgenized rats in adulthood: An experimental study

“…After the blood collection, rats were killed by heart incision, and the ovaries were immediately removed from the body cavity and prepared for histological studies using the method described by Baali et al (24), with some modifications.…”