Maturity and Gonadosomatic Index of European Hake Merluccius Merluccius (Linnaeus, 1758) From the Egyptian Mediterranean Water

Abstract

Looking at the Mediterranean in particular, we find that its production decreased during the ten years from 77,799 tonnes in 2011 to 49,896 tonnes in 2020, and the quantities produced by some common fish families of economic and nutritional importance also decreased. Especially benthic fish, which are of great importance, especially for residents of coastal cities in the Egyptian country, such as bourbon fish, whose production decreased from 4,124 tonnes in 2011 to only 549 tonnes in 2020, and shrimp production, whose production decreased from 10799 tonnes in 2011 to 5460 in 2020, which is equal to a decrease of 50 % roughly. A total of 572 European hake individuals were collected from commercial demersal trawl fisheries and analyzed to estimate the reproductive biology. The sex ratio M/F was 1:2.16, which means that females dominate the catch. European hake spawns all year round. However, the peak of the gonadosomatic index was in the winter season from November to March, which indicates the peak of the spawning season. Length at the first sexual maturity was estimated at 34.4 cm for females. All of the fish sampled were in the third and fourth stages of maturity. The total length ranged from 17 cm to 69 cm, with an average length of 32.7 cm for all samples.

Population biology of European hake (Merluccius merluccius, Linnaeus, 1758) in Greece

“…The highest reproductive intensity in this study was observed during spring followed by winter. A number of studies in the region have reported spawning between November and March, including the Mediterranean coastline in Egypt [23], Central, and Western Mediterranean [21], the Sea of Marmara Turkey [11], and the Atlantic Moroccan coast [52]. Spawning season can be affected by several factors including temperature, food availability, and the condition factor [55].…”

“…Hake landings in Hellenic waters between 1992 and 2022 exhibited a declining trend, with an annual mean of 4,107 ± 889 tons [14] with Aegean catches representing on average (2010-2020) 81% the of the total Hellenic catches [15]. A fact of concern is that numerous reports indicate that the length at first maturity (L50) is higher than 20 cm [10,[16][17][18][19][20][21][22][23] which is the minimum landing size (MLS) in the Mediterranean, whereas the MLS in effect for hake populations of the Atlantic and North Sea is between 27 and 30 cm [24].…”