Age and Growth of the Areolate Grouper <i>Epinephelus areolatus</i> from the Gulf of Suez

Abstract

Age and growth of the associated coral reef grouper, Epinephelus areolatus, were estimated for samples collected from the artisanal fishery in the Gulf of Suez during November 2013 and October 2014. Otoliths of 597 specimens ranged in length from 11.2 to 50.5 cm were used in age determination. The otoliths showed alternating opaque (light) and translucent zones when seen by reflected light against a dark background, a translucent zone plus the opaque zone immediately around it formed an annulus. According to the otolith examination, the maximum life span of E areolatus was eight years with mean lengths of 16.9, 24, 29.9, 35.7, 39.7, 43.4, 46.6 and 49.7 cm for the age groups from one to eight respectively. Individuals belong to age group two constituted the bulk of the catch with more than 60% of the population. The results showed that the E. areolatus is a relatively slow growing species and the values of the von Bertalanffy growth function was estimated as K = 0.154, L ∞ = 66.55 cm (LT) and t 0 = −0.91 years. The estimated growth performance index is 2.83. The length weight relationship was estimated as a = 0.0135 and b = 2.9947, r 2 =0.981 indicating an isometric growth of the weight relative to the length.

Age and Growth of Epinephelus fasciatus from northern Red Sea

“…The annual increments were found to be 6.6, 4.6, 3.3, 2.2, 1.6, 1.2 and 0.8 cm during second, third , fourth, fifth, sixth, seventh and eighth years of life respectively. These observations are in close agreement with those recorded by Rajaguru (1992) who studied Cynoglossus arel, and C. lida from Indian water, Laban (2008) who studied Solea aegyptiaca in the Mediterranean Sea, Abd-Allah et al (2015) who studied Epinephelus areolatus in Gulf of Suez, and Osman (2016) and ElGanainy et al (2017) who studied Sphyraenia chrysotaenia in the Gulf of Suez. All of them described the increment in growth as very rapid growth rate during the first year of life…”

“…However the growth coefficient (K) in the present study is higher than that was recorded by Wahbeh (2005) in Aqaba, Jordon, with age ranging between 1 and 7 years. Furthermore, the growth coefficient (K) in the present study is higher than that of Epinephelus areolatus that studied in the Gulf of Suez by Abd-Allah et al, (2015) were calculated as 0.154 yr -1 . Kasim & Balasubraman (1990) and Pajuelo & Lorenzo (1998) referred to the effect of the sample size on estimates of L ∞ , K and t 0.…”

“…And Kandula et al (2015) recorded the lengthweight relationship as isometric off eastern Indian coasts for E. chlorostigma as (b = 3.04), E. tauvina (b = 3.07), E. coioides (b = 3.00) and E. malabaricus (b = 3.06). Also for Epinephelus areolatus In Gulf of Suez, the b value for combined sexes was calculated at 2.9947 and 3.0171 using total weight and gutted weight, respectively (Abd-Allah et al, 2015). Moreover, the b value for Cephalopholis argus, Epinephelus coioides, Epinephelus fuscoguttatus and Epinephelus tauvina in Kenya were calculated as 3.081, 3.041, 3.091 and 3.051 respectively (Agembe et al, 2010).…”

The Fishing Ground of Bottom Longline Vessels and Exploitation Rate of Tiger Grouper (<i>Epinephelus aerolatus</i>) in Arafura Waters

“…The growth coefficient (K) indicates the level of time it takes an individual to reach its asymptotic length Sparre & Venema, 1999). The value of this growth coefficient is not much different from those which were found in Kuwait which is 0.288/ year, but the asymptotic length is 39.10 cm (Mathews & Samuel in Marzuki & Djamal, 1992), Suez Bay K = 0.154 and L∞ = 66.65 cm (Abd-Allah et al, 2015) and in the Red Sea K = 0.13 and L ∞ = 78.92 cm (Hasan in Abd-Allah et al, 2015). Different length infinity was found in the Red Sea compared to Arafura, Suez Bay and Kuwaiti.…”