GROWTH AND REPRODUCTION OF THE ROBALO Centropomus nigrescens (TELEOSTEI: CENTROPOMIDAE) IN MANZANILLO BAY, MEXICAN CENTRAL PACIFIC

Espino–Barr E; Gallardo–Cabello M; Puente–Gomez M; Garcia–Boa A

Volume : VI, Issue : XII, December - 2017

GROWTH AND REPRODUCTION OF THE ROBALO Centropomus nigrescens (TELEOSTEI: CENTROPOMIDAE) IN MANZANILLO BAY, MEXICAN CENTRAL PACIFIC

Espino Barr E, Gallardo Cabello M, Puente Gomez M, Garcia Boa A

Abstract :

Specimens of black snook Centropomus nigrescens were collected from October 2013 to December 2015. The maximum value of TL was 101.0 cm and the minimum was 11.1 cm, Total weight varied from 5.26 g to 9 810.00 g. Each year a fast growth band and a slow growth band are deposited on the sagittae and asterisci, equivalent to one year of age. The growth index value of the weight–length equation was positive allometric: b = 3.161 with total weight data and b = 3.15 with eviscerated specimens. Growth parameters obtained by Ford–Walford–Gulland method for total length were: L_�= 103.55 cm, k = 0.14 years^–1, and t_o= 0.00. Growth parameters obtained by convergent iteration process were L_� = 103.53 cm, k= 0.14 years^–1, t_o= 0.00. The calculated asymptotic total weight was Wt_�= 9 749 g and the eviscerated asymptotic weight We_�= 8 863 g. Longevity was of 21.4 years. The proportion of male: female was 1: 1.65. Length of first maturity was L₂₅ = 59.00 cm in females and males, and first reproduction length was L₅₀ = 76.4 cm in females and L₅₀ = 59.0 cm in males. The allometric value of the hepatosomatic index (HSI) relationship was b = 2.95 Maximum values were observed in June, July, November, Feuary, and April. Spawning stage in females and males at 100 % in June and July.The gonadosomatic index (GSI) reached its highest value during June. The gastric repletion index showed higher values during June, July, November, Feuary and April. The higher values of the condition factor are obtained in the months of June, July, October and November. Oocyte diameter were 0.34 mm average, minimum 0.33 mm and maximum 0.39 mm. Fecundity values ranged from 21.7 million to 40.1 million with a mean of 29.1 million oocytes in females of 89 cm to 101 cm. Relative fecundity was of minimum 2 273, maximum of 4 023.6, and average 3 081.7 oocytes per gram of gonad, and per gram of the organism 54 231.9 average (30 237.9 to 90 713.7 oocytes per organism gram).