ANALYSIS OF THE GONADAL DEVELOPMENT OF PARGO Lutjanus colorado BY MEANS OF BLOOD TESTING IN WILD ORGANISMS FOR ITS REPRODUCION IN CAPTIVITY IN SINALOA MEXICO

In the north of the Sinaloa coast, the red snapper, Lutjanus colorado, is considered one of the most important fish species because of its commercial and nutritional value. 206 organisms were stacked during the four seasons (winter, spring, summer and autumn) of 2016, from the San Ignacio-Navachiste-Macapule. The blood samples of 1.5 ml were extracted from each fish. The following biochemical parameters in blood were analyzed: protein (PT), cholesterol (COL), triglycerides (TRG), glucose (GLU), vitellogenins, and hematocrit. Red cell (RBC), white cell (WBC) and thrombocyte (TBC) were estimated. Also, the gastric repletion index (GI), gonadosomatic index (GI), hepatic index (HI), and condition factor (K) were obtained. Water physicochemical parameters such as temperature (°C), salinity (ppm), dissolved oxygen (OD), hydrogen potential (pH), nitrites (NO₂), nitrates (NO₃), ammonium (NH₄) and phosphates (PO₄) were also determined. Fish body weight and total length (LT) ranged from 81.3 to 2,040 g, and from 17.5to52.7 cm, respectively. The IRG (3.16±0.25) and K (1.27±0.01%) indexes were higher in summer, whereas the higher GI and HI values were obtained in autumn, with averages of 0.11±0.01 and 1.8 ± 0.12%, respectively. For PT and COL, the higher concentrations were observed in autumn, with averages of 7.54±0.44 g/dL and 166.60±7.8 mg/dL, respectively, whereas the higher values of TRIG and GLU were obtained in summer and spring, with averages of 185.23 ± 10.8 and 46.56±2.23 mg/dL, resp. For HTO and RBC the higher values were observed in summer, with averages of 43.10 ± 0.98 % and 2.68±0.04 x10⁶ células μl^⁻1, while WBC and TBC in winter and summer were higher, with averages of 8.08 ± 0.69 x10³ and 32.17 ± 1.08 x10³ células μl^⁻1. The highest value of vitellogenin per season was obtained in spring (121.22±16.95 μg/ml). In relation to the determination found in organisms of 25 cm (116.72±29.37 μg/ml) and with respect to the weight found in organisms of 587 g (101.40±16.30 μg/ml). The obtained results contribute to better understand on the reproductive physiology of the red snapper from the wild, and the development of its culture in captivity.