Luis Alvarez-Lajonchère

Efecto de la densidad de siembra sobre el crecimiento y supervivencia larval del pargo lunarejo Lutjanus guttatus

The effect on growth and survival of the initial stocking density (30, 20 and 10 eggs L-1) in larval rearing of spotted rose snapper (Lutjanus guttatus) was evaluated. The eggs were incubated in nine black fibreglass tanks with three replicates for treatment. Larvae were cultured in the same tanks using the green water technique. Larvae were harvested at 45 days post-hatch (DDE). Total length (LT), weight (PH) and survival rate (S) were determined. Initial stocking density did not affect growth and survival rates. Therefore, it is advisable to carry out larval culture of the spotted rose snapper using 30 eggs L-1 to maintain good growth levels.

Validation of an ovarian biopsy method for monitoring oocyte development in the fat snook, Centropomus parallelus Poey, 1860 in captivity

The validation of an ovarian biopsy method for in vivo assessment of oocyte maturation in Centropomus parallelus was studied. Diameters of intra-ovarian oocytes siphoned with cannula were analyzed fresh and preserved with 1% formalin in 0.7% NaCl solution. Oocytes in different stages were present along the ovaries, up to the tertiary yolk globule stage, which had a unimodal diameter frequency distribution. The oocyte diameter means were not significantly different at four sites along the ovaries (P > 0.05). Samples obtained with cannula were representative of the ovary central portion, in vivo and in vitro samples of the seven females examined were not significantly different (P > 0.05). An estimate of the coefficient of variation corrected for bias (P < 0.05) for 8 repeated in vivo samples was 1.9 ± 0.6. The results demonstrated that for the species, the biopsy method was satisfactory, providing representative samples of the ovaries.

Tratamientos profilácticos para desinfectar la superficie de huevos del pargo flamenco Lutjanus guttatus

For incubation of eggs, prophylactic treatments are applied to minimize negative effects of microorganisms on eggs and larvae. The effects of treatments with formaldehyde, acriflavine and glutaraldehyde to spotted rose snapper Lutjanus guttatus eggs, were studied. Reduction of colony forming units (CFU), the percentages of hatching, live larvae, live normal larvae and larval size, were studied. Best treatment with significant reduction of CFU, but without observable effects on the eggs with controls was with acriflavine at 5 ppm.

Evaluación de métodos para la eliminación de la capa adherente de los huevos del botete diana Sphoeroides annulatus (Pisces: Tetraodontidae)

Six different hatching treatments and one control were used to eliminate egg stickiness of fertilized bullseye puffer fish Sphoeroides annulatus eggs in this experiment. Each treatment was carried out in triplicate and the eggs were incubated in fiberglass tanks. A fertilization rate of 96.2% ± 2.4% was obtained and significant differences were observed between treatments. The highest hatching rate occurred at 96.4 ± 2% with the protease enzyme solution whilst the lowest rate was observed in the control (18.8 ± 5.3%). The hatching success of the bullseye puffer fish is significantly improved by eliminating egg adhesion.

Generation cycle closure of the spotted rose snapper, Lutjanus guttatus, in captivity

The spotted rose snapper, Lutjanus guttatus, is culture in several Latin American countries. The present study reports the generation closure with juveniles obtained from wild adults which matured and spawned at a Mazatlan laboratory (Mexico). F1 fish were sexually matured at 2 years of age, and spawning was induced in 2 successive years. F2 juveniles were reared until their sexual maturity and spawned at the same laboratory. Result indicate that a reliable supply of laboratory reared spawners can be achieved, avoiding the wild spawners dependence and allow the development of selection and genetic improve programs.

The use of three anaesthetics for handling spotted rose snapper Lutjanus guttatus (Pisces, Lutjanidae) broodstock

Benzocaine, 2-phenoxyethanol and MS-222 were tested as anaesthetics for several handling procedures with spotted rose snapper Lutjanus guttatus broodstock. Significant differences in time for induction and recovery were found with specific doses, as well as a direct correlation between the dose and the induction time. Each procedure demanded specific anaesthesia levels where the stage of deep anaesthesia should not be surpassed. The most effective agent for inducing deep anaesthesia was MS-222, with the least amount of time required for induction and recovery when using 100 mg l-1. It was followed by 250 µl l-1 of 2-phenoxyethanol, which was less costly.

Positive results of induced spawning and larval rearing experiments with Mugil liza Val., a grey mullet from Cuban waters

Abstract Induced spawning and larval rearing experiments were carried out with Mugil liza at Tunas de Zaza, Cuba. Of the 39 females treated with hormones, viable eggs and larvae were obtained from 9 females with natural or artificial fertilization. The best results were obtained with mullet pituitary homogenate (15 mg/kg), HCG with mullet pituitary homogenate (27–54 I.U./g with 18–48 mg/kg), HCG alone (53.1–60 I.U./g) and HCG with carp pituitary homogenate (12–41 I.U./g with 29.2–48 mg/kg) in that order, administered in three injections at 24-h intervals.