Search

The aim of this study was to determine the prevalence and severity of the diseases: acute hepatopancreatic necrosis disease (AHPND), necrotizing hepatopancreatitis (NHPB) caused by intracellular bacterium (Hepatobacter penaei), septic hepatopancreatic necrosis (NHPS), and the white spot syndrome virus (WSSV) in farmed shrimp during two productive cycles (spring and summer) in the years (yrs) 2016 and 2017. From 360 studied shrimps, 90% showed external characteristics of apparently healthy animals, while only 10% of the specimens presented red coloration, soft cuticle, and muscular opacity. AHPND was the disease with the higher average prevalence for all the studied zones and seasons, with a prevalence of 53.33% in 2016 and 60.16% in 2017, followed by NHPS with 36.66% in 2016 and 42.83% in 2017. The incidence of WSSV was the lowest compared to the other diseases studied in this work, with 16.16% in 2016 and 20% in 2017; NHPB was only observed in summer with an average prevalence of 16.16% for both yrs. The northern area of Mexico registered the highest rates of mortality associated to these diseases, excluding WSSV, which resulted in being the most prevalent disease in the southern area (although such difference it is not statistically significant). The specimens diagnosed with AHPND exhibit severe damage in hepatopancreas as well as cellular detachment in the intestinal proximity. The organisms with NHPS showed multifocal cellular detachment in hepatopancreas and bacteria growth in heart, gills, lymphoid organ, connective tissue and muscles. The physicochemical variables considered for this study did not show significant variability among the zones and seasons analyzed, however, any alteration on these parameters might cause stress in the shrimps impairing the immune response against opportunistic pathogens. The presence of bacterial and viral diseases identified in this work is likely related to a low quality of the post-larvae, or an inadequate farming environment. El objetivo del presente estudio fue determinar la prevalencia y severidad de las enfermedades Necrosis Aguda del Hepatopáncreas (AHPND), Necrosis del Hepatopáncreas (NHPB) causado por bacterias intracelulares (Hepatobacter penaei) , bacteriosis (NHPS) y el virus de la mancha blanca (WSSV), en camarones de cultivo durante dos ciclos (primavera y verano) en los años 2016 y 2017. Los resultados de los 360 camarones colectados mostraron características externas de animales aparentemente sanos (90%) y 10% con coloración rojiza, cutícula suave y opacidad muscular. AHPND fue la enfermedad con mayor prevalencia promedio para todas las zonas y temporadas con 53,3% en 2016 y 60,6% en 2017, seguida de NHPS con 36,66% en 2016 y 42,3% en 2017. La prevalencia de WSSV fue baja respecto a las demás con 16,16% en 2016 y 20% en 2017. NHPB se presentó en verano con prevalencias de 16,6 para 2016 y 2017. La zona norte presentó la mayor prevalencia de las enfermedades excluyendo a WSSV, misma que obtuvo una prevalencia mayor en la zona sur que en las demás zonas (sin embargo, dicha diferencia no es estadísticamente significativa). Los organismos con AHPND presentaron daños severos en hepatopáncreas con desprendimiento celular de la región proximal al intestino y NHPS con desprendimiento celular multifocal en hepatopáncreas y presencia de colonias de bacterias en corazón, branquias, órgano linfoide, tejido conectivo, musculo y ciegos hepáticos. Los parámetros fisicoquímicos en este trabajo no tuvieron diferencias significativas entre zonas en cada temporada, sin embargo, la alteración de alguno de ellos ocasiona estrés en los camarones, reduciendo la actividad anti-patógenos oportunistas. La presencia de las enfermedades bacterianas y virales identificadas en este trabajo probablemente estuvieron relacionadas con la calidad de la postlarva, o por un inadecuado ambiente de cultivo, propiciado por acumulación de materia orgánica 198-206 marisol@ciad.mx

El pargo colorado (Lutjanus colorado) es una especie con un alto valor comercial en el mercado mexicano, con potencial para su cultivo. Hasta la fecha no existen estudios sobre su reproducción, cultivo larvario y engorda en cautiverio. El presente trabajo es el primer reporte sobre la descripción a detalle del desarrollo embrionario de la especie bajo condiciones de cultivo. Los huevos fertilizados viables del pargo colorado son pelágicos, esféricos, transparentes y con una sola gota de aceite. Midieron 0,77±0,09 mm de diámetro y la gota de aceite 0,14±0,01 mm. La primera división ocurrió a las 0,05 horas post fertilización (HPF). La eclosión se llevó a cabo a las 17,22 HPF bajo las condiciones del presente estudio. Las larvas recién eclosionadas midieron 1,8±0,1 mm de longitud total (LT). El desarrollo embrionario de esta especie fue similar a la descrita para especies de la misma familia. Los resultados del presente estudio aportan información básica para iniciar el desarrollo de la biotecnología para la producción de semilla de esta especie a escala comercial. The Colorado snapper (Lutjanus colorado) is one of the most commercially important fish species in México and it is considered a suitable candidate for culture. Until now, no research has been carried out on its reproduction, larviculture and fattening in captivity. This study is the first description of embryonic development of this species under controlled conditions. Fertilized eggs of Colorado snapper are pelagic, spherical and transparent and contain one drop of oil. Eggs measured 0.77±0.09 mm and the drop of oil 0.14±0.01 mm. First cell division occurred at 0.05 h post-fertilization (HPF), hatching at 17.22 HPF under the above described conditions. Larvae total length (LT) was 1.8±0.1 mm. Embryonic development of this species was similar to other lutjanidae species. These results provide basic information for developing the necessary biotechnology for commercial seed production of the Colorado snapper.

El botete diana Sphoeroides annulatus es un pez marino con alto valor en el mercado mexicano con potencial para su cultivo. Las investigaciones sobre los aspectos reproductivos y cultivo de larvas de esta especie, iniciaron en México a partir de 1997 en el Centro de Investigación y Alimentación (CIAD), Unidad Mazatlán. El presente trabajo describe el desarrollo de la biotecnología para la producción masiva de juveniles; la cual incluye los protocolos para la inducción hormonal, desove, fertilización e incubación de huevos, cultivo de alimento vivo y cultivo de larvas. The bullseye puffer fish Sphoeroides annulatus is an important marine species due to its culture potential and high market value in Mexico. Research on aspects of reproduction and larvae culture of this puffer fish commenced in México in 1997 at Centro de Investigación en Alimentación y Desarrollo (CIAD-Mazatlan Unit), Mazatlán, Sinaloa. This work describes the following biotechnological developments for obtaining mass production of the bullseye puffer fish juveniles: hormonal induction methods, spawning, egg fertilization and incubation, culture of live feed and larviculture.

Recent findings show that eliminating the gelatinous egg capsule surrounding the fertilized eggs of the puffer fish Sphoeroides annulatus improves embryonic development and hatching rate. In this work, the following 3 different desticking procedures were used to evaluate larval growth and survival: 5 ml L-1 proteolytic protease enzyme (EPP), 1% of pineapple juice (JP) and eggs with no sticky coating on the surface as a control (C). All treatments were carried out in triplicate and the experiment lasted for 33 days. The fertilization percentage obtained was 98.6 ± 1.8% in all treatments. The highest hatching percentage was achieved with EPP (93.03 ± 3.01%) and the lowest with JP (80.97 ± 3.97%). Both total length (LT) (14.4 ± 0.40 mm) and weight (P) (0.118 ± 0.004 g) were significantly higher in the JP treatment. The highest survival rate was obtained with EPP (19.34 ± 1.98%) and differences were found to be statistically significant. The desticking of eggs treated with JP gave a low hatching percentage due to the fruits pH reading of 4 and since fewer organisms were produced, higher growth rate was obtained. Thus, we conclude that removing the adhesive layer of the egg does not affect larval growth and survival.

Se evaluaron tres tratamientos profilácticos, a tres dosis diferentes cada uno, para desinfectar huevos de botete diana Sphoeroides annulatus y determinar su efecto en la reducción de la carga bacteriana y el porcentaje de eclosión. Los huevos fueron tratados con enzima proteolítica para desgomarlos. Los tratamientos se realizaron por triplicado: acriflavina (A) a concentraciones de 2,5, 5, y 10 ppm por 1 min, formalina (F) a 10, 50 y 100 ppm por 30 min y glutaraldehído (G) a 50, 100 y 200 ppm por 5 min y un grupo control sin tratamiento (C). Se inoculó por duplicado una muestra de huevos de cada réplica en agar TCBS y marino para evaluar el crecimiento bacteriano (UFC mL-1); los huevos se incubaron y se determinó el porcentaje de eclosión. Los resultados del recuento en todos los tratamientos fueron negativos para Vibrio spp.; sin embargo, las bacterias heterótrofas se presentaron en todos los tratamientos; en G-100 ppm se observó la menor cantidad de UFC (4,00 ± 2,8 x 10² mL-1) y las más altas se obtuvieron en A-2,5 y F-50 (3,45 ± 0,4 x 10(4) y 5,73 ± 0,3 x 10(4) UFC mL-1, respectivamente). El porcentaje de eclosión más alto se obtuvo en los huevos sin desinfectar (96,1 ± 6,2%), a pesar de la cantidad de bacterias presentes (1,22 ± 0,1 x 10(4) UFC mL-1) y el porcentaje de eclosión más bajo se presentó en los huevos desinfectados con A-5 (12,3 ± 6,3%). Por lo tanto, se recomienda solo eliminar la capa adherente de los huevos antes de la incubación. Three prophylactic treatments using three dosages each were used as surface disinfectants in bullseye puffer Sphoeroides annulatus eggs to study their effect on bacterial load reduction and hatching rate. Eggs were treated with proteolytic enzyme to remove stickiness. Tested treatments were: acriflavine (A) at a concentration of 2.5, 5 and 10 ppm for 1 min; formalin (F) at 10, 50 and 100 ppm for 30 min and glutaraldehyde (G) at 50, 100 and 200 ppm for 5 min, as well as a control group with no treatment (C), using three replicates per treatment. After disinfection, an egg sample from each replicate was inoculated in duplicate on TCBS and marine agar culture media to assess bacterial growth (CFU mL-1). The eggs were incubated and their hatching rate determined. Culture media tested negative for Vibrio spp. in all treatments. However, the growth of heterotrophic bacteria was present in all experimental groups; G-100 showed a significant reduction in CFU (4.00 ± 2.8 x 10² mL-1), whereas A-2.5 and F-50 had significantly higher CFU values (3.45 ± 0.4 x 10(4) and 5.73 ± 0.3 x 10(4) mL-1 respectively). By not disinfecting the eggs, a higher hatching rate was obtained (96.1 ± 6.2%), however relatively high CFU counts (1.22 ± 0.1 x 10(4) mL-1) were observed in this treatment, while the lowest hatching rate was found in eggs disinfected with A-5 (12.3 ± 6.3%). Thus, the use of stickiness removal procedures prior to incubation of bullseye puffer eggs seems to be enough to produce good hatching rates.

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.