Wenceslao Valenzuela-Quiñónez

Artisanal fisheries in the conservation zones of the Upper Gulf of California

Marine protected areas (MPAs) are increasingly being used as management tools to protect ecosystems around the world, but there is some debate as to whether ...

Interannual variation of growth of the brown shrimp Farfantepenaeus californiensis and its relation to temperature

Abstract We evaluated the interannual variation in the growth of brown shrimp Farfantepenaeus californiensis and the relation of this variation with sea surface temperature in the Gulf of California, Mexico. We used daily samplings of commercial captures at the packing plant at Guaymas, Sonora, Mexico from 1978 to 1994, samplings of commercial captures on board trawlers of the commercial fleet that operated along the coast of Sonora during the fishing seasons 1989–1995, and the monthly average of the sea surface temperature recorded by the oceanographic station of the Institute of Geophysics of the National University of Mexico, in Guaymas, Sonora from 1978 to 1995. The growth in the brown shrimp showed clear interannual variations. The relation between the temperature and the φ′and temperature and the growth coefficient K could be represented by a gaussian function that was significant (P

The Effect of Low Salinity Water with Different Ionic Composition on the Growth and Survival of Litopenaeus vannamei (Boone, 1931) in Intensive Culture

The effects of four different ionic composition low salinity water (T1, T2, T3, and T4), on growth and survival of Litopenaeus vannamei marine shrimp juveniles were investigated. Shrimp culture in seawater (Tm) was used as control treatment. The results indicated that there were no significant difference (P < 0.05) in growth, survival, production, and feed conversion ratio (FCR) of L. vannamei juveniles reared in the different treatments, but significant differences (P < 0.05) were observed between each of them when compared with seawater (Tm). After 84 days, culture shrimp grew from 0.02 to 7.58 g in T1. The lowest growth rate was attained in T3 (0.57 g/week), in which potassium and calcium ions concentrations were the lowest (0.58 and 28.00 mg/L, respectively). The recorded survival rate (76.35% to 79.55%) is considered well for the 84 days growout period, although it was 7.6% lower than that recorded in the control treatment. Although there were no significant differences (P < 0.05) in growth with respect to the ionic composition of the four treatments, there was a trend of increasing growth in relation with the ionic ratio found in the seawater (Tm). This aspect should be evaluated more closely in future research.

Efecto de diferentes combinaciones de temperatura y salinidad sobre el consumo específico de oxígeno en el camarón blanco Litopenaeus vannamei

The combined effect of different temperatures (20, 25 and 30°C) and salinities (15, 25, 35 and 45 psu) on the specific oxygen consumption (CEO) in Litopenaeus vannamei was determined. For this, CEO of 248 organisms of different body sizes (0.31 to 15.85 g) was measured. The CEO decreased when shrimp weight increased in all treatments without presenting a definite pattern when the salinity increased; even though all the combinations of temperature and salinity did not statistically show slopes significantly different in the regression models for CEO and organism weight relationships. The slope values suggest that at 20°C there is high energy expenditure at 15 psu, and at 25°C the highest energy consumption occurs at 45 psu. Whereas at 30°C, the lowest energy consumption occurred combined with the lowest salinity (15 psu). This may indicate that the isosmotic condition (point of lowest energy expenditure) tends to change with temperature, which may imply that the shrimp can be cultivated at high temperature (30°C) and at low salinities (15 psu) without increasing energy expenditure.

HABITAT USE FOR GROWTH AND RECRUITMENT OF THE PACIFIC YELLOWLEG SHRIMP, FARFANTEPENAEUS CALIFORNIENSIS (DECAPODA, PENAEIDAE) ON THE CONTINENTAL SHELF AND ADJACENT LAGUNA AGIABAMPO, MEXICO

[This study analysed growth and recruitment of Pacific yellowleg shrimp, Farfantepenaeus californiensis (Holmes, 1900) populations inhabiting semi-arid coastal lagoons and the continental shelf in a semi-arid, subtropical region in the Gulf of California, Mexico. Sampling of the yellowleg shrimp population was conducted in the coastal lagoon and offshore on a monthly basis from December 2001 to November 2003. The length of females ranged from 90 to 150 mm, greater lengths were more common offshore during April and July. In the lagoon, smaller specimens prevailed all year. There were no significant differences between lagoon and offshore in mean length to within 1% of probability. The dynamics of penaeid shrimp in semi-arid climate lagoons differ from the pattern found in more semi-tropical parts of the Mexican Pacific, where lagoons do not have permanent communication with the Gulf of California. Evidence suggests that this species can complete its life cycle in the lagoon system or on the continental shelf. Este estudio analizo el crecimiento y reclutamiento de la poblacion de camaron cafe del Pacifico Farfantepenaeus californiensis (Holmes, 1900) en lagunas costeras y en la plataforma continental de una region subtropical semiarida en el Golfo de California, Mexico. Se realizaron muestreos biologicos mensuales de las poblaciones de camarones en laguna y plataforma, de diciembre del 2001 a noviembre del 2003. La longitud total de las hembras se encontro en el intervalo de 90 a 150 mm, las tallas mas grandes se capturaron en la plataforma en los meses de abril y julio. En la laguna, camarones mas pequenos prevalecieron a lo largo del ano. La comparacion estadistica de la longitud media entre laguna y plataforma mostro que no existen diferencias significativas al 1% de probabilidad. La dinamica de las poblaciones de camarones Peneidos en lagunas de clima semiarido difiere del patron encontrado en zonas con clima mas semitropical del Pacifico mexicano, donde las lagunas no tienen comunicacion permanente con el Golfo de California. La evidencia sugiere que esta especie puede realizar el ciclo de vida en lagunas o en la plataforma costera., This study analysed growth and recruitment of Pacific yellowleg shrimp, Farfantepenaeus californiensis (Holmes, 1900) populations inhabiting semi-arid coastal lagoons and the continental shelf in a semi-arid, subtropical region in the Gulf of California, Mexico. Sampling of the yellowleg shrimp population was conducted in the coastal lagoon and offshore on a monthly basis from December 2001 to November 2003. The length of females ranged from 90 to 150 mm, greater lengths were more common offshore during April and July. In the lagoon, smaller specimens prevailed all year. There were no significant differences between lagoon and offshore in mean length to within 1% of probability. The dynamics of penaeid shrimp in semi-arid climate lagoons differ from the pattern found in more semi-tropical parts of the Mexican Pacific, where lagoons do not have permanent communication with the Gulf of California. Evidence suggests that this species can complete its life cycle in the lagoon system or on the continental shelf. Este estudio analizo el crecimiento y reclutamiento de la poblacion de camaron cafe del Pacifico Farfantepenaeus californiensis (Holmes, 1900) en lagunas costeras y en la plataforma continental de una region subtropical semiarida en el Golfo de California, Mexico. Se realizaron muestreos biologicos mensuales de las poblaciones de camarones en laguna y plataforma, de diciembre del 2001 a noviembre del 2003. La longitud total de las hembras se encontro en el intervalo de 90 a 150 mm, las tallas mas grandes se capturaron en la plataforma en los meses de abril y julio. En la laguna, camarones mas pequenos prevalecieron a lo largo del ano. La comparacion estadistica de la longitud media entre laguna y plataforma mostro que no existen diferencias significativas al 1% de probabilidad. La dinamica de las poblaciones de camarones Peneidos en lagunas de clima semiarido difiere del patron encontrado en zonas con clima mas semitropical del Pacifico mexicano, donde las lagunas no tienen comunicacion permanente con el Golfo de California. La evidencia sugiere que esta especie puede realizar el ciclo de vida en lagunas o en la plataforma costera.]

Multi-model inference for growth parameter estimation of the Bigeye Croaker Micropogonias megalops in the Upper Gulf of California

El chano norteno Micropogonias megalops es capturado en el Alto Golfo de California (AGC) por comunidades de pescadores locales de San Felipe en Baja California, El Golfo de Santa Clara y Puerto Penasco en Sonora, Mexico. Para la administracion sustentable de la pesqueria, es necesario conocer el crecimiento de la especie. Se calculo el crecimiento individual de M. megalops del AGC usando 4 ecuaciones: la ecuacion de crecimiento de von Bertalanffy (ECVB), Logistico, Gompertz y Schnute. Los parametros de cada modelo y los intervalos de confianza (IC) fueron calculados usando el metodo de maxima verosimilitud. El mejor modelo se selecciono con el criterio de informacion de Akaike (CIA). Segun el CIA, la ECVB es la que mejor describe los datos. Los parametros y sus IC fueron: 1) Longitud asintotica promedio (L∞) en machos 429 mm de longitud total LT (IC 426-432 mm LT) y en hembras 461 mm LT (IC 457-464 mm LT); 2) el coeficiente de crecimiento (k) en machos 0,419 (IC 0,412-0,426) y en hembras 0,377 (IC 0,370-0,384). En conclusion, la ECVB describe adecuadamente el crecimiento individual de M. megalops en el AGC.

APPLICATION OF AN EGG PRODUCTION INDEX TO DETERMINE REPRODUCTIVE PERIOD OF THE BROWN SHRIMP FARFANTEPENAEUS CALIFORNIENSIS NEAR AGIABAMPO, SONORA-SINALOA, MEXICO

Abstract Using the percentage of mature females as an index, the reproductive period of the brown shrimp, Farfantepenaeus californiensis, off the coast of Sonora in Mexico, has been shown to occur throughout the year with two peaks of mass spawning. The objective of this study is to determine if a similar reproductive period occurred off Agiabampo, at the Sonora-Sinaloa border. By combining 3 indices of mature females: size structure, abundance and fecundity at size, a single egg production index (EPI) was calculated. Monthly samples from January through December 2002 were collected during 5 continuous days around the full moon (full moon ± 2 days). Trawl net tows were used at depths from 1–9 m, 2 km north and south of the mouth of a coastal lagoon. Using the EPI, a single reproductive peak, May to August, was found, with May as the most important egg production month. On the other hand, the percentage of mature females showed a two peak reproductive period, one more intensive from May to August and the second one less intensive in November. We concluded that the best determination of the reproductive period of the brown shrimp required the use of three indices. Particularly off Agiabampo, this species has a well-defined reproductive period with just one massive spawning peak.

Effect of tidal hour on the abundance of penaeid shrimp postlarvae (Decapoda, Penaeidae) along the Mexican Pacific coast

In the present study we explored the effect of the tidal hour on the postlarvae abundance of the penaeid white-leg shrimp ( Litopenaeus vannamei (Boone, 1931)) in three Mexican Pacific coastal lagoons. Correlation analysis of tidal hour against the hourly variation of the abundance of postlarvae was conducted in three regions of the Mexican Pacific; the system lagoon Huizache-Caimanero LHC, the region of the “Grandes Lagunas” SGL and the “Mar Muerto” Lagoon LMM. Two peaks were found in L. vannamei abundance in the three locations, at 04:00 and 16:00 of tidal hour in LHC and SGL, and 06:00 and 12:00 of tidal hour in LMM. Significant correlations between postlarvae and the tidal hour for the three regions were found. The tidal hour standardizes the time of ebb and flow. It is concluded that tidal hour can be used as cue for shrimp postlarvae immigration to nurseries.

Use of organic and inorganic fertilization in zero-discharge tanks and ponds and its effects on plankton and shrimp Litopenaeus vannamei performance

The aim of this study was to investigate the effects of organic (molasses) and inorganic (Nutrilake®) fertilization on plankton, water quality, and shrimp Litopenaeus vannamei performance reared in zero-discharge tanks and ponds. The findings showed that in tanks, the organic fertilization induced highest survival and production, and low total ammonia-N concentration; however, this effect was not observed in the ponds. In both tanks and ponds, the inorganic fertilization increased nitrogen levels. The phytoplankton abundance increased in both tanks/ponds with the fertilization treatments. Shrimp production in the tanks and ponds fertilized almost doubled compared with unfertilized treatments.

Respuesta de metabolitos en hemolinfa y desempeño productivo del camarón blanco del Pacífico Litopenaeus vannamei cultivado a altas densidades en laboratorio

In shrimp farming, one of the most important challenges is to increase shrimp production, which has encouraged increased seeding rates. In this study, the response of metabolites in hemolymph and performance of white shrimp (Litopenaeus vannamei) grown at high densities was evaluated, using total protein, lactate and glucose concentrations as stress indicators. At the beginning of the bioassay, lactate was high, while growth and specific survival were poorer, which is inferred as a response to seeding- time stress. At the end of the bioassay was obtained statistical difference in total protein levels, with an increase of final weight and survival.