Effect of white spot syndrome virus (WSSV) and water exchange on survival and production of Litopenaeus vannamei under semi-intensive culture conditions.

A study was performed in two commercial shrimp farms in the province of Guasave, north of Sinaloa, Mexico, to assess the effects of the presence of the white spot syndrome virus (WSSV) and of water exchange on the growth rate, production, and survival of the Pacific white shrimp, Litopenaeus vannamei, during the fall-winter season in semi-intensive culture ponds. The experiment consisted of four treatments; in the first (T1), three earthen ponds with water exchange, were stocked with PCR-positive for white-spot syndrome virus (WSSV) postlarvae. In the second (T2), three earthen ponds were stocked likewise (PCR-positive), but without water exchange. In the third (T3), three earthen ponds, with water exchange were stocked with PCR-negative for white-spot syndrome virus (WSSV) postlarvae. In the fourth (T4), three earthen ponds were stocked likewise (PCR-negative), but without water exchange. The average growth rates were 0.56, 0.56, 0.80, and 0.75 g/week for T1, T2, T3, and T4, respectively. Survival was 23.2% (T1), 26.1% (T2), 64.3% (T3), and 66.1% (T4). Production ranged between 252.60 and 847.00 kg/ha, with the lowest production in T2 and the highest in T3. Feed conversion ratio ranged from 1.00 for T3 to 1.70 for T2. The final average weight ranged between 10.6 g (T2) to 12.5 g (T3). The WSSV can affect negatively the growth rate (30%), the survival (64%), and the production (69%) in comparison with PCR-negative organisms.No differences in weight were found between WSSV-infected and non-infected individual shrimps, as well as in nested-PCR positive against single-step PCR positive organisms.It found that the zero water exchange strategy could be feasible for the culture of the white shrimp L. vannamei at a commercial level during the fallwinter season

Ecology, Fishery and Aquaculture in Gulf of California, Mexico: Pen Shell Atrina maura (Sowerby, 1835)

The pen shell Atrina maura bears economic importance in northwest Mexico. This chapter considers a review on diverse ecology, fishery, and aquaculture topics of this species, carried out in northwest Mexico. In ecology, biology, abundance, spatial prospecting, sex ratio, size structure, reproductive cycle, first maturity sizes, variation of gonadosomatic indexes and growth are discussed. In fishery, the information analysed corresponds to the structure of the organisms in the banks susceptible to capture, institutional and ecological interaction for fishing regulation, evaluation of fishing effort, improvement in fishing performance using the knowledge and attitudes of the fishermen on fisheries policies in the Gulf of California, resilience and collapse of artisanal fisheries and public politics. In aquaculture, they are long-line culture, bottom culture, reproductive cycle, growth, production of larvae and seeds, biochemistry of oocytes, nutritional quality of the muscle, evaluation of diets based on microalgae, immunology in larval and juvenile and probiotic use. The present work shows a status based on information published in theses and articles indexed 15 years ago to the date on the ecology, fishery and aquaculture in the pen shell Atrina maura carried out in the lagoon systems of northwest Mexico

Effect of white spot syndrome virus (WSSV) and water exchange on survival and production of Litopenaeus vannamei under semi-intensive culture conditions.

A study was performed in two commercial shrimp farms in the province of Guasave, north of Sinaloa, Mexico, to assess the effects of the presence of the white spot syndrome virus (WSSV) and of water exchange on the growth rate, production, and survival of the Pacific white shrimp, Litopenaeus vannamei, during the fall-winter season in semi-intensive culture ponds. The experiment consisted of four treatments; in the first (T1), three earthen ponds with water exchange, were stocked with PCR-positive for white-spot syndrome virus (WSSV) postlarvae. In the second (T2), three earthen ponds were stocked likewise (PCR-positive), but without water exchange. In the third (T3), three earthen ponds, with water exchange were stocked with PCR-negative for white-spot syndrome virus (WSSV) postlarvae. In the fourth (T4), three earthen ponds were stocked likewise (PCR-negative), but without water exchange. The average growth rates were 0.56, 0.56, 0.80, and 0.75 g/week for T1, T2, T3, and T4, respectively. Survival was 23.2% (T1), 26.1% (T2), 64.3% (T3), and 66.1% (T4). Production ranged between 252.60 and 847.00 kg/ha, with the lowest production in T2 and the highest in T3. Feed conversion ratio ranged from 1.00 for T3 to 1.70 for T2. The final average weight ranged between 10.6 g (T2) to 12.5 g (T3). The WSSV can affect negatively the growth rate (30%), the survival (64%), and the production (69%) in comparison with PCR-negative organisms.No differences in weight were found between WSSV-infected and non-infected individual shrimps, as well as in nested-PCR positive against single-step PCR positive organisms.It found that the zero water exchange strategy could be feasible for the culture of the white shrimp L. vannamei at a commercial level during the fallwinter season

Effect of white spot syndrome virus (WSSV) and water exchange on survival and production of Litopenaeus vannamei under semi-intensive culture conditions.

A study was performed in two commercial shrimp farms in the province of Guasave, north of Sinaloa, Mexico, to assess the effects of the presence of the white spot syndrome virus (WSSV) and of water exchange on the growth rate, production, and survival of the Pacific white shrimp, Litopenaeus vannamei, during the fall-winter season in semi-intensive culture ponds. The experiment consisted of four treatments; in the first (T1), three earthen ponds with water exchange, were stocked with PCR-positive for white-spot syndrome virus (WSSV) postlarvae. In the second (T2), three earthen ponds were stocked likewise (PCR-positive), but without water exchange. In the third (T3), three earthen ponds, with water exchange were stocked with PCR-negative for white-spot syndrome virus (WSSV) postlarvae. In the fourth (T4), three earthen ponds were stocked likewise (PCR-negative), but without water exchange. The average growth rates were 0.56, 0.56, 0.80, and 0.75 g/week for T1, T2, T3, and T4, respectively. Survival was 23.2% (T1), 26.1% (T2), 64.3% (T3), and 66.1% (T4). Production ranged between 252.60 and 847.00 kg/ha, with the lowest production in T2 and the highest in T3. Feed conversion ratio ranged from 1.00 for T3 to 1.70 for T2. The final average weight ranged between 10.6 g (T2) to 12.5 g (T3). The WSSV can affect negatively the growth rate (30%), the survival (64%), and the production (69%) in comparison with PCR-negative organisms.No differences in weight were found between WSSV-infected and non-infected individual shrimps, as well as in nested-PCR positive against single-step PCR positive organisms.It found that the zero water exchange strategy could be feasible for the culture of the white shrimp L. vannamei at a commercial level during the fallwinter season

Shrimp aquaculture in low salinity water feeded with worm flavor

Shrimp aquaculture in Sinaloa is one of the top economic enterprises, generating many jobs and earns significant incomes every year. Shrimp feed is an essential part of maintaining healthy production. In this initial approach of shrimp growth in low salinity water, were tested two formulas of animal protein composed of 40% (APL1) and 20% (APL2) worm protein, a commercial diet, and no supplementary feed. Physicochemical parameters did not have a direct influence in shrimpbehavior. After six weeks of experimentation, shrimp fed with commercial diet had a weight gain 20% higher than those feed with worm protein. There were no significantly differences between sizes with respect to 40% animal protein and 20% animal protein with the commercial diet (P  0.05). However, shrimp fed worm protein had lower mortality. The use of worm protein could be an option to maintain a high quantity of shrimp reared in low salinity waters

The endemic region and infection regimes of the White Spot Syndrome virus (WSSV) in shrimp farms in northwestern México

Shrimp farming with a value annually of US$711 million approximately, is one of the most important primary activities in Mexico. However, shrimp farming has had to face various problems that have limited their development, within which the mortality caused by the white spot syndrome virus (WSSV) is the most important. To have scientific elements to focus on preventive health management actions is necessary to know, among other factors, aspects of the epidemiologyof white spot disease (WSD). Therefore this study focused on delimiting the endemic region for WSD and its temporal regimes of infection and discusses possible risk factors related to outbreaks of the disease in shrimp farms of northwestern Mexico. We analyzed information from the databases of the State Committees of Aquaculture Health of Baja California Sur, Sonora, Sinaloa and Nayarit, as well as data of Integrated Program on Shrimp Aquaculture Health (PISA 2007-2008) and the Strategic Alliance Network Aquaculture Industry Innovation (AERI-2008). Data analysis showed that, for the shrimp production cycles of 2007-2008, white spot syndrome virus (WSSV) was endemic to the region of Tuxpan, Nayarit in the south and to Agiabampo, Sonora in the north. Spring outbreaks of WSD in the fishfarms had a spatiotemporal distribution, indicating three infections regimes: (1) March-April in the southern shrimpfarming region (Local Aquaculture Health Boards [LAHBs] of Mazatlan, El Rosario, Escuinapa, Tecuala, and Tuxpan); 2) April-May in the central region (LAHBs of Navolato Norte, Navolato Sur, and El dorado); and (3) May-June in the northern region (LAHBs of Agiabampo-Sonora, Ahome, Guasave Norte and Sur). The WSD were consistent between 2007 and 2008, with slight variations among some LAHBs, with respect to the onset or presence of spring WSD outbreaks. It shows the association of infection regimes throughout the region endemic with the location of Mazatlan,Pescadero and Farallon oceanographic basins according to the increasing differential temperature within them, which may be a determinant factor for the presence of WSD outbreaks