Gabriel Aguirre-Guzmán

The use of probiotics in aquatic organisms: A review

The production of aquatic organisms for human consumption has been decreasing while its demand has increased. The decline of fish products from fisheries has been in part compensated by the aquaculture industry. The need for enhanced disease resistance, feed efficiency, growth performance and lower production costs of cultured organisms is substantial for various sectors of this industry. Different products have been used at some extent to prevent disease and as growth promoters; however, their inadequate application can create adverse disorders, environmental imbalances, and increase predisposition to disease. In the search of new disease control and prevention options, several studies have been carried out to test some functional additives (probiotics). Probiotics have been shown to improve energy expenditure derived from sources such as carbohydrates and increase the incorporation of protein for growth; and to increase the immunity and disease resistance of the host. The use of probiotics in aquaculture has high potential application at a commercial level; however, it has been poorly characterized and studied. This study aims to review the use and action of probiotics in the culture of aquatic organisms (bivalve, fish, shrimp); and the potential for further application of this in aquaculture production.

Distribution of Farfantepenaeus aztecus and F. duorarum on submerged aquatic vegetation habitats along a subtropical coastal lagoon (Laguna Madre, Mexico)

The spatial distribution of Farfantepenaeus shrimp was analysed in the Laguna Madre of Tamaulipas, Mexico. Sampling was carried out on submerged aquatic vegetation (SAV) habitats at five sites located along the coastal lagoon. Two nocturnal surveys were conducted during winter in 2005 (January–February), collecting a total of 3268 shrimp individuals. SAV beds were composed of a mixture of drift algae (mainly Digenia simplex ), attached algae (mainly Penicillus capitatus and Udotea occidentalis ) and seagrass (mainly Halodule wrightii ). Farfantepenaeus aztecus was more abundant (39.5%) than F. duorarum (36.8%), and the remaining 23.7% corresponding to small unidentified Farfantepenaeus spp. were classified as recruits. Abundance of F. aztecus was significantly higher at sites 2 and 4, whereas F. duorarum did not show significant distribution differences along the Laguna Madre. Recruits, juveniles and total shrimp tended to decrease significantly at the northern part of the lagoon (site 1), where substrate was dominated by drifting algae and seagrasses were scarce or absent. The abundance of shrimp was positively related to seagrass biomass and/or water temperature, whereas there was a negligible or negative relationship with algal biomass. With the exception of subadults, a significant positive linear relationship between seagrass and shrimp abundance was fitted, indicating an increase in number of individuals of both species with increasing seagrass biomass. This suggests that seagrass is the most important component of SAV beds influencing the abundance of F. aztecus and F. duorarum along this hypersaline coastal lagoon.

White Spot Syndrome Virus (WSSV) and Necrotizing Hepatopancreatitis (NHP) detection in wild shrimp of the San Andrés Lagoon, Mexico

The presence of diseases caused by virus and bacteria pose a threat to the capture and commercialization of shrimp, and may cause significant economic damage. Nocturnal monthly sampling were conducted to detect the presence of IHHNV, WSSV, and NHP in San Andres Lagoon in Tamaulipas, Mexico, an important coastal ecosystem due to its shrimp fishery and the existence of shrimp farms in the area. Polymerase chain reaction (PCR) analysis in the shrimp tissue did not detect the presence of IHHNV, however, WSSV was detected, as well as NHP during July and August, when low salinities and high temperatures were recorded.

Interaction of Fisheries and Aquaculture in the Production of Marine Resources: Advances and Perspectives in Mexico

Marine capture fisheries in Mexico are dominated by sardine, shrimp, and tuna, representing as a whole 60 % of the total catch. However, shrimp and tuna are the most important fishery resources in terms of economic value. Capture shrimp fishery in Mexico has exhibited stagnating catches (around 65 thousand tonnes) since the last two decades, and shrimp stocks have been clearly depleted in some parts of the country. Conversely, shrimp (Litopenaeus vannamei) aquaculture has shown an exponential growth in the number of farms and shrimp production since mid-1980s. As a result, currently, shrimp aquaculture production has almost doubled the total production of the capture shrimp fishery. On the other hand, total catch of tuna by Mexican tuna fleet has fluctuated around 130 thousand tonnes during the last 5 years (2007–2011). Contribution of farmed tuna (Thunnus orientalis) has been negligible in terms of volume; however, the price of 1 tonne of farmed tuna is about 7–13 times that of tuna caught by the fishing fleet, making it an attractive alternative as source of employment and income. The case studies presented here are indicative of the potential value of aquaculture as a complementary productive activity to meet the growing human demand for food from the sea. This is especially relevant in terms of global fisheries production because the maximum fisheries catch potential from the oceans around the world has apparently been reached. However, there are still concerns associated with aquaculture impacts on the environment that must be addressed.