Survival, maturation, fecundity and hatching rates of unablated and ablated Penaeus indicus H.M. Edwards from brackishwater ponds

Penaeus indicus harvested after three months of rearing in brackishwater ponds and averaging 6.9 g for females and 5.6 g for males were stocked in two 12 cu m flowthrough ferrocement tanks at 240 females and 200 males per tank. The females were ablated on one eyestalk in one tank and remained unablated in the other tank; all males were unablated. Ablated females spawned up to 7 times per female; unablated females spawned up to only 3 times during the two month duration of the experiment. Ablated females produced a total number of 17.5 x 10⁶ eggs, 6.6 x 10⁶ nauplii, and an average of 23,480 eggs/spawning and 37.8% hatching rate from a total of 757 spawnings. Unablated females produced a total of 2.0 x 10⁶ eggs, 1.1 x 10⁶ nauplii, and an average of 26.990 eggs/spawning and 53.9% hatching rate from a total of 74 spawnings. Survival of ablated females was 53.5% compared to 69.4% for unablated females; males in both tanks averaged more than 90% survival.

Catch composition of penaeid prawns caught with fish corrals at Batan Bay, Philippines

The study was undertaken to ascertain the commercially important species of penaeid prawns caught in Batan Bay, Philippines and their abundance in fish corrals. A total of 12 species were commercially caught: Penaeus monodon, P. semisulcatus, P. merguiensis, P. indicus, P. latisulcatus, P. japonicus, P. canaliculatus, Metapenaeus ensis, M. endeavouri, M. dalli, M. elegans, and Trachypenaeus fulvus.

Viability of frozen algae used as food for larval penaeids

Freezing with added chemicals as flocculants and protectants was assessed as a means of preserving stock cultures of 4 algal species used for larval penaeid food Chaetoceros calcitrans, Skeletonema costatum, Tetraselmis chuii and Isochrysis galbana. The maximum storage effectability of the preservation techniques for each species was also determined.

Shrimp pond culture in the Philippines

The document reviews and evaluates the development of shrimp culture in the Philippines. It also discusses the ecological and socioeconomic effects of shrimp culture industry in the country.

Shrimp culture and the environment

The paper discusses the impacts of shrimp culture to the environment in some countries in Asia. Specifically, it highlights the land requirements suitable for shrimp farming and the impacts of shrimp culture on mangroves. The positive effects of mangroves such as its filtering capacity and as a protective buffer are also discussed.

Mangroves to aquaculture

The paper discusses the recommended strategies regarding the further conversion of mangrove forests to fishponds and the management of existing fishponds for the culture of various aquatic species based on economic feasibility analysis. Strategy for the management of Philippine mangrove and the guidelines for the selection of mangrove areas for preservation, conservation and fishpond development are also presented.

What needs to be done?: Guide in mangrove reforestation

The article presents a two-part guideline in mangrove reforestation. The first part is zonation, which is the process of determining what species are particularly suited to plant in a particular site. While, plantation establishment is the second part, it includes guides in the identification of species, selection of planting site, preparation of the planting sites, seed collection, handling and transporting of seeds, and planting.

Beginnings: SEAFDEC/AQD, CFRM, and Malalison Island

The paper documents the community fishery resources management activities of Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD) in Malalison Island, Antique, Philippines.

CRM in the Philippines: Lessons learned

Philippine coastal communities can become capable fishery resource managers and that their management practices can become largely self-sustaining if the project approach focuses on assisting fishermen to learn how to help themselves. Community organization is an essential part of the process and should not be viewed as an end product in itself. There are also no quick fixes, and projects require a complex array of activities if large numbers of coastal residents are to be assisted. In some of these projects, the control of illegal fishing combined with limiting of commercial fishing to offshore areas and good coastal habitat management resulted in a doubling of daily fish catch and income for small-scale fishermen. However, even with the best of management, the total fishery harvest is limited and further increases in individual fishing income can only come from reducing total fishing effort. This will require a system of control on access to the resource to limit the number and kind of fishing gears and to divide the resource equitably. Assisting coastal communities to devise and implement realistic equitable access controls is the major challenge facing coastal resource co-management.

Quo vadis, shrimp?

The paper discusses the shrimp culture practices of Thailand, the top producing country of cultured shrimp. These shrimp culture techniques include the use of reservoirs for better waste management, utilization of undiluted seawater for culture, low-cost pumping systems, measures to neutralize acid sulfate soils, proper treatment of pond bottom, and solutions to disease problems.

Pathogens after shrimp: A rogue's gallery of the industry's four most destructive adversaries

The paper discusses the four most destructive shrimp pathogens, such as MBV, the monodon baculovisrus, IHHNV, the infectious hypodermal and hematopoietic necrosis virus, Vibrio harveyi, the luminous bacteria, and WSBV, the white spot syndrome-associated baculovirus. The effects, detection method and treatment for the four pathogens were also briefly discussed.

Go slow, check your technology

The paper presents the outlooks and experiences of veteran shrimp farmers from Negros, west central Philippines after its collapse in the late 1980s due to the luminous bacteria.

Using bacteria to fight bacteria

The paper discusses about probiotics and its possible use in shrimp aquaculture. The paper also provides information on how the probiotics work and presents the preliminary results of the field tests conducted by Southeast Asian Fisheries Development Center, Aquaculture Department and BIOPOND Systems. The general characteristics of Bacillus are also discussed.

The trouble with antibiotics and pesticides is...

The paper discusses the output of the meeting on the use of chemicals in aquaculture in Asia. The effects of chemical use on cultured stocks in the farm, the immediate environment through discharges and effluents, surrounding areas, farm staff, consumers and drug resistance organisms are also discussed. It also shows how an antibiotic-resistant microorganism develops as the result of indiscriminate use of antibiotics.

Glucans and disease resistance

The paper presents the usefulness of beta-glucans as immunostimulants for strengthening the non-specific defense system of a wide range of animals. In Taiwan, researchers tested the effects of beta-glucans on the vibriosis resistance of tiger shrimp Penaeus monodon which yield promising results. They suggest that supplementation of beta-glucan at 0.5 mg per ml is sufficient in strengthening the non-specific defense mechanism of postlarval shrimp.