Aquaculture Asia Magazine, January-March 2021

Coral trout Plectropomus leopardus is an emerging exported grouper commodity in Indonesia. The demand for coral trout fingerlings has been increasing and the value of this species is the highest among groupers. However, the rearing of coral trout larvae is notoriously more ‘difficult’ than other groupers. This article describes research on coral trout larval rearing protocols conducted by the Institute for Mariculture Research and Fisheries Extension, which has achieved a survival rate of 12%.

In retail fish markets in Kolkata city proper, suburbs and neighbouring districts, pituitary glands are collected as a profession from the heads of mature fish. The preserved glands are used to induce breeding via hypophysation in carp hatcheries throughout West Bengal, playing an important role in the availability of carp seed to support aquaculture operations. This article describes the livelihoods of pituitary gland collectors and traders in West Bengal, India.

Feed is an important input that involves nearly 60% of the total production cost in commercial aquaculture. Hence, nutritionally balanced and cost-effective diets play a large role in deciding the return from an aquaculture venture. Nutritionists are searching for alternative ingredients and approaches to offset the use of fishmeal in aquaculture feeds. This article discusses strategies to reduce feed cost by promoting gut health and nutrient utlilisation, including: Use of probiotics and prebiotics,  supplementation with exogenous enzymes, essential nutrients and chemoattractants, and use of other feed additives such as acidifiers to improve digestibility and mycotoxin binders.

Clarias magur, locally known as magur, is a well-preferred medium sized catfish among Indian consumers. Difficulties such as shortages of effective inducing agents and the erratic response to induced breeding, low survival in different life stages, slow growth, and lack of effective feeds have been a bottleneck for the wider adoption of this fish by farmers. There has been considerable research to simplify the technology and disseminate it among farmers over the last decade. This article summarises these attempts and describes the present level of its technology practiced in India.

The Shrimp Farming BD App contains information on improved technologies - from pond preparation through to harvest - and has a calculator that farmers can use to work out the quantities of chemicals, feeds and other inputs they need for their pond. Also incorporated is a Frequently Asked Questions (FAQ) page where users can find answers to common questions with a single click: and they can send specific technical questions to SAFETI specialists online and receive an answer back within hours. The app can also be used to post news messages, and a link to market prices is planned. 

Commercial trout farming in Uttarakhand has advanced progressively during the last decade and has become a profitable occupation among the rural masses especially in the colder regimes where no other fish farming has possibilities. The rainbow trout here plays the most dominant role as a commercially important candidate species for culture in this hill locked Himalayan state of India. This article describes the current status of trout fisheries resources and trout aquaculture in Uttarakhand, and their potential further development.