Marcia opima (Gmelin, 1791)

Marcia opima has a small, glossy, puffed-up shell which ranges from a creamish-brown to grey colour. There are radial dark markings on the shell running from the umbo to the shell margin. Inner surface of the shell is white. Hinge has three teeth and a long ligament. Anterior lateral teeth is absent in left valve, but corresponding depression is present on the right valve

Crassostrea madrasensis (Preston, 1916)*

The Indian backwater oyster is an irregularly shaped oyster with straight shells. The shell has a deep left valve and concave right valve. The hinge which joins the shells is narrow and long. The animal has a right and left mantle lobe which encloses the mantle cavity which in turn encloses the rest of the organs

Microalgae culture media and glass ware

Microalgae culture with desired species of flagellates or diatoms is the basis of any finfish or shell fish larval rearing and culture system. Natural sea water is a complex culture medium containing more elements and organic compounds, and which supports mixture of all phytoplankton and zooplankton. But in the laboratory culture, monospecies culture of micro algae is being maintained to support different culture requirements. Natural sea water with added nutrients is recommended, because direct sea water may not provide the optimum nutritional requirement of specific algae. So enrichment of natural sea water is necessary with the addition of macro nutrients, micro nutrients, trace elements and vitamins. Each micro alga needs the specific culture media, with basic nutrients like nitrogen, phosphorous, vitamins and trace metals for better growth and multiplication

Perna indica (Kuriakose & Nair, 1976)*

Brown mussels as the name suggests have brown coloured shells. They have elongate, equivalved and equilateral shells with pointed and straight anterior end. Dorsal ligamental margin and ventral shell margin are straight. The two valves of the shell are hinged at the anterior end with terminal umbo. Interior of shell is lustrous with muscle scar deeply impressed. It has a finger shaped, thick and extensible foot

Perna viridis (Linnaeus, 1758)

Perna viridis is characterised by an elongate shell with pointed and swollen anterior end and a compressed posterior end. Umbo is tapering sharply at the terminal. Ventral margin is concave and long, whereas anterior margin is reduced. Outer surface possesses concentric growth marks and faint radial lines. The smooth periostracum (outer shell) is thick and dark green, with finely pitted ligamental ridge

Selection of candidate species for cage culture in India

In recent years, cage culture has emerged as one of the most viable method of sea farming. This aquaculture farming system offers the farmer a chance to utilize existing water resources, which is not used for other purposes. At present, situations like increase in consumption of fish, decline in wild stock and poor return from other culture systems paved strong interest for the fish production through cage culture among the fish farmers. Selection of fish species is playing major role in cage culture operation. Therefore, while selecting the species the biological as well as economical criteria should be taken into consideration, which includes available source of fish seed either from wild or hatcheries, seasonal abundance of the fish seeds in wild, acceptance to artificial feeds, consumer acceptance to the fish, economic value of the fish in local and international market, regional preference, compatibility of the species to culture in various system, resistance to disease and stress, ability to breed and produce the seed in confined environments. By considering the above criteria, a variety of commercially important marine fish species are highly found suitable for cage farming. The important candidate species from different parts of the world includes cobia (Rachycentron canadum), seabass (Lates calcarifer), snappers (Lutjanus sp.), pompanos (Trachinotus sp.) and groupers (Epinephelus sp.), etc. Commercial level seed production technology for majority of these fishes has been developed in many of the South East Asian countries. In India, the seed production of cobia, silver pompano, seabass and orange spotted grouper has been achieved successfully by different fisheries research institutions

Training Manual on Cage Culture of Marine Finfishes 7-12 November, 2016

Training manual on “Cage Culture of Marine Finfishes” is published by the Central Marine Fisheries Research Institute, Visakhapatnam Regional Centre, Andhra Pradesh under finance assistance from All India Network Project on Mariculture (AINP-M), ICAR. This manual is published as reading material in the training programme on cage culture of marine finfishes held during 7-12th November, 2016 for fishermen, aquafarmers and entrepreneurs involved in mariculture activities. This manual is consisting of different chapters which describe various aspects related to open sea cages

Labroides dimidiatus (Valenciennes, 1839)

Blue streak cleaner wrasse is one of the most important and popular species of ornamental fish widely distributed in the natural waters of tropical countries. It is commercially valuable both as ornamental fish and for controlling ectoparasites. These are small fishes of about 9- 14 cm size with blue to yellow colour dorsally, fading to white or yellow ventrally. There is a black stripe running from the eye to the caudal fin margin which widens posteriorly

Live feed for marine finfish and shellfish culture

Live food organisms include all plants (phytoplankton) and animals (zooplankton) which are used in finfish and shellfish larval rearing system. Live foods are able to swim in water column and are available to fish and shellfish larvae thereby stimulate the feeding response (David 2003). In nature, most of the finfish and shellfish larvae feed on small phytoplanktonic and zooplanktonic organisms. Phytoplankton comprises the base of the food chain in the marine environment. Micro algae have an important role in aquaculture as a means of enriching zooplankton for feeding fish and other larvae. In addition to providing protein (essential amino acids) and energy, they provide other key nutrients such as vitamins, essential poly unsaturated fatty acids (PUFA), pigments and sterols, which are transferred through food chain. Zooplankton forms the primary food for fish larvae. The dominant zooplankton groups are rotifers and copepods. These groups are the preferred prey for shrimp and fish larvae and are the most widely used live feeds by aquaculturists. The intensive larval culture of most marine fish depends on large supply of zooplankton

Social factors induces sex change in Orange spotted grouper, Epinephelus coioides

Sex change (sequential hermaphroditism) is a normal part of the life history of many species of tropical coral reef fishes. Sex change can be either from male to female (protandrous) or it can be from female to male (protogynous). In the family Serranidae, protogynous hermaphroditism is the most common reproductive pattern. However, Orange spotted grouper is diandric, i.e., they have two types of male: Primary males which are gonochorous (non sex changers) often with initial phase; and Secondary males which are derived from female to male initial phase