Broodstock development, breeding and larval rearing of Siganus canaliculatus- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Rabbitfishes belong to the family Siganidae include a group of potentially important aquaculture species occurring in the indo pacific, Indian Ocean, Red sea and Eastern Mediterranean regions and are subtropical euryhaline herbivorous fishes. There are 27 species of siganids. In nature, they found in reefs among seagrass, mangroves and in shallow lagoons and algae form a major part of their food. Siganus canaliculatus, an important candidate for aquaculture, has been found to tolerate wide range of salinity (17- 37ppt) in its natural habitat. Though siganids are primarily herbivorous, under captivity the juveniles and adults show omnivorous feeding habits and will accept a variety of foodstuffs viz. vegetable and animal origin as well as pellet feed

Grow out culture of seabass in cages

Aquaculture of Lates calcarifer, known as seabass, was commenced in the 1970s in Thailand, and rapidly spread throughout Southeast Asia. In India also it is a sought after fish in many states. The grow-out phase involves the rearing of the seabass from juvenile to marketable size. Marketable size requirement of seabass vary country to country e.g. in Malaysia, Thailand, Hong Kong and Singapore, the normally accepted marketable size of seabass is between 700–1200 g while in the Philippines, marketable size is between 300–400 g. The culture period in grow-out phase also vary from 3–4 months (to produce 300–400) to 8–12 months. The success of marine cage culture of seabass and its economical viability have contributed significantly to large scale development of this aquaculture syste

Abalone culture- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Abalones, commonly known as ear shell are economically important marine gastropods belonging to the genus Haliotis. There are about 100 species of the abalones in the world. Abalone occur in all major oceans of the world but they appear to be more abundant in the temperate zone. Large abalones are mainly distributed in the temperate zone, while small specimens are typically found in topics and the cold zone. The body of abalone is divided into three parts: head, foot and saccate intestine. Head is located on the anterior pat of the body and comprises a mouth, appendages and sensory organs. It has a pair of tentacles and two eyes at the tip of eyestalk, which originates at the bottom of the tentacles. Foot of the abalone is a creeping organ of muscular tissue, which lies on the ventral pat of the body. The well-developed foot has a broad sole, which allows the animal to strongly adhere to rocks and other had substrate

Cage launching in Ashtamudi, Kollam

Cage launching in Ashtamudi, Kolla

Art of keeping marine aquarium

Bringing a small section of the marine environment to your home sounds like a difficult task. But it is being done by more and more by the average aquarist, who wants to try this difficult task. Tremendous progress has been made in the keeping of the marine fish over the past decade. Much knowledge has been acquired and many new products have entered market to facilitate the keeping of marine fis

Principles and practices of cage mooring

Moorings are required to hold cages against the forces generated by wind, currents and waves and to allow the fish stocks and the cages and let the best chance of survival. In sheltered waters, requirements to moor a cage safely were minimal. This has changed dramatically with moves into coastal waters, and a potentially much higher wave climate. Mooring failures were common place in the early days of coastal farming, but a better understanding of the problems, and more sophisticated analysis has largely reduced these risks. Perhaps the most important point is to view the cage group, its nets and moorings, as a single system, whose components are mechanically linked. Their dynamic responses cannot be considered in isolation, each component affecting the other. Cage and mooring design is “site specific”, and careful and combined choice of cage type, nets and most specifically moorings, has a considerable bearing on the ability of fish stocks to survive in major storms, on exposed sites

Aeration, Filtration and Disinfection in Mariculture

Among various water quality parameters for a successful aquaculture practice, Dissolved oxygen content in the water is one of the most important parameters, as the oxygen is a vital for all the organisms living in the water and having an aerobic type of respiration. The purpose of aeration is to increase the concentration of oxygen in the water. In scientific aquaculture practices, this is more critical because, often the rate of consumption of oxygen is much higher than the natural rate of replenishment of oxygen in the water through diffusion from atmosphere and photosynthesis of aquatic plants. Oxygen is one environmental parameter that exerts a tremendous effect on growth and production through its direct effect on feed consumption and metabolism and its indirect effect on environmental conditions. Oxygen affects the solubility and availability of many nutrients. Low levels of dissolved oxygen can cause changes in oxidation state of substances from the oxidized to the reduced form. Lack of dissolved oxygen can be directly harmful to culture organisms or cause a substantial increase in the level of toxic metabolites. It is therefore important to continuously maintain dissolved oxygen at optimum levels of above 3.5 ppm

Cage Aquaculture

Today cage culture is receiving more attention by both researchers and commercial producers. Factors such as increasing consumption of fish, some declining wild fish stocks, and a poor farm economy have produced a strong interest in fish production in cages. Many small or limited resource farmers are looking for alternatives to traditional agricultural crops. Aquaculture appears to be a rapidly expanding industry and one that may offer opportunities even on a small scale. Cage culture also offers the farmer a chance to utilize existing water resources which in most cases have only limited use for other purposes

Embryonic development in Octopus aegina Gray, 1849

Cephalopods occur in all marine habits of the world. They are extremely important in ecological, biological and biomedical research. The genus Octopus consists of more than 100 species and along with Sepia sp. and Sepiella sp. accounts for about 50% of all described cephalopods. Octopus earns valuable foreign exchange for the country. Knowledge on the embryonic and larval development is essential for hatchery and culture techniques. Development stages of the embryo were sequenced based on morphological characters. During the course of development, the embryo reverses its position two times; the new born resembles adults in form except for its free-swimming mode of life. The gestation period of the embryo was 18 to 20 days at a temperature range of 28–30°C

Souvenir : 5th International Symposium on Cage Aquaculture in Asia

This souvenir is a compilation of invited manuscripts distilling lessons learnt over decades of cumulative experience in marine and inland cage farming, breeding and seed production, nutrition, health and environment management, legislation and policy issues. I congratulate the organisers of the Symposium for facilitating this exchange of knowledge and ideas. I also thank the contributors for giving freely of their time and expertise