201 research outputs found
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 700тАУ1200 g while in the Philippines,
marketable size is between 300тАУ400 g. The culture period
in grow-out phase also vary from 3тАУ4 months (to produce
300тАУ400) to 8тАУ12 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
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 тАЬsite specificтАЭ, 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 28тАУ30┬░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
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