Heavy landings of juveniles of Indian scad, Decapterus russelli at Munambam Fisheries Harbour

Among the carangid fishes, the Indian scad, Decapterus russelli is an important pelagic fish and a major commercial species contributing to the marine fisheries of Kerala. The fish is locally called “kozhuchala” and it forms a regular fishery. The species is often caught as by-catch in shrimp trawl nets having cod-end mesh sizes ranging from 15 mm to 20 mm that is operated in the depth range of 55- 90 m almost throughout the year. They are consumed fresh as well as sun dried form

Culture and breeding of Archocentrus spilurum at Tuticorin District of Tamil Nadu, India

Blue eyes, Archocentrus spilurum is a Central American fish species. It is considered a relatively peaceful cichlid and it is not very fussy when it comes to water conditions and temperature. Among the cichlids, blue eyes are suitable for community tank because of its peaceful nature. It may not be the most colorful, but they are very pretty little fish and their blue eyes set them apart from other cichlids. In nature it prefers shallow areas with sand, mud and rock substrates as well as slow moving waters of the lower riverine valley areas. Hence, vigorous water movements are not necessary in the aquarium. It inhabits the middle and bottom regions of the tank

Copepod Abundance and Diversity from Offshore Region of Tuticorin, South East Coast of India

A detailed study had been carried out on species abundance, biomass and composition of copepod in four different offshore stations namely, Station I: Vembar, II: Keelavaipar, III: Punnaikayal and IV: Thiruchendhur in Gulf of Mannar region from October 2011 to April 2012. A total of 56 copepod species belongs to 20 families under 4 orders have been encountered during the period. The percentage composition of different groups of copepod species was composed of Calanoida (35 numbers) 62.5%, Cyclopoida (4 numbers) 7.14%, Harpacticoida (8 numbers) 14.3% and Poecilostomatoida (9 numbers) 16.1%. The percentage of biomass composition of different groups of copepods during the study was in the order of Calanoida 38.99%, Harpacticoida 32.56%, Cyclopoida 15.22% and Poecilostomatoida 13.23%. In the case of species composition, Euterpina acutifrons (28.61%) was the most abundant species followed by Acrocalanus gracilis (17.68%), Corycaeus crassiusculus (12.33%), Oithona brevicornis (12.03%) and Temora turbinata (4.25%) were the other dominant species in observation. The copepod density in different stations were in the range of 8600–39900, 3900–64600, 3800–24800 and 5000–22500 numbers m-3 at station I, II, II and IV respectively. The lowest biomass of copepod was observed at station III and highest biomass was found at station II. The copepod species richness ranged from 0.48 to 2.72 and species diversity was in the range of 0.87 to 1.98 in the study areas. Species evenness was varied from 0.24 – 0.51 during the observation period

Adoption of Sea Cage, Culture Practices in Thoothukudi District Tamil Nadu: An Eye Opener for Income Generation

Adoption of Sea Cage, Culture Practices in Thoothukudi District Tamil Nadu: An Eye Opener for Income Generatio

ELECTROCHEMICAL DETERMINATION OF NITRO EXPLOSIVE (HNS) USING GLASSY CARBON ELECTRODE

A glassy carbon electrode (GC) exhibited an attractive performance for the detection and determination of a nitro compound like 1,2- Bis(2,4,6-trinitrophenyl)ethylene (HNS). Cyclic voltammetry, differential pulse and square wave voltammetry were used in a combined way to identify the electrochemical characteristics and to optimize the conditions for detection. For calibrating and estimating HNS, square- wave voltammetry was mainly used. The HNS shows a well-defined peak at in the dimethy sulfoxide (DMSO) containing Tetrabutyl Ammonium Bromide (TBABr) medium. The existence of peak at -0.10 V showed good peak and high current response

Captive breeding, spawning, embryonic and larval development in Horse conch, Pleuroploca trapezium (Linnaeus, 1758) from Southeast coast of India

Captive breeding, spawning and larval development of endangered gastropod, horse conch, Pleuroploca trapezium (Linnaeus, 1758) was studied and reported from Thoothukudi, Southeast coast of India for the first time. Wild collected brooders of P. trapezium were spawned after 10 months of rearing under captivity as a cluster of egg cases on the wall of the tank and also above the shell of the other horse conch. Each egg case had 150 to 460 numbers of eggs. The incubation period ranged from 23 to 30 days and 91 % of hatching was recorded. Detailed observations were made on the embryonic development and larval rearing until 40 days of post hatch (dph). The day one larvae measured 750±14.15 μm and reached an average shell size of 1830±37.48 µm after 40 dph. After 30 dph, though most of the pre-juveniles settled and crawled at the bottom of the rearing tank, the presence of active velum indicated that the competency to metamorphosis for the development of juvenile was not fully attained and complete mortality occurred. Therefore, further study is warranted using different cues to promote the metamorphosis of Pleuroploca trapezium for successful life cycle closing and juvenile production

On captive breeding, spawning, embryonic and larval development in Horse conch, Pleuroploca trapezium (Linnaeus, 1758) from Southeast coast of India

Captive breeding, spawning and larval development of endangered gastropod, horse conch, Pleuroploca trapezium (Linnaeus, 1758) was studied and reported from Thoothukudi, Southeast coast of India for the first time. Wild collected brooders of P. trapezium were spawned after 10 months of rearing under captivity as a cluster of egg cases on the wall of the tank and also above the shell of the other horse conch. Each egg case had 150 to 460 numbers of eggs. The incubation period ranged from 23 to 30 days and 91 % of hatching was recorded. Detailed observations were made on the embryonic development and larval rearing until 40 days of post hatch (dph). The day one larvae measured 750±14.15 μm and reached an average shell size of 1830±37.48 µm after 40 dph. After 30 dph, though most of the pre-juveniles settled and crawled at the bottom of the rearing tank, the presence of active velum indicated that the competency to metamorphosis for the development of juvenile was not fully attained and complete mortality occurred. Therefore, further study is warranted using different cues to promote the metamorphosis of Pleuroploca trapezium for successful life cycle closing and juvenile production

On captive breeding, spawning, embryonic and larval development in Horse conch, Pleuroploca trapezium (Linnaeus, 1758) from Southeast coast of India

795-801Captive breeding, spawning and larval development of endangered gastropod, horse conch, Pleuroploca trapezium (Linnaeus, 1758) was studied and reported from Thoothukudi, Southeast coast of India for the first time. Wild collected brooders of P. trapezium were spawned after 10 months of rearing under captivity as a cluster of egg cases on the wall of the tank and also above the shell of the other horse conch. Each egg case had 150 to 460 numbers of eggs. The incubation period ranged from 23 to 30 days and 91 % of hatching was recorded. Detailed observations were made on the embryonic development and larval rearing until 40 days of post hatch (dph). The day one larvae measured 750±14.15 μm and reached an average shell size of 1830±37.48 μm after 40 dph. After 30 dph, though most of the pre-juveniles settled and crawled at the bottom of the rearing tank, the presence of active velum indicated that the competency to metamorphosis for the development of juvenile was not fully attained and complete mortality occurred. Therefore, further study is warranted using different cues to promote the metamorphosis of Pleuroploca trapezium for successful life cycle closing and juvenile production

Effect of lime, dolomite and gypsum on phosphorous reduction potential in freshwater

A fifteen days experiment was conducted with the application of different agrochemicals such as lime, dolomite and gypsum in two levels to find out the phosphorous reduction potential of these chemicals at laboratory. Among the 3 agrochemicals gypsum showed better phosphorous reduction at the dose of 40 mg/L followed by dolomite had comparatively high phosphorous reduction than lime application. The water quality parameters indicates that application of these chemicals at the rate of 20 and 40 mg/L dose level did not produce any adverse condition on the pH, alkalinity and hardness values. Hence, application of gypsum at the rate of 40 mg/L is recommended for use in aquaculture ponds to reduce the phosphorous load in the wate

Incidence of amyloodiniosis in snubnose pompano juveniles and its effective control in marine hatchery

Amyloodiniosis infection in snubnose pompano was reported in marine fish hatcheries of ICAR-CMFRI during preparation for certain feeding experiments in this fish that is of aquaculture importance. The control and elimination of Amyloodinium sp. from the hatchery system is a herculean but vital task and several methods were carried out following the infection.These were evaluated for their usefulness and are reported below