Brief note on infestation of Diplectanum sp. in Asian seabass

Recently open sea cage farming has emerged as an alternative and additional income source for fishermen and fish farmers in India. Asian seabass, Lates calcarifer is widely used in open sea cage culture due to its high market demand. In cage farming, high stocking densities and poor water quality enhance the parasite loads of the cultured fishes. In this study, 47 specimens of Asian seabass collected from cages located in Naganathwada, Sunkeri, Ankola were analysed with the aim of identifying the parasites prevalent among this species. All external and internal organs of each fish were examined separately under microscope for parasites. The collected monogenean parasites were washed in a 0.85% saline solution and fixed in 70% ethanol and identified. Most of the infected fishes had dark coloration of the body and postmortem findings revealed gills with excessive mucus secretion and sticking of the gill tips with greyish coloration

Argulus quadristriatus infestation in cage cultured Asian seabass

In Indian waters, genus Netuma is represented by two species namely N. bilineata and N. thalassina (Order: Siluriformes, Family: Ariidae). Rounded shout, thin lips, inconspicuous median longitudinal groove, and higher anal fin ray count (16-19) are characters of N. bilineata while N. thalassina has conical snout, clearly visible median longitudinal groove and lower anal fin ray count (13-15). Prior to the erection of N. bilineata (earlier considered as synonym of N. thalassina) as valid species, Indian workers had difference of opinion regarding the representation of species under this genus from Indian waters

Evaluation of suitable sites for mud crab farming in Ratnagiri District of Maharashtra, India

The State of Maharashtra has vast stretches of estuaries, creeks and mangrove swamps, which offers great potential for aquaculture, particularly for mud crab farming. In view of the natural resources and market potential for mud crab, the Department of Forests, Government of Maharashtra plans to promote mud crab farming through a novel approach, which aims at providing livelihood support to the local communities utilizing the mangrove wetlands; thereby the local communities also shoulder the responsibility of conservation of mangroves. In this backdrop, a study was conducted to identify the suitable sites for sustainable mud crab culture, in GIS environment, based on various physical and environmental criteria including topography, soil types, landuse systems, vegetation, water quality, water availability, salinity, risks of flooding, infrastructure, seed resources and availability, market and support services. The brackishwater stretches of Anjarle, Kelshi, Aade, Velas and Ansure in the Ratnagiri district of Maharashtra were studied, and all study stations had patchy to thick mangrove vegetation. The major mangrove species encountered were: Avicennia marina, Avicennia officinalis, Sonneratia caseolaris, Rhizophora mucronata and Acanthus ilicifolius. The pH of water was near-neutral to alkaline, whereas dissolved oxygen levels were found to be within the ideal range. The salinity of the tidal creeks ranged from 7.24 ppt (Velas) to 35.9 ppt (Ansure) which generally varies with the tide. The ammonia levels which ranged from 0 (Aade and Ansure) to 0.5 ppm (Kelshi), falls within the safe levels for Available online at: www.mbai.org.in doi: 10.6024/jmbai.2017.59.2.2014-05 aquaculture. The sediment pH ranged from 6.2 to 8.32. The organic carbon levels in sediment ranged from 0.27 to 2.94% indicating medium to high productive nature of sediment. Samples of mud crab collected from the study areas were processed for screening for WSSV infection. All samples gave Negative results in primary as well as nested PCRs, indicating the absence of WSSV in the wild mud crab population. Integrating the analysis result along with supporting spatial data with the aid of GIS and Remote Sensing techniques, a total of 10.063 ha have been evaluated as suitable areas for mud crab farming along the brackishwater stretches of Anjarle (1.91 ha), Aade (2.069 ha), Kelshi (1.77 ha), Velas (0.538 ha) and Ansure (3.776 ha)

Marine Ecosystem Challenges & Opportunities (MECOS 3)

The Marine Biological Association of India (MBAI), established in 1958, is proud to gear up for MECOS3, the third symposium on Marine Ecosystems- Challenges and Opportunities during 7-10 January, 2020. The MBAI besides organising MECOS1 (2009) and MECOS2 (2014) has inculcated active interest and participation among its members by handling several national and international symposia/seminars, since its formation. The MBAI has 794 life members and 20 institutional members. The mandate of the MBAI is promotion of scientific research in the field of marine biology and allied sciences

Biotechnological approaches in Fishery Management

There had been tremendous advances in molecular technology, genomics and biotechnology over the last few decades and the scope of its application in fishery resource management and aquaculture is enormous. The oceans bestow immense resources for research and development and these needs to be conserved for long term sustainability. Fish is the major source of protein for over a billion people, and biotechnology offers a „give and take management system‟ whereby biotechnological tools can be used for conservation of ocean resources as well as for sustainable exploitation and utilization of the resources. Responsible fishery management aims to bring about sustainability by adopting an ecosystem approach to fisheries. Biotechnological tools can be effectively utilized to bring about sustainability of the marine ecosystems in many different ways. Again, aquaculture contributes about 41% of the total fish production, (63.6 million tonnes of fish and shellfish annually, FAO, 2012), and is the world‟s fastest growing food production sector, technological challenge in the aquaculture production and sustainability could also be met through biotechnological innovations

Innovative "Microsate" Cage Culture Systems for Livelihood and Nutritional Security: A Participatory Approach

Aquaculture is the fastest-growing food production sector in the world and is considered to be of vital importance for the livelihood and nutritional security. Here we describe an innovative “Microsate” cage fish culture model for alternative income generation and livelihood security of inland fisherfolks. The “Microsate” were implemented in the Vembanad lake close to Azhikode bar mouth along the West coast of India. The programme implementation have processes such as stakeholder selection, site selection, fabrication of cages, monitoring the culture process, harvesting and marketing of the fish. The selected male and female stakeholders members were trained for “Microsate” fabrication and rearing of the fish. Hatchery reared Asian seabass (Lates calcarifer) and indigenous Pearl spot (Etroplus suratensis) fingerlings were stocked in the cages. They were fed with pellet feed as well as trash fish at dawn and dusk period. After the seven months of “Microsate” culture, plate size fishes were harvested and sold out in the domestic market with premium price. The income generated equally divided among the members which was used for the second culture. The newly developed, ecofriendly microsate cage culture model can be used as a replicable model to address the livelihood insecurity of the rural fisher folk. Most importantly it acts as a means for ensured alternative livelihood and to culture the indigenous fish stocks which are presently overexploited and are under the threat of extinction. This type of food production systems can decrease the fishing pressure on indigenous fish species and also generate alternative income for the inland rural fishers. “Microsate” cage fish culture endeavor for livelihood and nutritional security of the rural fisherfolks has become a promising intervention in India

Unraveling the effects of live microalgal enrichment on Artemia nauplii

Artemia nauplii, though deficient in many essential nutrients, are used extensively in fish/shellfish larviculture. Enrichment using various diets can enhance their nutrient profile to the required level. The present study examines the effects of enrichment of Artemia nauplii with live microalgae viz., Pavlova viridis, Isochrysis galbana, Nannochloropsis oculata and Dicrateria inornata. Total length and width, survival percentage and the fatty acid profile of the microalgae enriched and unenriched nuaplii were estimated at 0, 1, 3, 5, 7 and 9 h time intervals. No significant increase in total length and width was observed between the enriched and unenriched Artemia nauplii during the study, indicating the absence of any enrichment diet induced growth rate of the nauplii. Salinity stress study revealed that the microalgae enriched nauplii can live long in low saline conditions than the unenriched nauplii. The total PUFA content of the live microalgae enriched nauplii reached maximum at 7 h post-enrichment followed by a significant drop after 9 h. The results of the study indicated that live microalgae can be used as excellent enrichment dietary sources for Artemia nauplii, which in turn can provide many of the vital nutrients essential for fish larviculture

Effect of salinity stress on biochemical constituents and ArHsp22 gene expression in Artemia franciscana

The present study analysed the effect of salinity stress on survival, biochemical constituents such as soluble protein, amino acid, trehalose and fatty acid, as well as real time expression of the Artemia heat-shock protein 22 (ArHsp 22) gene in Artemia franciscana. Results of the study revealed that Artemia can withstand sudden salinity increase up to 200 ppt without any mortality up to 6 h. Significantly higher mortality percentage was recorded at 24 h of incubation at 200 ppt. Short-term exposure to hypersaline conditions significantly reduced the protein content in Artemia while the protein biosynthesis enhanced after 24 h of incubation at 150 ppt salinity. Long term exposure to 200 ppt salinity did not show any further increase in amino acid content as observed at 100 and 150 ppt conditions, indicating reduced rate of amino acid metabolism and stress. Salt stress induced the synthesis of total polyunsaturated fatty acids (PUFA) in Artemia especially the 22:6n-3 and 20:5n-3 after 24 h of incubation at 150 ppt . Exposure to higher salinity induced trehalose production which indicated its vital role in combating salt stress in Artemia. The present study also indicated that short-term salt stress can significantly enhance the ArHsp22 gene expression in Artemia adults

Report on Amyloodinium spp. cysts infection in clownfish

A study was undertaken to record the occurrence of parasitic infections in ocellaris clownfish, Amphiprion ocellaris. Of a total eight A. ocellaris maintained in hatchery, three were found infected with different developmental stages of Amyloodinium spp. and were kept under observation

പടന്നയിലെ കല്ലുമ്മക്കായ കൃഷിനാശം : കൃഷി വീണ്ടെടുക്കാൻ ചില നിർദേശങ്ങൾ 2016 - 17 ൽ CMFRI നടത്തിയ പഠനറിപ്പോർട്ടിന്റെ പ്രസക്തഭാഗങ്ങൾ

പടന്നയിലെ കല്ലുമ്മക്കായ കൃഷിനാശം : കൃഷി വീണ്ടെടുക്കാൻ ചില നിർദേശങ്ങൾ 2016 - 17 ൽ CMFRI നടത്തിയ പഠനറിപ്പോർട്ടിന്റെ പ്രസക്തഭാഗങ്ങ