Dr A Gopalakrishnan

Central Marine Fisheries Research Institute | CMFRI · Director

The Indian scad, Decapterus russelli is one of the most exploited pelagic resources of India. Population genetic analyses using mitochondrial and nuclear markers indicated a lack of genetic structuring among populations from Indian waters. As this species is highly migratory, it is also important to establish the environmental influence on its popu...

The occurrence of five species of sunfish along the Indian coastline is reviewed for the period 1953-2022 based on published records for the period 1953-2021 and discussions with fishermen during the period 2017-2022. Four species of sunfish with 40 records have been documented belonging to three genera. Of the eighteen fishes of Masturus lanceolat...

Background Interleukin 10 (IL-10) is uniquely positioned in the immune regulation of teleosts. Modifying the IL-10 pathway changes the teleost’s disease susceptibility; however, there is no data on its post-transcriptional regulation. Trachinotus blochii is a high-value mariculture species. Methods The full-length tbil-10 gene was generated throug...

Mariculture, a sustainable and rapidly growing aquaculture sub-sector, meets global seafood demand while reducing strain on wild fish stocks and continues to expand worldwide. However, rising feed and seed costs pose significant challenges, overshadowing other farming expenses. Climate change exacerbates the profitability of sea cage farming, incre...

Cephalopods have dominated the oceans for hundreds of millions of years and are unquestionably at the peak of molluscan evolution. The development of the large brain and a well-sophisticated sensory system contributed significantly to its success. Therefore, it is considered the best example of convergent evolution and attracted the attention of sc...

Trachinotus blochii is a high-value tropical mariculture species. The present study evaluated the gut microbial impact of therapeutic exposure (80 mg/day/kg biomass for 10 days) to oxytetracycline, the most common aquaculture antibiotic in T. blochii. The cultivable counts, α-diversity measures of taxonomic and functional metagenomics, microbial dy...

We characterized the complete mitogenome of Nemip-terus randalli and performed comparative mitogenomic analysis with previously determined mitochondrial geno-mes belonging to the family Nemipteridae. Using Sanger sequencing, we identified a 16,642 bp mitogenome containing 37 genes (13 protein-coding, 2 rRNA, 22 tRNA) and a non-coding region. Its ge...

There is a need to increase focus on the oceans for producing more food and generating technologies in the non-food sector. India’s Blue Economy is the centrepiece where different disciplines are converging to generate food and wealth. The phenomenal potential of the non-food sector of marine biotechnology unfolds through the promise of new drugs a...

Polyunsaturated fatty acids (PUFA) are vital molecules in the pharmaceutical, medical, and nutritional industries. Exploration of bacterial strains capable of producing significant amounts of PUFAs offers a promising avenue for biotechnological applications and industrial-scale production. However, an extensive screening of several samples from div...

The Asian green mussel, Perna viridis is an important aquaculture species in the family Mytilidae contributing substantially to molluscan aquaculture. We generated a high-quality chromosome level assembly of this species by combining PacBio single molecule sequencing technique (SMRT), Illumina paired-end sequencing, high-throughput chromosome confo...

Temperature is one of the crucial environmental factors affecting the physiology and suitability of fish species for aquaculture, making it vital to predict how the present rate of climate change will impact these species. To assess the heat tolerance of silver pompano Trachinotus blochii, the Critical Thermal Maxima (CT max) and Critical Thermal M...

This study provides the first documentation of three deep conspecific lineages within Panulirus polyphagus in the Indian Ocean, bridging the gap in genetic research. Comparative mitogenomics between lineages (L) at both species and family levels, evolutionary relationships and heterogeneity of sequence divergence within Decapoda, and divergence tim...

In this study, a new brain cell line designated PB1BrTr was derived from the maroon clownfish Premnas biaculeatus (Bloch, 1790) and characterised. The PB1BrTr cell line was developed by trypsinisation method using Leibovitz’s L15 (L-15) medium supplemented with 20% FBS (foetal bovine serum) and subcultured over 100 times. Characterisation encompass...

Commercial-scale seaweed production in exposed coastal waters has failed due to the absence of appropriate culture methods. In the present study a novel tube-net based seaweed cultivation in floating high-density polyethylene (HDPE) raft structure was developed for exposed and deeper coastal waters. The design prototype was evaluated by culturing K...

Successful captive seed production of the recently identified sparid, Sparidentex jamalensis, is a significant achievement for its farming and conservation. In each breeding attempt, a male with oozing milt was paired with a female freshly implanted with an LHRH-a pellet (100 μg LHRH Kg− 1 of fish). Oocyte diameter of the selected female was rangin...

The Japanese velvet dogfish Scymnodon ichiharai Yano and Tanaka 1984 (Somniosidae) is a rare deep-sea shark hitherto known only from the northwest Pacific Ocean. This species is observed for the first time from the northern Indian Ocean. Two male specimens with total length (TL) of 760 mm, and 323 mm were caught by longline hook in the commercial m...

The objective of this study is to provide information on the reproductive biology of tomato hind grouper, Cephalopholis sonnerati (Valenciennes, 1828) for conservation and management purposes. Fish caught by artisanal fishermen from September 2019 to August 2021 were analysed. A total of 280 females, 31 males, and 4 transitional and 178 sex‐undeter...

Introduction Deep investigations of host-associated microbiota can illuminate microbe-based solutions to improve production in an unprecedented manner. The poor larval survival represents the critical bottleneck in sustainable marine aquaculture practices. However, little is known about the microbiota profiles and their governing eco-evolutionary p...

India is one of the major fishing nations in the Indian Ocean, with commercial marine fishlandings in the country comprising of nearly 1000 species. A comprehensive and periodicassessment of the stocks is crucial for achieving the goals of sustainable fisheries harvestand management. The ICAR-Central Marine Fisheries Research Institute, Ministry of...

Artisanal fishers fishing in nearshore coastal waters off Visakhapatnam using motorisedcrafts and in estuaries of Krishna using non-motorised crafts were selected for the study.Their annual net operating income varied between US$ 469.63 (₹39,040) and US$ 2698.42(₹2,24,320), respectively. Inspired by the potential of cage farming from the frontlined...

This paper explores the possible options for quantitative fishery stock assessment in tropicalwaters and is composed of four layers viz., concepts, methodologies, data and indicators.The concept promotes the fundamental theory that has been popular in research on stockdynamics, including the possibility of combining it with various doses of intrins...

Nemipterus randalli, commonly known as Randall’s threadfin bream, is a commercially important marine finfish. Understanding its genetic structure is critical to effective management and conservation efforts. Previous investigations on population structure in this species were limited by geographic coverage. In this study, we utilized the mitochondr...

Aims To identify a marine L-asparaginase with clinically desirable attributes and characterize the shortlisted candidate through in silico tools Methods and results Marine bacterial strains (number=105) isolated from marine crabs were evaluated through a stepwise strategy incorporating the crucial attributes for therapeutic safety. The results dem...

Sharks have thrived in the oceans for 400 million years, experienced five extinctions and evolved into today’s apex predators. However, enormous genome size, poor karyotyping and limited tissue sampling options are the bottlenecks in shark research. Sharks of the family Orectolobiformes act as model species in transcriptome research with exceptiona...

Morphological changes during metamorphosis from larvae to juvenile stage vary considerably among teleosts. Metamorphosis in Acanthopagrus berda, a commercially important sparid, recorded using simple microscopy in captivity, revealed progressive changes in pigmentation, band formation, development of fins, and other morphological features. Larvae o...

The present study addresses the crucial sustainability concerns in small-scale fisheries (SSF) against the backdrop of escalating anthropogenic activities and climate change impacts on marine fishery and ecosystems. Our study focused on a traditional fishery exploitation area spanning 12,646.12 km2 along the Southwestern Coast of Kerala, India, and...

Silver pompano, Trachinotus blochii, is a high-value mariculture species for which captive seed production technology was standardised by ICAR-CMFRI in 2011. A comparative study of the growth and development of silver pompano during indoor and semi-outdoor larval rearing was conducted in duplicate batches. Fertilised eggs (10,000 no.) of silver pom...

Mariculture, a relatively low-carbon aquaculture sub-sector than other protein producing livestock systems is an important food-producing industry, continues to significantly expand its production at the global scale. Nevertheless , the sector's growth is vulnerable to climate change, typically driven by the temperature in the existing environment....

Lobsters are one of the premium ocean resources and a highly sought-after seafood commodity globally. The increasing demand for spiny lobsters in both domestic and international markets has led to a growing interest in mariculture as a means of meeting demand. Capture-based mariculture (CBM) by the coastal communities is the only way to cater the e...

The blue economy, encompassing sustainable utilization of coastal and oceanic resources, has gained global significance in the context of the developing discourse on economic growth and environmental conservation in ocean-based economies. This article delves into the multifaceted realm of India's fisheries and coastal aquaculture sectors, exploring...

Research on antioxidant biomarkers can generate profound insights into the defense mechanisms of fish larvae against different stressors and can reveal manipulation strategies for improved growth and survival. However, the number of samples to process and unavailability of required infrastructure in larval-rearing facilities limit the immediate pro...

Sea cage farming in marine open waters is considered as the most viable technique in Indianmariculture to enhance production. Owing to the support of the government in researchand development, and policy initiatives, marine cage farming is progressing steadily in thecountry. Technological guidance from research institutions and financing under the...

The Indian Scad, Decapterus russelli is an important pelagic carangid widely distributed throughout the Indian Ocean and the Indo-West Pacific. Despite being widely distributed in the Indian Ocean, the information regarding genetic structuring and diversity has been lacking compared to its Indo Malay Archipelago counterparts. The present study was...

Microbial dynamics across multiple ontogenetic stages represent one confounding feature in teleost microbiome research. The present study recorded the dynamics in the whole microbiome of early life stages and the juvenile gut microbiome of a high-value mariculture species, cobia (Rachycentron canadum), during standard culturing practices. This is t...

Scomberomorus guttatus has been subjected to a series of synonym assignations over the years. Its taxonomy has been mired with ambiguities due to the greater‐than‐average morphological variations observed in samples from different regions. An integrated taxonomic revision with molecular support indicated that the species that was thought to be a si...

Cage-based mariculture ventures in India are expanding, particularly emerging with the most sought-after candidate Asian seabass Lates calcarifer in territorial waters. However, comprehensive techno-economics have not been attempted, and thus hindering the sector's growth potential. To address this, a spatiotemporally validated decision-support mod...

The dietary composition, foraging strategies, and interspecific trophic interactions were identified for four major demersal carnivorous finfishes, namely, croaker Otolithes ruber, hairtail Trichiurus lepturus, threadfin bream Nemipterus japonicus, and lizardfish Saurida undosquamis, along the north‐western part of Bay of Bengal from 2014 to 2016....

The effect of stunting by feed and space deprivation on compensatory growth (CG) in Silver pompano, Trachinotus blochii, was investigated. A commercial pellet feed (45% protein and 10% fat) was fed two times a day, throughout the entire experiment. The 270-day experiment consisted of an initial 60-day stunting phase and a 60-day post-stunting phase...

The Indian oil sardine, Sardinella longiceps , is a widely distributed and commercially important small pelagic fish of the Northern Indian Ocean. The genome of the Indian oil sardine has been characterized using Illumina and Nanopore platforms. The assembly is 1.077 Gb (31.86 Mb Scaffold N50) in size with a repeat content of 23.24%. The BUSCO (Ben...

Good Management Practices in Seaweed Farming - a publication by ICAR-CMFRI.

Breeding and seed production of model fish Oryzias dancena in captivity by ICAR-CMFRI.

Evaluate the status of the bycatch with a sample study

Fish frequently shift their distribution ranges as a result of changes in preferred environmental factors. Knowledge on distribution of fish in relation to their environmental optima is crucial for improving the understanding of fishing grounds and planning sustainable exploitation. This study investigated the monthly variability in environmental f...

This study undertakes a comprehensive assessment of selected mariculture enterprises in the coastal regions of India, centered on long-term sustainability as the key focus. This is juxtaposed against India's ambitious blue economy targets and policy thrust that pin on the expansion of mariculture as a promising avenue for enhancing marine fish prod...

In the face of depleting wild stocks of lobster globally, mariculture is widely viewed as a technology for enhancing production, resource efficiency, economics, and effective management of dwindling stocks while supporting livelihood security. We used a novel multi-stage experimental strategy followed by robust non-linear growth model simulations f...

Cobia (Rachycentron canadum, Rachycentridae) is one of the prospective species for mariculture. The transcriptome-based study on cobia was hampered by an inadequate reference genome and a lack of full-length cDNAs. We used a long-read based sequencing technology (PacBio Sequel II Iso-Seq3 SMRT) to obtain complete transcriptome sequences from larvae...

Historically India has been projected as one of the major elasmobranch fishing nations in the world. However, management and conservation efforts are not commensurate with this trend. Along with the Wildlife (Protection) Act, 1972, several generic conservation measures are in place at the regional/local level. But India is still a long way from mee...

The article is about the hatchery technology of Perna viridis (Indian Peacock mussel)developed by the Vizhinjam Regional Centre of ICAR-CMFRI. It describes the microalgal culture, breeding, larval stages, larval rearing and nursery rearing of green mussels for large-scale seed production

In the Gulf of Mannar, Noctiluca scintillans blooms have been observed three times in September 2019, September and October 2020, and October 2021. It was determined and measured how the bloom period affects ichthyo-diversity. Noctiluca cell density varied slightly from year to year, ranging from1.8433 × 103 cells/L to 1.3824 x 106cells/L. In surfa...

Globally, many of the Elasmobranch species are threatened with extinction due to their vulnerable life history traits, habitat alterations, overexploitation, and climate change. The Spadenose shark, Scoliodon laticaudus Müller & Henle, 1838, is an amphidromous coastal shark that exhibits placental viviparity. The latest IUCN Red List of Threatened...

Serratia marcescens is a big emerging concern for human health and coral biodiversity. Spatial ecology and the infuencing factors on pathogen ecology, however, remain unknown. The study forms the frst global risk assessment of S. marcescens. MaxEnt niche modeling was applied using two biotic and sixteen abiotic variables. The world was classifed...

his document was prepared by a designated Indian CITES Scientific Authority, the ICAR-Central Marine Fisheries Research Institute (CMFRI), and is the result of an online workshop of the Demersal Fisheries Division of the Institute that took place during 5-7 August 2021

This document was prepared by a designated Indian CITES Scientific Authority, the ICAR-Central Marine Fisheries Research Institute (CMFRI), and is the result of an online workshop of the Demersal Fisheries Division of the Institute that took place during 2-4 September 2021

This document was prepared by a designated Indian CITES Scientific Authority, the Central Marine Fisheries Research Institute (ICAR-CMFRI), and is the result of an online workshop and ensuing discussions of the Demersal Fisheries Division of the Institute that took place during 5-7 August 2021.

The paper describes the first report of Kandelia candel (Rhizophoraceae), a rare mangrove from Bhavanapadu, a coastal village in Srikakulam district in Andhra Pradesh, India. This species is relatively less abundant along the east coast of India. During our study covering all the 41 mangrove patches in the state of Andhra Pradesh, 16 mangrove speci...

The marine ornamental fish trading industry is an ever-expanding one, as indicated by its bolstering statistics, which amount to about US$ 300 million. Although the trade is booming, the natural habitats that foster these fishes, such as coral reefs, are steadily declining. One of the reasons for this is the overdependency of the industry on wild-c...

Rich diversity of seaweeds represents an untapped reservoir of bioactive compounds with valuable pharmaceutical and biomedical use. Seaweeds were consumed by the coastal communities since prehistoric times, particularly in Japan and China, and also used up traditionally in Indonesia, the Philippines, South Korea, North Korea, Malaysia, and lately i...