Northwest Coast Of India Research Articles

Additional Report and Taxonomic Description of Common Pike Conger Muraenesox bagio (Hamilton, 1822) from Dholai Fishing Harbour, Gujarat, Northwest Coast of India

Muraenesox bagio was identified and described from Dholai fishing harbour on the Gujarat coast, northwest coast of India, marking the first recorded occurrence of this species in the region. Muraenesox bagio, a member of the family Muraenosocidae, shares significant morphological and genetic similarities with its closely related species, Muraenesox cinereus. This report confirms the presence of Muraenesox bagio along the northwest coast of India and provides a comprehensive account of its taxonomy and detailed morphological descriptions.

Distribution of an Isopod Parasite Mothocya renardi in the Host Strongylura leiura from Arabian Sea Gujarat Coast, India

Crustacean isopod parasites, particularly in the marine environment, are prevalent around warmer seas and can significantly impact local fish populations. Mothocya renardi, a notable species of isopod parasites, commonly infests fishes in shallow, turbid coastal waters. This study aimed to investigate the occurrence, taxonomy, and morphology of M. renardi infesting Strongylura leiura in the Arabian Sea around the northwest coast of India. Samples were collected from Dholai fishing harbor (Navsari District of Gujarat), during the post-monsoon months. Three specimens of S. leiura were found infected with pairs of male and female M. renardi in the brachial chambers, with all female parasites being brooded ovigerous. Detailed morphological analysis confirmed the presence of M. renardi, extending its known geographical range to the Arabian Sea.

Extended distribution of the Indian golden-barred butterflyfish, Roa jayakari (Acanthuriformes: Chaetodontidae), North-West coast of India

Extended distribution of the Indian golden-barred butterflyfish, Roa jayakari (Acanthuriformes: Chaetodontidae), North-West coast of India

New Distributional Record for Siganus vermiculatus (Valenciennes 1835) from the Veraval Fishing Landing Centre along Northwest Coast of India

New Distributional Record for Siganus vermiculatus (Valenciennes 1835) from the Veraval Fishing Landing Centre along Northwest Coast of India

First Geographic Record of Acanthurus xanthopterus and Family Acanthuridae from the Gulf of Kachchh, Northwest Coast of India

First Geographic Record of Acanthurus xanthopterus and Family Acanthuridae from the Gulf of Kachchh, Northwest Coast of India

Relationship between dietary fiber content and prebiotic potential of polysaccharides from the seaweeds of the North west coast of India

The macroalgae are a sustainable bioresource that can be harnessed for their functional food and nutraceutical applications. This study characterized the biochemical composition and bioactive potential of natural biological macromolecules, such as macroalgal polysaccharides extracted using a green, aqueous extraction process. The in-vitro antioxidant and antiglycemic activity of these polysaccharides were evaluated using model, free radical and antiglycemic compounds. The prebiotic potential of macroalgal polysaccharides were analysed based on their ability to promote the growth of two potential probiotic bacteria Lactobacillus acidophilus and L. bulgaricus and suppress the growth of enteric bacteria, Escherichia coli. Among the polysaccharides studied, the brown algal polysaccharide MPS8 MPS9 and MPS10 exhibited good antioxidant, antiglycemic and prebiotic activity. Based on infrared spectroscopy, the functional groups sulfation and carboxylation were identified in potential polysaccharides. The monosaccharide composition in the bioactive polysaccharides was determined using High Performance Anion Exchange Chromatography Pulse Amperometric detector (HPAEC-PAD). These bioactive polysaccharides were fractionated using ion exchange chromatography to purify it and further characterized using gel permeation chromatography and NMR spectroscopy. The results these polysaccharides are mainly composed of fucose and glucose which is due to the fucoidan and laminarin, respectively. Such macromolecules with high dietary fiber content and bioactivity are in global demand as functional food, nutraceutical and pharmaceutical formulations.

First record of the three-spined box crab, Arcania undecimspinosa De Haan, 1841 (Decapoda, Brachyura, Leucosiidae) from the Arabian Sea, with a key to the species of Arcania recorded from the Indian coast

Abstract A single specimen of the three-spined box crab, Arcania undecimspinosa De Haan, 1841, measuring 21.0 mm CW and 20.5 mm CL, is here documented for the first time from the Arabian Sea along the north-west coast of India. Previously, the species has been only reported from the Bay of Bengal region along the Indian coast. The present study provides a detailed taxonomic description of the species with high-resolution colour photographs and line drawings, along with a key to the species of the genus Arcania known from the Indian coast.

Analysis of bycatches from mid-water trawl fishery targeting ribbonfish Trichiurus lepturus on the north-west coast of India

Commercial trawl fisheries are closely associated with bycatch and discards and itsignificantly affects the non-target resources, biodiversity, ecosystem function and habitat.The present study analysed bycatch based on data obtained from commercially operatedmultiday midwater trawlers operating off the north-west coast of India during August2017-December 2019. The data revealed that bycatch and discards constituted about 53and 6% respectively of the trawl catch. Mid-water trawl bycatch comprised 92 Teleosts,8 Cephalopods, 12 Crustaceans and 11 Elasmobranch species. The bycatch is mainlycomprised of cuttlefishes, squids, threadfin breams, sciaenids, bullseye and lizardfishes.Further, 93.68% of the bycatch consisted of commercially important fish, hence it wasretained in the vessel. The bycatch rate was high in September (72.81±37.44 kg h-1) whereas,for discards, it was in August (16.25±10.84 kg h-1). Keywords:Arabian Sea. Bycatch, Discard, Midwater trawl,Ribbonfish

Deciphering the seasonal dynamics of microplastic morphotypes and associated co-contaminants along the northwest coast of India

In the present study, the northwest coast of India, bordering the Arabian Sea, was selected to evaluate the microplastic (MP) abundance. This is the first study to emphasize the effects of different seasons on MP distribution. The collected MPs were dried, segregated, and evaluated based on their morphotype, size, color, and polymer type. A total of 1756.6, 7326.6, and 202 particles/kg of sand were estimated in the pre-monsoon, monsoon and post-monsoon seasons, respectively, with a dominance of polypropylene (PP) type of plastic in the pre-monsoon and high-density polyethylene (HDPE) in monsoon and post-monsoon seasons. HDPE and PP collected MPs during the monsoon season were further characterized for associated contaminants. Metal absorbance was detected using SEM-EDX mapping and ICP-MS. The presence of organic compounds (OCs) was analyzed using GC-MS. MPs exhibit distinct associations with metals, among which the HDPE pellet morphotype exhibits a higher range of metal adsorption. Total 61 different OCs were associated with MPs. The HDPE pellets contained the highest amounts of hydrophobic organic compounds. PP pellets were found to contain triglycerides, fatty aldehydes, and alkaloids, along with HOCs. Among morphotypes, pellet forms of MPs were found to adsorb more contaminants. These co-contaminants infiltrate the study area through sewage runoff and shoreline debris deposition, subsequently interacting with MPs. Furthermore, the MP diversity was studied by employing the MP diversity integrated index, which suggests that most of the MP diversity was observed in the pre-monsoon period. The pollution load index employed an MP risk assessment, which presented a low degree of MP contamination. In contrast, the polymer hazard index was calculated as 21650.3 in post-monsoon, placing the area under the extreme danger category. It is evident from the data that the types of MP is more important than their number. Thus, MP morphotypes have importance in the adsorption of co-contaminants.

Microplastic(MP) occurrence in pelagic and demersal fishes of Gujarat, northwest coast of India.

Microplastics (MPs) are globally observed in marine as well as freshwater habitats, and laboratory studies have shown that marine organisms can accidentally ingest them. Monitoring the MP ingestion by fish in the environment is very crucial for understanding the risk of consuming MP-contaminated fish for human health. In this study, we investigated MP ingestion in 400 fish individuals from the Veraval Coast, in the state of Gujarat, India. There was 100% MP occurrence in the inedible tissues of fish, and 68% of the analyzed fishes presented MPs in edible tissues. The most dominant MPs based on their size in fishes were 0.05-0.1 mm. One hundred percent presence of only fibres in edible tissue was observed, while in inedible tissue, it was 77%, 20.42% and 2.58% of fibre, fragment and film respectively. The most common MP colour was blue. The predominant polymers were low-density polyethylene (LDPE) followed by polypropylene, high-density polyethylene (HDPE) and polystyrene. This is the first study performed on MPs in marine fishes from this region. Our findings suggest that the abundance of MPs observed in this area is higher than in other states of the country.

Distribution, source and potential biological impacts of polycyclic aromatic hydrocarbons in the core sediments of a networked aquatic system in the northwest coast of India – A special focus on Thane Creek Flamingo Sanctuary (Ramsar site)

Mumbai, one of the most industrialised and inhabited cities in the world, has been confronting an exponential increase in pollution brought about by anthropogenic activities throughout its coastal belt over the years. The historical accumulation of 16 polycyclic aromatic hydrocarbons (PAHs) in the sediments of Thane creek, Panvel creek and the Ulhas estuarine river system was examined in light of these circumstances. The present study has found that the PAHs were distributed vertically in the sediments of Thane Creek as 16.53 – 1317.02 ng/g dw and Ulhas Estuary as 105.44 – 1815.20 ng/g dw. Major sources of PAHs pollution to the system like petroleum spillages, biomass burning and vehicular exhaust was discernible based on molecular diagnostic ratio (MDR) and principal component analysis (PCA) tools, signifying petrogenic and pyrogenic origins. Based on the total toxicity equivalence (TEQ) and sediment quality guidelines (SQGs) indices, high or moderate contamination risks have been identified in the lower and middle regions of the Ulhas estuary, as well as in the lower regions of Thane creek. Specifically, high contamination risk of benzo[a]pyrene which has high cancerous potential, was identified in the above sites.

Diapycnal mixing induced by salt finger and internal tides on the northwest coast of India

Microstructure measurements of velocity shear from the continental slope of the northwest coast of India (NWCI) in the eastern Arabian Sea are used to quantify the relative importance of double diffusion and internal tides induced diapycnal mixing in the different depth layers. It is found that the hydrographic conditions in the NWCI are conducive to the formation of moderately strong salt fingering (Turner angle between 55° and 72°). However, salt finger-induced vertical mixing dominates only in the upper 180 m of the water column, below which intense shear-driven turbulent mixing due to internal tide reduces its significance. As a result of this, the staircase structures, a measure of salt finger dominance in the water column, are frequent, and the mean temperature change across the interface (DTIH; 0.33 °C) is relatively larger in the upper 180 m compared to sporadic occurrence of steps with a small magnitude of DTIH (0.18 °C) below 180 m. It is also found that in the upper 180 m of the water column in the NWCI, mean diapycnal diffusivity (Kρ) is approximately a factor of eight larger (8.3 ± 1.3 × 10−5 m2s−1) than the estimation in the open ocean region of the eastern Arabian sea (5.4 ± 1.1 × 10−6 m2 s−1). However, due to internal tides, the magnitude of Kρ reaches as large as O (10−2) m2 s−1 below 180 m in the NWCI. The mean downward heat flux estimated in the salt finger-dominated (upper 180 m) layers is ∼ -6.1 Wm-2, and the shear-driven mixing-dominated layers (below 180 m) is ∼ -10.2 Wm-2.

First record of goneplacid crab, Carcinoplax haswelli (Decapoda: Brachyura: Goneplacidae) from the Indian Ocean

Abstract A single male specimen of Goneplacid crab, Carcinoplax haswelli (Miers, 1884) is recorded for the first time from the Indian Ocean. The crab specimen was collected from the trawl bycatch landing of the commercial demersal trawler operated between 30 and 150 m depth along the Gujarat coastal region, Northwest coast of India. This C. haswelli is previously recorded from northern Australia and Taiwan to South China Sea. Until now, C. haswelli is not observed or recorded from the Indian Ocean. In the present study, detailed information regarding the taxonomic identification and previous distribution of the goneplacid crab, C. haswelli is described.

First record of two cylindrical crab species of the genus Ixa (Decapoda, Brachyura, Leucosiidae) from the eastern Arabian Sea, with a key to the species of Ixa recorded from the Indian coast

Abstract Two cylindrical crabs, Ixa cylindrus (Fabricius, 1777) and Ixa edwardsii Lucas, 1858 are herein recorded for the first time from the coastal waters of the eastern Arabian Sea. Both species were collected from the bycatch landing of the commercial demersal trawlers operated along the Gujarat coastal region, northwest coast of India, between 20 and 80 m depth. Both species have been recorded from the Bay of Bengal on the east coast of India, but there is no detailed information available on their taxonomic identification and global distributional records.

Diet composition and reproductive biology of spineless cuttlefish Sepiella inermis (Orbigny, 1848) from Ratnagiri (Arabian Sea, North-west coast of India)

In the present study, we investigated some biological aspects of the spineless cuttlefish,Sepiella inermis (Orbigny, 1848) along the Ratnagiri coast of Maharashtra, India. A study ondiet composition and reproductive biology of the species was carried out. Dorsal mantlelength (DML) ranged from 35.9 to 93.3 mm for males and 29.3 to 98 mm for females.Feeding intensity was noted to be low during most of the study period. S. inermis was foundto have a protracted spawning season. The overall male: female ratio was 1:1.02 during thestudy period. The average fecundity was found to be 358 eggs. Length at sexual maturitywas estimated to be 42 mm and 53 mm for males and females respectively. The informationobtained from the study will help the fishery agencies to formulate management measuresin sustaining the landings of S. inermis in the region. Keywords:Biological studies, Cephalopods, Maharashtra,Ratnagiri coast, Sepiella inermis, Spinelesscuttlefish

Towards Sustainable Bombay Duck Fishery Along the North-West Coast of India in Changing Environmental Regime

Towards Sustainable Bombay Duck Fishery Along the North-West Coast of India in Changing Environmental Regime

Range Extension of Wedgetail Filefish, Paramonacanthus frenatus (Peters, 1855) from North-West Coast of India with a New Record of Maximum Standard Length

Range Extension of Wedgetail Filefish, Paramonacanthus frenatus (Peters, 1855) from North-West Coast of India with a New Record of Maximum Standard Length

New Distributional Record of Red Frog Crab, Ranina ranina (Linnaeus, 1758) (Decapoda: Raninidae) with Finding of Maximum Carapace Length from North-West Coast of India

New Distributional Record of Red Frog Crab, Ranina ranina (Linnaeus, 1758) (Decapoda: Raninidae) with Finding of Maximum Carapace Length from North-West Coast of India

Ecobiology and distribution of Streptomyces species from distinctive metal polluted sediment of tropical estuary, Northwest coast of India

The present study aims to isolate diverse actinomycetes communities from the estuarine sediments of Patalganga located at Northwest coast of India. Total 40 actinomycetes were isolated from 24 sediment samples by dilution plating on six different isolation media. Among them, morphologically 18 distinct selected isolates of actinomycetes were verified by 16S rRNA gene sequencing and identified as Streptomyces spp. The relationship between diversity of total actinomycetes population (TAP) and its antagonistic behaviour with the physico-chemical characteristics of sediment samples were investigated. Multiple regression analysis revealed that the influencing physico-chemical factors comprises of sediment temperature, sediment pH, organic carbon and heavy metals. The results of statistical analysis showed that TAP is positively correlated (p < 0.01) with sediment organic carbon whereas, negatively correlated with Cr (p < 0.05) and Mn (p < 0.01). Based on Principle component Analysis (PCA) and cluster analysis results, the obtained six stations can be divided into three groups. Among them mobile fraction of metals, TAP could be the main factor reflecting the lower and middle estuary. The recovery of large number of actinomycete isolates suggests that Patalganga Estuary could be potential source of bioactive compounds with biosynthetic capabilities.

Exploring biophysical links of catch rate from mid-water trawl fishery in the north-west coast of India, Eastern Arabian Sea: A remote sensing approach

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 factors impacting the catch rate and the spatio-temporal distribution patterns of fish along northwest coast of India (NWCI) from 2017 to 2019. The time series images of sea surface temperature (SST), sea surface height anomaly (SSHa), chlorophyll-a concentration (CHL), and euphotic depth (Zeu) indicate close coupling between bio-physical variables in the region. Generalized Additive Model (GAM) applied to the catch rate of mid-water trawlers found that CHL and Zeu were the most influential variables for ribbonfish distribution, while CHL and SST influence squid distribution and SST and SSHa influence cuttlefish distribution. The total deviation explained 37.70 %, 10.70 %, and 22.28 % in the final model for simulating the spatio-temporal distribution of ribbonfish, squid, and cuttlefish, respectively. Environmental factors were significant in the final GAM model (p < 0.05). Spatio-temporal distribution patterns of fishery resources from mid-water trawlers showed that they were related to biophysical changes in the northwest coast of India. The high catch rate was observed in the northern latitudes during the post-monsoon (October), the major fishing season in the region. However, it shrank and shifted to southern latitudes during the winter (January). This study could be adapted to nearby countries in the Arabian Sea region for an effective and useful tool to monitor and manage the fishery resources. Furthermore, it could aid in decision-making for policymakers and resource managers to formulate strategies for holistic marine fishery management and sustainable resource exploitation.