During the present study, the sublethal effects of two organophosphorus pesticides, chlorpyrifos (CPF) and dimethoate (DMT), on the gut flora of Litopenaeus vannamei (Boone, 1931), Whiteleg shrimp juveniles were studied for 21 days. Bacterial species such as Alteromonas sp., Bacillus sp., Demequina sp., Micrococcus sp., Pseudomonas sp., Pseudoalteromonas sp., Pseudoruegeria sp., Staphylococcus sp., Shewanella sp., and Vibrio sp. were reported from the guts of shrimps exposed to pesticides and in control groups. Bacteria such as Demequina flava, D. globuliformis and Pseudoruegeria sp. were isolated for the first time from the gut flora of L. vannamei. During the 21 Days of Exposure (DoE), a total of 17 different bacterial strains were identified from the control group; however, 10 and 12 strains were identified from the CPF-and DMT-treated groups, respectively. The bacterial diversity quantified by the Shannon diversity index (H') in CPF-and DMT-exposed shrimps was observed to decrease over the exposure period compared to the control. Pesticide exposure leads to a decrease in valuable microbes and an increase in harmful microbes in the gut microflora of shrimp. Therefore, this may result in reduced growth, weakened health, increased susceptibility to diseases, and a decrease in the production of high-quality shrimp.
In the current investigation, an eco-friendly packaging film comprising fish skin-derived collagen (COL), Sodium Alginate (SA) functionalised with Orange Peel Extract (OPE), and silver nanoparticles (AgNPs) was fabricated. Notably, the synergistic action of nano-fillers and peel extracts in the film matrix significantly (p < 0.05) improves the mechanical and light barrier properties and antioxidant activity of the COL/SA bio-composite. Scanning Electron Microscopy (SEM) illustrated pronounced alterations in the microstructure of the COL/SA film. At the same time, Fourier Transform Infrared (FTIR) spectroscopy revealed intricate structural interactions within the matrix, predominantly through hydrogen bonding. Furthermore, the freshness of the fresh basa fillet attributes during 12 days of refrigerated storage was monitored, and the evaluation depicted that the film with combined treatments (COL/SA/OPE/AgNPs) retards lipid oxidation, inhibits bacterial growth, and enhances the sensory score, effectively. These findings underscore the promising potential of these films as innovative and effective packaging materials.
Offshore surface sediments were collected along the south Karnataka coast of India, from the Netravati River mouth to Manjeshwar, to investigate the spatial distribution of metals. Average concentration of the metals in the 90 km(2) area followed the order Cd < Pb < Co < Cu < Ni < Zn < Cr < Sr < Mn < Mg < Ti < Ca < Fe < Al. Trace metal contamination levels were assessed using various pollution indices, indicating that Mn, Ni, Cu, and Zn do not show significant contamination, whereas Cr exhibits moderate contamination in the study area. Areas around the mouth of the Netravati River and distant from the shore are considered polluted, as indicated by the Pollution Load Index (PLI), which is greater than 1. A close relationship between Cr and river-laden sediments indicates that the Netravati River is bringing Cr, an enriched element, to the study area.
Ocean Heat Content (OHC) is crucial for understanding ocean dynamics. The Northwest Indian Ocean (NWIO) region, comprising the Southern Red Sea, the Gulf of Aden, the Arabian Sea, and the Equatorial North West Indian Ocean, is affected by various phenomena, such as upwelling, heat waves, and multi-layer exchange between the Red Sea and the Gulf of Aden. The spatial and temporal variability of these factors affects upper-layer OHC. OHC in the NWIO region has rarely been studied earlier. Therefore, this work would be beneficial in filling the knowledge gap and understanding the OHC of this region. The study displays the horizontal distributions of monthly OHC and yearly signal amplitudes, calculated as the difference between maximum and minimum values across all months, along with the monthly mean OHC patterns in the upper 100 m and 300 m layers of the NWIO, based on the available historical seawater temperature and salinity data from the World Data Centre (WDC-A, Washington D.C.), WDC-B (Moscow) and the Egyptian National Oceanographic Data Centre (ENODC). The region exhibited a similar pattern of monthly average OHC in the upper 100 and 300 m layers, except within the Equatorial North West Indian Ocean zone. In addition, the lower layer within the Red Sea exhibited a different pattern during the winter and transitional months. The NWIO region demonstrated homogeneous annual OHC signal amplitudes, except for the Arabian Sea, which has the highest annual amplitude at both layers.
The present study reports three ornamental butterflyfishes, namely, Chaetodon lineolatus Cuvier, 1831; Heniochus singularis Smith & Radcliffe, 1911; and Roa jayakari (Norman, 1939), for the first time from the West Bengal coast, India. The presence of these species in non-reef areas suggests the need for research into their habitat preferences in West Bengal's exclusive economic zone.
The study reports two species of parasitic trematodes in fishes, namely, Coitocaecum plagiorchis Ozaki, 1926 (Opecoelidae) and Prosorhynchus squamatus Odhner, 1905 (Bucephalidae). These parasites were collected from the fishes Glossogobius giuris (Hamilton, 1822) and Synaptura commersonnii (Lacep & egrave;de, 1802), respectively, from the riverside of Lothian Island in the Sundarban Biosphere Reserve, West Bengal (India). Both reported species constitute new records for the Indian fauna, while both fish species constitute new host records for the respective parasites. The description and distribution of these parasites are discussed in the present study.
Finfish and shellfish diversity at three sampling sites of the Sitakunda coast of the Bay of Bengal were studied monthly from March 2016 to February 2018, wherein 355181 fishery individuals were enumerated from 554 catch samples collected by 13 different types of gears. Out of a total of 168 fish species identified, 124 were finfish species (13 orders and 47 families), and 44 were shellfish species (2 orders and 8 families). The order Decapoda (65.17 %) occupied the highest position, followed by Perciformes (20.59 %), Scopeliformes (5.37 %), Clupeiformes (4.97 %), Siluriformes (1.35 %), Pleuronectiformes (1.18 %) and the remaining 9 orders contributed only 1.36 % of the total sampled population. Oxyurichthys keiensis is reported as a new record for Bangladesh. The highest numbers of individuals during pre-monsoon were recorded at Station II, and the lowest numbers of individuals from Station III during the post-monsoon season. Diversity indices showed no significant difference across years, but a significant differences were observed among stations. Stations I and II showed comparatively higher species abundance and diversity. According to the evenness index, the population of Station II was the most stable among the three stations. Analysis of Similarity (ANOSIM), Similarity Percentage Analysis (SIMPER), cluster analysis, and non-metric multidimensional scaling revealed clear differences in species populations across seasons.
Coastal and estuarine ecosystems face increasing threats from heavy metal pollution originating from industrial and agricultural activities, presenting significant environmental and public health risks. This study investigates arsenic and heavy metal contamination within surface sediments of eight major rivers discharging into the southern Caspian Sea: Gorganrud, Qarasu, Tajan, Babolrud, Sardabrud, Safarud, Cheshmeh Kileh, and Sefidrud. Twenty-four surface sediment samples, collected from upstream, river mouth, and near-shore zones, were analysed to assess spatial variations. A sediment core from Gorgan Bay, providing a similar to 1400-year depositional record, was also examined to understand historical trends. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine trace metal concentrations, along with grain size distribution and organic matter content analyses. Arsenic concentrations varied spatially, ranging from 0.3 to 18.45 mg/kg. Pollution indices, including modified contamination degree (mCd) and Pollution Load Index (PLI), revealed slight-to-moderate pollution in several rivers, while the Ecological Risk Index (RI) indicated consistently low ecological risk. Enrichment Factor (EF) analysis identified both natural and anthropogenic influences contributing to heavy metal accumulation. These results underscore the complex interplay of factors driving heavy metal contamination in the Caspian Sea estuaries, emphasising the need for long-term monitoring programs to support effective coastal management and mitigation efforts within this ecologically vital region.
The present study estimated the Length-Weight Relationships (LWRs) of Boleophthalmus dussumieri, Ilisha megaloptera, Aulopareia ocellata, Tenualosa ilisha, and Thryssa stenosoma. The fish samples were collected from the estuarine stretch (72 km) of the river Narmada from November 2018 to December 2020 seasonally, using bag nets (10 mm cod-end mesh size), stake nets (5-10 mm mesh size), and stick traps (locally known as fanda). The value of exponent b for LWRs ranged from 2.641 to 3.546. This study presents the first reference on LWR for T. stenosoma and the first LWRs for three other species (viz., B. dussumieri, I. megaloptera, and A. ocellata) in the Narmada estuary. Additionally, the study established a new maximum length record for T. stenosoma. The LWRs, along with other biological parameters of the respective species, serve as baseline information for the management and conservation of both migratory and local fishes.
This study evaluated trace and heavy metal concentrations (Ca, K, Cr, Mn, Co, Ni, Zn, Se, Ag, Ba) in nine commercially important fish species (Epinephelus marginalis, Mugil cephalus, Pagrus pagrus, Sole sole, Siganus canaliculatus, Lethrinus nebulosus, Sparus aurata, Mullus surmuletus, and Trachurus indicus) from the Red Sea, Saudi Arabia, using inductively coupled plasma mass spectrometry (ICP-MS). The highest metal concentrations were observed in Mugil cephalus (Cr: 0.157 mg/kg; Zn: 0.672 mg/kg), while Trachurus indicus exhibited the lowest levels (Cr: 0.002 mg/kg). All metal concentrations were below the permissible limits (FAO/WHO), with Cr and Ni representing only 7.4 % and 13.8 % of their respective thresholds. Health risk assessments (THQ < 1, HI < 1, CR < 10-6) indicated minimal risks for adults and children, with Estimated Weekly Intakes (EWI) for Cr (0.42 mu g/kg bw/week) and Ni (0.078 mu g/kg bw/week) below Provisional Tolerable Limits (PTWI). Principal Component Analysis (PCA) revealed that 86.8 % of metal variance was derived from natural sources (agricultural runoff, geological weathering), underscoring Yanbu's relatively pristine conditions compared to industrialised Red Sea regions. These findings highlight the need for ongoing monitoring to safeguard marine ecosystems and public health, particularly for benthic species such as M. cephalus, which showed a higher bioaccumulation potential.
The Ovalbone cuttlefish, Acanthosepion ellipticum (Hoyle, 1885), was recorded for the first time from the Ratnagiri waters, Maharashtra. This study provides significant baseline data on the distribution and occurrence of the species along the central west coast of India. The findings highlight the importance of systematic monitoring and further studies on cephalopod diversity in the regional context to fill existing knowledge gaps.
Maturation can also be assessed based on biochemical changes in the gonads of sea urchins. The biochemical composition (proteins, carbohydrates, and lipids) of gonads of Echinometra mathaei was assessed during the ovarian reproductive stages between April 2011 and November 2012. Protein constituted the major storage part of gonads in both sexes in all months (males: 47.0 +/- 22.2 mg g(-1), females: 73.8 +/- 25.8 mg g(-1)) followed by lipids (males: 43.4 +/- 12.8 mg g(-1), females: 62.1 +/- 14.5 mg g(-1)), and carbohydrates (males: 32.2 +/- 20.2 mg g(-1), females: 46.9 +/- 23.8 mg g(-1)). The results revealed that the protein, carbohydrate, and lipid contents of gonads exhibited significant shifts from highest to lowest concentrations. This indicates that the proximate composition of the gonads of E. mathaei is intrinsically linked to the species' annual reproductive cycle, representing a critical consideration for assessing its potential for nutritional and commercial utilisation. The greatest quality in biochemical content was observed from February to May on the coast of Pakistan, when individuals with Stage I and II possess significantly higher concentrations of proteins and lipids, upheld by the nutritive phagocytes. Although, in Pakistan, there is no custom to eat sea urchin roe, and no sea urchin fishery exists; however, in the future, when this species becomes exploitable, such studies will be very important.
The sex ratio, biometric analysis, and life-history traits of 606 individuals (10.5 - 22.5 cm TL) of Upeneus moluccensis (Bleeker, 1855) were studied from September 2022 to August 2023 along Veraval fishing harbour, Gujarat, particularly in a geographic region where such information was previously scarce. The mean sex ratio (1F:1.03M) was found to be insignificant (p > 0.05; chi(2) test). Morphometric characteristics indicated significant (p < 0.05, univariate ANOVA) disparity between male and female specimens. Morphometric analyses and indices suggested a low coefficient of variation (< 16 %) and a restricted distribution of the species. Standard length and fork length showed a high growth rate and maximum correlation among different morphometric features for both sexes. The b value of length-weight relationships revealed hyperallometric growth (b > 3; p < 0.05, t-test), indicating that the fish become heavier as they grow. The near unity relative condition factor (K-n approximate to 1) and higher Fulton condition factor (K-F > 1.20) for both males and females suggested favourable growth conditions. Body condition, reflected by a higher percentage of lean fish, suggested October to December as the peak spawning period. Size-based estimates recommend a harvest size limit range of 13.3 - 16.3 cm for the species. The detailed biometric and life-history information provided in this study can facilitate conservation, management, and sustainable utilisation of this species in the study area.
Machine gun coral shrimp, Coralliocaris graminea, is reported for the first time from Lakshadweep, India, based on two specimens collected during low tide at a depth of 2 feet from Agatti Island. Globally, C. graminea was reported from the Eastern and Southern Indian Ocean, Gulf of Aden, Pacific Ocean and the Persian Gulf. However, the occurrence of C. graminea has not been reported from the Arabian Sea. In this context, the present study provides a new distributional record of C. graminea from the Lakshadweep Islands, India. Detailed information about the taxonomic identification of the species, taxonomic remarks, and previous distribution is discussed.
Observations of short-finned pilot whales ( (Globicephala macrorhynchus) in the wild are relatively infrequent. This study reports an opportunistic live sighting recorded on 12 February 2024 in the Lakshadweep Islands of the southeastern Arabian Sea, based on vessel-based visual observations conducted aboard FORV Sagar Sampada. The sightings occurred (10 degrees 43 ' 74" N; 73 degrees 27 ' 35" E), a small pod of six individuals, each approximately 3 m in length at 1800 m depth. Environmental conditions at the sighting location were evaluated using both on-field and satellite-sourced datasets. Sea surface temperatures (SST) ranged between 29 and 31.5 degrees C, while salinity values indicated moderately stable oceanic conditions. Chlorophyll concentrations were relatively low, signifying oligotrophic surface waters during the observation period. These environmental characteristics may influence prey availability and influence the habitat use by short-finned pilot whales in the southeastern Arabian Sea.
The current study used GIS mapping to identify potential fishing areas for Chrysochir aurea (Richardson, 1846), a commercially important sciaenid species, along the coast of West Bengal, India, by analysing its spatio-temporal distribution and abundance. Data were collected from two purposively selected trawlers operating along the coast of West Bengal from October 2021 to September 2022. Chrysochir aurea was found to be distributed at depths ranging from 10 m to 67 m, with the largest catch per hour value (19.07 kg h-1) occurring at depths ranging between 10 m and 30 m. The maximum catch was recorded in the southeast, which is regarded as a potential fishing zone along the coast. The predictive maps inferred that the species is more prevalent in the southeast region during pre-monsoon and both southeast and southwest regions during post-monsoon and winter seasons. Spatio-temporal distribution of C. aurea, recorded in the present study, will not only help in identifying the potential fishing grounds but also in framing management strategies for sustainable fisheries along the West Bengal coast.
The present study aimed to generate baseline biometric data of rainbow sardine Dussumieria acuta from the Andaman Islands. A total of 127 specimens were analysed to examine meristic and morphometric characters, while 939 specimens were used to assess sex ratio, length-weight relationship, and relative condition factor. Eight meristic and twenty-eight morphometric characters were recorded for the current study. Based on the current study of meristic characters, the fin formula for D. acuta can be represented as follows: B14-15D18-19P14V8A14-15C19G(10-11)+(21-22). The coefficient of correlation (r) ranged from 0.536 to 0.983 for total length against different morphometric characters and from 0.724 to 0.785 for head length against different morphometric characters. After applying a log transformation, the pairwise linear regression between total length and various morphometric variables indicated that most characters' 'b' value was close to unity. The male-to-female ratio in the above species showed no significance difference from the theoretical 1:1 ratio. The lengthweight relationship for D. acuta was expressed as W = 0.0053L3.1822 for pooled samples, W = 0.0049L3.2109 for males, and W = 0.0063L3.116 for females. The relative condition factor (Kn) was close to an ideal threshold value in both males and females and across all seasons.
This paper reports the rediscovery of a rare deep-water pylochelid hermit crab, Xylocheles miersi (Alcock and Anderson, 1899), from the Indian Exclusive Economic Zone based on a specimen collected off Narcondam Island, the Andaman Sea, using a High-Speed Demersal Trawl at a depth of 300 m. This is the second record of this species from the type locality. Detailed photographs of the morphological characters of the present specimen and its DNA barcodes of the partial mitochondrial COI and 16S rRNA genes are provided herein.
The Whipfin silverbiddy, Gerres filamentosus Cuvier, 1829 is exploited by beach seines, bottom trawls, long lines, stake nets and gillnets at Ratnagiri in Maharashtra. Morphometric characters, Length-Weight Relationship (LWR) and condition factor of the G. filamentosus were studied from 506 specimens comprising 242 males, 229 females and 35 indeterminants. The coefficient of correlation of total length against other morphometric characters of G. filamentosus ranged between 0.807 (vs. snout length) to 0.994 (vs. standard length). All morphometric measures had a high and moderate degree of correlation with total length. The LWR indicated positive allometric growth. The coefficient of correlation (r) for the LWR was estimated at 0.9824, 0.9760, 0.9839 and 0.9826 for the males, females, indeterminants and pooled data, respectively. Furthermore, the condition factor indicated that the species remained in good condition throughout the year for both sexes, except during August.
Four rare marine fish species of flying gurnards of the family Dactylopteridae are hereby reported for the first time from the West Bengal coast, India. The species viz. Dactyloptena macracantha (Bleeker, 1855), D. orientalis (Cuvier, 1829), D. peterseni (Nystrom, 1887) and D. papilio Ogilby, 1910 were collected from Petuaghat fishing harbour, Purba Medinipur district. This paper reports these four species as new distributional records from the coastal waters of West Bengal, along with their diagnostic characteristics and morphometric data. The study also confirms the report of D. papilio, from Indian waters. Comments on the records of Dactyloptena species from Indian waters are also presented.
