- Histological Authentication of Reproductive Structures of Little Indian Squid Loliolus (Loliolus) hardwickei, Grey, 1849 (Cephalopoda: loliginidae)
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Occurrence of deep-water spider crab Paramaya mulli Ng, Prema & Ravichandran, 2018 from the Southwest coast of India
This study documents the occurrence of deep-water spider crab, Paramaya mulli, along the Southwest coast of India. Initially described in 2018 from Tamil Nadu on the east coast, this species was subsequently noted in 2020 in Gujarat on the west coast. The specimen was retrieved from by-catch discarded by commercial fishing trawlers at Sakthikulangara fishing harbour off Kollam, Kerala. Identification as Paramaya mulli was established through a combination of morphological and molecular data. Both 16S ribosomal RNA (16S rRNA) and cytochrome c oxidase I (COI) sequences from the current specimen were compared with the NCBI sequences of previously identified specimens. Phylogenetic analysis, using mitochondrial gene sequences (16S: OQ456467, OQ456468) from the present specimen and sequences obtained from NCBI GenBank, was conducted to elucidate the relationships of genus Paramaya.
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First record of the rare deep-sea shark, Scymnodon ichiharai Yano and Tanaka, 1984 (Squaliformes: Somniosidae) from Andaman Waters, India
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 motorized longline boat fishery at a depth of 400 m off Port Blair, Andaman Islands, India. We provide morphological descriptions of S. ichiharai from India in comparison with formerly identified specimens along with DNA barcodes from this region. The capture of this species in the northern Indian Ocean is a considerable biogeographic range extension and confirms the first record of S. ichiharai from the Indian EEZ.
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Stock Assessment of Exploited Populations of Shovel-Nosed Lobster Thenus unimaculatus (Scyllaridae, Burton and Davie, 2007) Along the Indian Coast Using Length-Based Approaches
This manuscript presents a detailed investigation into the stock status of Thenus unimaculatus, a commercially valuable lobster species in India. In data-poor fisheries, Bayesian approach offers robust guidance for sustainable sand lobster population management. Utilizing a non-conventional Bayesian approach, the study employed length-based Bayesian biomass (LBB) and length-based Spawning Potential Ratio (LB-SPR) methods to analyze length frequency data collected between 2011 and 2019. In our study using LBB, the current exploited biomass (B/B0 = 0.35) was found to be lower than the biomass capable of producing maximum sustainable yield (B/BMSY=0.93). Spawning potential ratio was calculated between 28 and 37% using LB-SPR model. The fishing mortality (F/M = 1.5) was slightly above optimal, resulting in low sand lobster biomass due to moderate over-exploitation. This suggests a need for rational slipper lobster catch control. However, with an Lm50/Lc50 ratio close to 1.0, indicates an absence of targeted juvenile fishery, it suggest the need to reduce fishing pressure. . However, implementing measures is challenging because the species forms a by-catch in trawl fisheries.
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Integrating marine citizen science with traditional research: a case study on Solenocera choprai distribution and growth in the Southeastern Arabian Sea
The use of ‘Citizen Science’ in marine fisheries research has facilitated public participation in natural resource management, resource conservation, environmental preservation, and decision-making worldwide. The potential of a ‘Marine Citizen Science’ platform, incorporating expertise and data provided by innovative, well-trained commercial fisherman organizations, rekindles a feasible opportunity for academics to monitor the fishery with low financial investment. The current study demonstrates the value of combining geo-tagged ‘Citizen Science data’ on the Solenocera choprai fishery with traditional landing data to illustrate its significant potential for obtaining extensive spatial information on the resource. Growth data derived from the traditional von Bertalanffy growth function (VBGF) were compared with in situ mode shifting in the natural fishing ground, using this data for support. The current study concludes that a well-organized scientific research program that incorporates ‘Citizen Science’ data analysis can pave the way for extensive research in marine fishery resources and fishing grounds that have been put on hold due to a lack of financing.
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Investigation on the distribution dynamics of kiddi prawn, Parapenaeopsis stylifera (H. Milne Edwards, 1837) along southwest coast of India, using multi-dimensional approach
Along India's southwest coast, the kiddi prawn (Parapenaeopsis stylifera) supports a substantial fishery, known as "karikady fishery" due to its high demand in domestic and international markets. Following implementing "mechanised fishing prohibition," catch fluctuations observed in P. stylifera catches sparked widespread social unrest among stakeholders, who feared that unharvested prawns would be lost to the fishery when these prawns moved away from the coast during the monsoon season. The study derived scientific evidence for to distributional idiosyncrasy of the species with spatial distribution tracking, understanding the correlation of species movement and maturity with environmental parameters, and tracking the individual cohorts through population parameter analysis. Data for the study were collected from commercial vessels, experimental surveys, and analyses was supported by GIS software and SPSS foftware. 18 cruises in the RV Silver Pompano and 3 cruises in RV Matsyakumari at five depths (10, 30, 50, 70, 90 m) were conducted during 2016–2019 off Kerala, southwest coast of India and, and a spatial analysis of the experimental trawling data contributed to evaluating the impact of the environment on the distribution of the species. The study revealed that increased salinity has a statistically significant impact on the expansion of the species, as indicated by geographical data. P. stylifera prefers to settle in areas with high salinity and low temperatures, according to geographical studies. This study not only established that the perception that species migrate away from the coast is rational, but it also established that there is no resource loss as a result of the 'Monsoon trawl ban,' because current fishing methods are capable of catching the larger prawns that have migrated to deeper waters. The study reaffirmed the usefulness of "monsoon trawl ban" in ensuring the long-term viability of the "karikadi" fishery along the southwest coast by assisting in species recruitment during the monsoon season.
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Unraveling the spawning and reproductive patterns of tomato hind grouper, Cephalopholis sonnerati (Valenciennes, 1828) from south Kerala waters
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-undetermined fish were analysed. The female to male sex proportion was 9:1, and the fish reached a maximum total body length of 38.5 and 54.5 cm for females and males, respectively. The following microscopic stages were identified: immature, developing, ripe, running ripe/releasing, and spent in both males and females. Several asynchronous development patterns were observed in the studied gonads, including multiple oocyte stages and early and advanced stages of sexual transition. High gonadosomatic index (GSI) for both males and females was recorded in March, May, and November. Running ripe and releasing stages in females were identified in the months from March to June, which indicates the spawning season. The absolute and relative fecundity of the species ranged from 162,723 ± 207,267 and 239 ± 285, respectively. An exponential relationship was found between fecundity and total body length (TL), fecundity and total body weight (TW), and fecundity and gonad weight (GW).