Indian Journal of Geo-Marine Sciences (IJMS)

A note on occurrence of blanket octopus, Tremoctopus gracilis (Cephalopoda: Tremoctopodidae) from Northwestern coast of India

S Ragul, M Ketan, H L Parmar, J B Solanki, G Mahadevan — Fri, 09 Jan 2026 00:00:00 +0530

This study reports the occurrence of the blanket octopus, Tremoctopus gracilis (Souleyet, 1852) from the Gujarat, northwest coast of India, indicating its range extension to the northern Arabian Sea. A single female specimen (535 mm TL and 148 mm DML) was collected from the multiday trawl by-catch landed at the Veraval fishing harbour in February 2024. Details on systematics and morphological description of this species are presented herein.

Range extension of Günther's waspfish, Snyderina guentheri (Boulenger, 1889) (Synanceiidae: Tetraroginae) from Gujarat, Northeastern Arabian Sea

J B Solanki, H L Parmar, P V Parmar, H V Parmar, S Ragul — Fri, 09 Jan 2026 00:00:00 +0530

From May 2023 to May 2024, a regular fishery survey was conducted to evaluate the trawl bycatch of Veraval fishing harbour, on the northwestern coast of India. A total of five specimens of Günther's waspfish, Snyderina guentheri (Boulenger, 1889) (108.9 – 155.0 mm SL) were sorted out from the low-value bycatch. Previously, S. guentheri was only known from the south (Quilon, Kerala) and east (Vishakhapatnam, Andhra Pradesh) coast of India. This study reports its range extension towards the north-eastern coast of the Arabian Sea with detailed morphometric measurements, meristic counts, distribution and radiograph of the reported species, along with a key to its genera.

Mining salt pan soil metagenome for functional screening of enzymes

N M Raiyani, K G Dangar, S P Singh — Fri, 09 Jan 2026 00:00:00 +0530

Metagenomics relates to the uncultivable microbial world, targeting the total microbial genetic material in a specific environment. While a few extreme habitats have been studied for the metagenomic diversity and biotechnological potential, the saline systems of India have not been much explored. This study describes direct DNA extraction methods based on the physical, chemical and enzymatic lysis in various combinations to extract the metagenomic DNA. Metagenomic DNA extracted from salt pan soil has a high molecular weight. Four small insert metagenomic libraries were constructed using two different vectors pUC18 and pET 21a⁺, and E. coli JM109 as the host organism. The libraries were further screened for protease, amylase and lipase. Seven protease and five amylase positive clones were detected, and the relative enzyme activities were assessed. The metagenomic library from the salt pan soil proved to be significant for the exploration of valuable enzymes.

Present status and distribution of the family Syngnathidae at the Hooghly-Matlah estuarine system with some conservation aspects

D Bhakta, R K Manna, B K Das, S M Nair, T Kayal, S Samanta — Fri, 09 Jan 2026 00:00:00 +0530

The Syngnathidae family, comprising of pipefishes, seahorses, and seadragons, frequently occurs in marine, estuarine, and occasionally in freshwater environments. The Hooghly-Matlah estuary in West Bengal, India, is characterised by tidal dynamics, a salinity gradient, and rich biodiversity, making it an ideal habitat for many fish species, including multiple syngnathid species adapted to brackish water environment. Sampling in the Hooghly-Matlah estuary system was carried out between 2021 and 2023, which encountered altogether three syngnathid species. Pipefishes are designated as Least Concern, while seahorses are listed as Vulnerable (VU) in the IUCN Red List. Syngnathids are largely used in trade, and because of their rapidly declining populations, several countries have prohibited their exports. Among the three species (Hippichthys spicifer, Hippocampus trimaculatus, and Microphis cuncalus), only one species (Microphis cuncalus) was barcoded, and the sequence is submitted to the GenBank with accession number OP090589.1. Even though some syngnathids live only in marine habitats, the Hooghly-Matlah estuary supports a few of these species; consequently, proper conservation plans and management measures should be implemented to ensure their long-term sustainability.

Genetic identity, allometric traits, and gastro-somatic index of Chromis viridis in Agatti Island, Lakshadweep: Implications for conservation

M U Rekha, T Haslamathbi, S Bharathi, S Akash, U K Sarkar, T T Ajith Kumar — Fri, 09 Jan 2026 00:00:00 +0530

Chromis viridis, a key live bait fish, being used for the pole-and-line tuna fishery of Lakshadweep, plays a vital role in the sustainability of the said traditional fishing practice. Given its ecological and economic importance, understanding the speciesˈ biological and genetic characteristics is essential for effective management and conservation. This study presents the first gender-specific analysis of Length-Weight Relationship (LWR), condition factors, and Gastro-Somatic Index (GaSI) of C. viridis, alongside genetic characterisation using mitochondrial cytochrome c oxidase subunit 1 (CO1) and 16S rRNA gene markers. Specimens were sampled monthly from March 2022 to February 2023. Results revealed distinct seasonal and sex-specific growth patterns. Males exhibited isometric growth (b ≈ 3) in February, April, October, November, and December, while females showed similar growth in March, April, September, and November. Negative allometric growth (b < 3) observed for both sexes indicate fluctuations in energy allocation potentially linked to spawning cycles and environmental variability. The condition factors: Fulton condition factor (K), allometric condition factor (K_A), and relative condition factor (K_R) varied seasonally in both sexes. GaSI values fluctuated throughout the year, reflecting seasonal changes in feeding intensity. Both sexes showed peak GaSI in April, May, and October. Notably, females consistently exhibited higher GaSI values than males, suggesting more energy investment in feeding, which is likely to support oogenesis. These findings provide critical insights into the growth dynamics and physiological responses of C. viridis, contributing valuable data for species-specific, sex-oriented conservation and fisheries management strategies.