Indian Journal of Geo-Marine Sciences (IJMS)

Report on commensal shrimp Ensiger custos (Forskål, 1775) (Caridea: Palaemonidae) associated with bivalve Pinna bicolor Gmelin, 1791 in Palk Bay, India

S Prakash — 2024-10-09

For the first time, a Pinna shell associated shrimp Ensiger custos was documented from the shallow seagrass beds of Palk Bay, India. The shrimp specimen was identified based on the morphological characteristics such as chela of the first pereiopod cannulate, absence of distal teeth on the rostrum, antennal spine minute and dactylus of the second pereiopod with single large triangular tooth in the proximal half. The E. custos was found to be closely related to E. custoides. In the present study, E. custos shrimp was found associated with Pinna bicolor Gmelin 1971.

Additional records of the deep-sea scissor-foot shrimp Psalidopus huxleyi Wood-Mason & Alcock, 1892 (Decapoda: Caridea: Psalidopodidae) from the Arabian and Andaman Seas, India

Kuberan G — 2024-10-09

In this paper, a taxonomic account of the rare deep-sea caridean shrimp Psalidopus huxleyi Wood-Mason & Alcock, 1892 is provided based on four specimens collected during exploratory cruises onboard the “Fishery Oceanographic Research Vessel Sagar Sampada” in the Andaman Sea (635 meters depth) and the Southeastern Arabian Sea (957 m). This species has often been recorded from the Western Pacific Ocean, but this study represents the rediscovery of the species from localities close to the type localities since its original description.

Evaluation of the status of marine fishery resources of Tamil Nadu, India using surplus production models

R Abinaya — 2024-10-09

The present study used surplus production models for the assessment of fisheries stock and to evaluate the marine fishery status of Tamil Nadu. Present study computed and analysed annual catch and effort between 1998 and 2018 using Catch Effort Data Analysis (CEDA) software. The mean annual catch of Tamil Nadu marine fisheries was 4.14 lakh tonnes, ranging from 2.87 lakh tonnes (2005) to 5.20 lakh tonnes (2018). The Biological Reference Points (BRP), such as Maximum Sustainable Yield (MSY), Biomass at MSY (B_MSY), and Fishing mortality at MSY (F_MSY), were estimated using three error assumptions (Normal, Log Normal and Gamma) of Fox, Schaefer, and Pella-Tomlinson production models for Initial Proportion (IP) ranging from 0.1 to 1. From the results, MSY, B_MSY and F_MSY estimated by the best fit Schaefer-Log Normal (IP value of 0.8) were 5.32 lakh tonnes, 35.3 million tonnes and 0.151, respectively. The BRP determined from the Schaefer and Pella-Tomlinson models was similar. The predicted MSY values were higher than the most recent catch (5.20 lakh tonnes) of 2018. According to the reference point results, the stocks are secure; however, it is advised to keep fishing at present level in order to preserve the stock at a nearly optimal fishing pressure.

Molecular marker (RAPD and RFLP) analysis of Mullet species

I Vidhya — 2024-10-09

Mullet species belongs to the family, Mugilidae. Traditional taxonomic characters failed to differentiate mullet species due to the possibility of cryptic species and morphological similarity among mullet species. This study aimed to differentiate the selected mullet species using molecular markers. A total of 95 mullet samples (M. cephalus, P. macrolepis, and P. tade) were collected from Tamil Nadu and Kerala. For this study, 5 RAPD primers (OPA1, OPA10, OPA11, OPA15, and OPA16) were chosen from a set of 30 universal primers. The Nei’s unbiased genetic distance was calculated with the help of the software “POPGEN version 1.32”. The genetic distance between P. tade and P. macrolepis was lower, while the distance between M. cephalus and P. tade was greater, measuring 43.37 %. For the PCR-RFLP marker, the restriction enzyme was chosen based on in-silico analysis. The Alu I enzyme displayed species-specific patterns in M. cephalus at 190 bp, 200 bp, and 210 bp for the 16S rRNA gene.

New records of soft corals (Cnidaria: Octocorallia) at Digha and adjacent areas, West Bengal, India

J S Yogesh Kumar — 2024-10-09

A comprehensive and thorough research study was undertaken in Digha and the neighbouring coastline of West Bengal to investigate the benthic communities in the area. The survey identified a total of 16 species, including 12 previously unrecorded soft coral species at the study sites. As a result of this investigation and considering the existing data, the total number of octocoral species in the region has been revised to 20 species. This research contribution, specifically documented the new record of 12 soft coral species, i.e., Dendronephthya ganjamensis Henderson, 1909; Carijoa riisei (Duchassaing & Michelotti, 1860; Muricella ramosa Thomson & Henderson, 1905; Acanthogorgia muricata Verrill, 1883; Menella sp.; Subergorgia suberosa (Pallas, 1766); Acanella robusta Thomson & Henderson, 1906; Junceella juncea (Pallas, 1766); Verrucella umbracula (Ellis & Solander, 1786); Lituaria hicksoni Thomson & Simpson, 1909; Pteroeides punctatum Thomson & Simpson, 1909; and Pennatula indica Thomson & Henderson, 1906 within the study area.