The reproductive biology and diet of the longtail butterfly ray Gymnura poecilura is described based on 630 specimens (N = 377 females and 253 males). The mean disc width (WD) of females and males was 576.7 mm (range = 190–920 mm) and 416.3 mm (230–550 mm), respectively. Sexual dimorphism in size was seen, with the maximum size of males being only 60% of the maximum female size. The disc widths at 50% maturity (WD50) were estimated to be 506.5 mm (females) and 435.9 mm (males). The mean uterine fecundity was 3.3 (range = 1–8). The size at birth was between 190 and 220 mm WD. Year-round reproduction was indicated, due to the presence of mature males and gravid females throughout the year, neonates in multiple months and large variations in embryo size within months. Feeding intensity increased with body size. Fish accounted for 80.9% of the diet (Index of Relative Importance, IRI), followed by crustaceans (18.9%) and molluscs. The species was found to be a specialized feeder.
A new species of the squat lobster genus Eumunida Smith, 1883 (Chirostyloidea: Eumunididae), E. multispina, is described and illustrated primarily on the basis of two male specimens from the Arabian Sea off the Kerala State, southwestern India, at depths of 250–400 m. One specimen from Lakshadweep, previously identified with E. funambulus Gordon, 1930, is also referred to the new species. The new species is morphologically most similar to E. funambulus among the 29 known congeners, but the presence of four epigastric spines and more numerous lateral spines on the carapace (four on the anterolateral and seven to 10 on the branchial margins) immediately distinguish the new species from E. funambulus. Genetic analysis using the mitochondrial COI and 16S rRNA markers also indicates that the new species is distinct from congenerics for which the sequence data are available.
Trawl fisheries sector account more than 50% of the marine fisheries production of India. Annual average fish landing from trawlers was 17, 21, 000 t (2008-2011), which formed around 51 % of the marine fish landing of the coast. In this about 51% of the catch was contributed by the west coast and remaining by the east coast of India. Recent studies of the trawl fishery in India have shown that incidental catches/low value bycatch (LVB) landing and utilization has increased over the period of time. The present study is based on the data collected from major trawl landing centres along the coast of India during the period 2008-2011.The estimated landing of low value bycatch (LVB) in trawl fisheries, increased from 14 % in 2008 to 25 % in 2011, which is reflected as reduction in discard volume by trawlers. On an average the highest quantity of LVB landed was in Veraval (50,000 t) and in Mangalore, LVB landing increased from 3% in (3000 t) in 2008 to 26 % (12,000 t) in 2011.In Mumbai, the percentage of trash fish landed remained around 5% during the study period. In Calicut, the LVB landed in 2011 contributed 26% to the total landings by the trawl. In Kochi, Kerala the total LVB landed in 2011 was 1,992 t forming 7.2 % of the total landing. In Chennai, Tamilnadu, the LVB landing which was 13 % in 2008 increased to 17% in 2011, while in Visakhapatanam, Andhra Pradesh, LVB landing showed a steady increase from 2% in 2008 to 21% in 2011. The landing centre price for LVB showed an increasing trend due to increased demand for trash fish for the production of fish meal and fertilizer. The dominance of finfishes in LVB found to increase the value of LVB and the value realized for 30,000 t of LVB in Mangalore in 2011 ( Rs.280 million) was more than that realized for 50,000 t of LVB in Veraval (Rs.200 million). A disturbing trend observed from the studies in Mangalore was that, the sardines in trash fetches higher price in some seasons (upto Rs.16/kg) compared to a lower price when landed in fresh form, and the percentage of sardines in LVB is found to be very high (24% in 2010). This trend may cause a severe threat to the protein availability to the rural poor. Looking at the trend of trawl landing during 2008-2012, it is seen that even though the trawl landing showed an increase over the period of time, the edible portion of the trawl landing did not show any significant increase rather showing general declining trend. Study on the bycatch from different centres along the coast of India showed that as many as 237 species / groups of marine fauna with juveniles of commercially important fishes were landed as LVB. Increase in utilization of LVB (which was discarded earlier) from trawl fishery, a trend which is market driven and its implication on the ecosystem and marine fisheries production of the country is discussed in this paper.
A biomass dynamics modelling study to derive biological reference points and management requirements of 223 commercially important fish stocks in different maritime states of India was conducted. Two decades (1997–2016) of fishery-related data on the harvest of resources by different types of fishing fleets formed the input. The multigear nature of the fishery situation was solved by introducing a gear standardization parameter into the biomass dynamics model. The relative positions of the fish stocks were depicted through Kobe plots generated for the ten maritime states/union territory, and the fish stocks were categorized, based on the status, into sustainable, overfished, recovering, and overfishing. The results indicate that 34.1% of the assessed fish stocks in the country are sustainable, 36.3% are overfished, 26.5% are recovering, and 3.1% are in the overfishing status. Regionally, the percentage of sustainable fish stocks were high along the southwest coast (51.6%), overfished stocks were high along the northwest coast (54.2%), and recovering fish stocks were high along the northeast coast (47.8%). The national mean B/BMSY was estimated as 0.86, which is a strong reason for strengthening fisheries management. Fishing fleets harvesting overfished stocks were examined for each maritime state, and recommendations regarding reduction in annual fishing hours are made.
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