NOPR Collection:

First record of angry worm eel Skythrenchelys zabra (Anguilliformes: Ophichthidae) from the east coast of India

Mon, 01 Apr 2019 00:00:00 GMT

Title: First record of angry worm eel Skythrenchelys zabra (Anguilliformes: Ophichthidae) from the east coast of India Authors: Mohapatra, Anil; Ray, Dipanjan; Mohanty, Swarup R.; Mishra, Subhrendu Sekhar; Mohanty, Rajeeb K. Abstract: Skythrenchelys zabra (Castle and McCosker, 1999) a species belonging to the family Ophichthidae is reported for the first time from the east coast of India on the basis of 11 specimens collected from various fishing harbours along the West Bengal, Odisha and Andhra Pradesh coasts. The species was first described from south-west coast of India in the Arabian Sea. The present report extends the range of distribution of the species to the Bay of Bengal along the east coast of India. Page(s): 413-415

Macroalgae as indicator species for shore platform zones of Dwarka, Gujarat, India

Mon, 01 Apr 2019 00:00:00 GMT

Title: Macroalgae as indicator species for shore platform zones of Dwarka, Gujarat, India Authors: Sanghvi, Dimpal; Chaudhury, Nandini Ray; Jain, B. K. Abstract: Dwarka coast of Gujarat state in India has a stable shore platform. A study was carried out to identify indicator species among the sampled macroalgae to understand their spatial preferences on the shore platform zones. For this study, the shore platform was divided into three sections in north-south direction: Northern, central, and southern sections. These sections were further divided into three microzones in west-to-east direction based on their local geomorphology and tidal inundation characteristics for more detailed study. These microhabitat zones are: Cliff Base Zone (CBZ), Intertidal Mixed Zone (IMZ) and Subtidal Zone (STZ). To identify indicator species for each microzone, the shore platform was surveyed based on systematic random sampling for two years (April 2013 to April 2015). Line intercept transects and GPS-tagged photo quadrates were carried out from land to seaward as part of the sampling procedure. Indicator species were identified on the basis of a decision-rule when a single species belonged to only one microhabitat zone in all the three sections. Total 97 species of seaweeds were recorded in the shore platform of Dwarka. Out of these, 27 belonged to chlorophyta, 21 to phaeophyta and 49 to rhodophyta. Out of all these species, rhodophyta was found as the dominant group in the shore platform. Out of 97 species, only 12 species were identified as indicator species. Out of these, only one species was from phaeophyta group and eleven from rhodophyta group. This study shows indicator species of the microhabitat zones of the shore platform, with rhodophyta sp. as the prominent macroalgae group. Indicator species can act as proxy indicators of the microhabitats created by the local geomorphology and tidal regime on the shore platform. Page(s): 416-422

Population dynamics and stock assessment of spadenose shark Scoliodon laticaudus Muller and Henle 1839 along Gujarat coast of India

Mon, 01 Apr 2019 00:00:00 GMT

Title: Population dynamics and stock assessment of spadenose shark Scoliodon laticaudus Muller and Henle 1839 along Gujarat coast of India Authors: Sen, Swatipriyanka; Chakraborty, S.K.; Vivekanandan, E.; Zacharia, P.U.; Kizhakudan, Shoba J.; Jaiswar, A.K.; dash, Gyanaranjan; Jayshree, G.; Bharadiya, Sangita A. Abstract: Stock assessment of Scoliodon laticaudus Muller and Henle, 1839 was made along with analysis of its few biological characteristics from its commercial landings during 2012-2016 from Gujarat waters of India to understand the population dynamics and stock status of the species. The average annual landing of the species was 5442 t, which constituted about 67% of the total shark landings at Gujarat coast. L_∞,K and t₀ were estimated as 75.53 cm and 0.54/yr, and -0.4 yr, respectively. Total mortality rate, fishing mortality rate and natural mortality rate were estimated as 1.95 yr^-1, 1.04 yr^-1 and 0.91 yr^-1, respectively. The length at capture (Lc₅₀) and length at maturity (Lm₅₀) were 39.74 cm and 35.79 cm, respectively, which indicate that most of the sharks are exploited after attaining the sexual maturity. Length-weight relationship showed that the growth was isometric. The species was a continuous breeder and showed peak recruitment during September. The current exploitation ratio (E_cur) was found to be 0.53, which is lower than E_0.1estimated for the species using Beverton and Holt yield per recruit analysis. Thompson and Bell prediction model showed that maximum sustainable yield for S. laticaudus could be obtained by increasing fishing effort by almost 2.4 times higher than the present level which would deplete the spawning stock biomass (SSB) to 20%. Maximum economic yield could be obtained by increasing the fishing effort by 1.8 times which would also decrease the SSB, but to a comparatively safer 26.5% level. Considering 30% SSB as a precautionary management reference point, the effort could be increased by 50% exclusively for the sharks to increase the yield and revenue from fishery while maintain SSB at a safer 30% level. Page(s): 423-433

Stock structure analysis of Splendid ponyfish Eubleekeria splendens (Cuvier, 1829) along Indian coast using truss network system

Mon, 01 Apr 2019 00:00:00 GMT

Title: Stock structure analysis of Splendid ponyfish Eubleekeria splendens (Cuvier, 1829) along Indian coast using truss network system Authors: Rawat, Shobha; Benakappa, S.; Pazhayamadom, Deepak George; Kumar, Jitendra; Soman, Chitra; Venugopal, R. Abstract: Eubleekeria splendens (Cuvier, 1829) also called Splendid ponyfish, is commercially important and has wide distribution along the Indian coast. The species shows dominance along the south-west and south-east coast but there is no detailed information on the stock structure available from Indian waters. Therefore the present study focused on understanding the stock structure based on putative spawning stock. Fish samples were collected from five locations: Three from the west and two from the east coast. Twenty-four morphometric variables were measured using a box-truss network method. Principal component analysis delineated the population into east and west coast stocks. With respect to locations, each sampling unit formed separate clusters, thus representing isolated stocks. The samples from Mangaluru produced a single clustering with Kozhikode samples indicating that the morphological profiles of these two populations are homogeneous. Multiple comparisons on the factor scores indicated two independent stocks on the east coast, whereas the ﬁshery on the west coast is replenished by a single stock on south-west coast but a separate stock on the north-west coast. Thus, information on the spatial structure of phenotypic stock makes it mandatory to understand the biology and dynamics of these isolated stocks of E. splendens separately and thereby a traditional stock assessment should be performed to estimate current resource status stock-wise in terms of biological reference points. Page(s): 434-443