Search

Diversity of intertidal macrobenthic community and environmental parameters namely temperature, salinity, pH and DO were assessed near the proposed nuclear power plant site Jaitapur from 2012 to 2014. Analysis of macrobenthic samples revealed the presence of 54 species belonging to 19 different groups. Highest diversity (14 groups) was observed during the post-monsoon (2014) season. At sandy and rocky shores, polychaetes were dominant followed by crustaceans like amphipod, isopod, penaeid shrimps and decapod larvae. Among all inshore stations, diversity was found to be maximum at Ganeshgule (N SW30 kms). Shannon-Weiner diversity index (2.259) and Margalefs species richness index (2.502) indicated rich diversity at rocky habitats (N SW30 kms). The present study suggests the stable environmental parameters around the Jaitapur Nuclear Power Plant (NPP) sites and is responsible for the rich benthic community. The outcome of the present study may be useful as baseline information on macrobenthos around the proposed Jaitapur NPP site. [ABSTRACT FROM AUTHOR]

Food and feeding habits of eight species of female elasmobranchs in gestation stages were studied. The low feeding intensity and smaller mean volume of food per fish (in ml) attributed with their gestating activities and cease feeding in the nursery region as protecting measures for young ones. The prey items occurred in guts content of these species were analyzed by index of relative importance (IRI). Carcharhinus macloti and Rhizoprionodon acutus (100 %) were piscivorous which feed exclusively on teleosts found above the bottom. Rhizoprionodon oligolinx (96.5 %) and Scoliodon laticaudus (50.3 %), were generalized predators, feeding throughout the water column and occasionally at bottom chiefly on teleost and small quantities of crustaceans and molluscs. Amphotistius imbricate (86.06 %), Rhinobatos annandalei (68.9 %) and Rhynchobatus djiddensis (61.58 %) were carnivores, feeding mainly on free-living crustaceans and supplemented by teleost at the sea bottom. Pastinachus sephen (76.59 %) showed a predacious carnivorous character exhibiting a tendency to feed mainly on bivalves along with small portion of crustaceans, teleost and mud by browsing at bottom. The prey organisms observed in stomach content of these species conferred with environment biota harvested by single and multi-days trawlers operating off Mumbai waters. [ABSTRACT FROM AUTHOR]

In developing countries, management of fisheries resources is directly or indirectly dependent on fish reproductive biology & conservation of the breeding grounds. Indian Oil Sardine fishery is a commercially important pelagic fishery along the coast of Mumbai. A Ganado-somatic index value of females was maximum (8.20) in September and minimum (0.38) in January. For males, the maximum Gonado-somatic index was 8.36 in September and the minimum 0.29 in February. Based on sex ratios month-wise, females were slightly more dominant in all months. There is a significant difference in the length-wise distribution of sexes, with a large number of females in higher length groups. Females attain the length at first maturity at 166.5 mm, and matured ovaries were seen in September and October, with a maximum percentage in September. It is estimated that the absolute fecundity ranged between 28,860 and 52,646, and the relative fecundity ranged between 450 and 684 number eggs per gram of fish weight. [ABSTRACT FROM AUTHOR]

The taxonomic ambiguity surrounding several prominent genera of sciaenid has been a long imepdiment to research to solve species-level confusion on this groups. This study has been conducted for a compehensive assessment of species and phylogenetic relationship within the species and between the species through a combined osteological and morpholigical approach. Twelve species belonging to seven genera of family Sciaenidae (Teleostei: Perciformes) from North West coast of Indian water were studied. A data set of 51 morphological characters (24 osteological, 23 morphometric and 4 meristic) was constructed. A cladistics analysis based on the osteological characters resulted in a single most-parsimonious tree of tree length of 63 steps, Consistency index (CI) = 0.6981 and Retention index (RI) = 0.6981. This cladogram did not support the monophyly of one of the seven genera, Otolithes. The osteological data set was then combined with a data set of 23 morphometric and 4 meristic characters that has been used for establishing phylogenetic relationship with greater nodal support of tree length of 124 steps, (CI=0.6855 and RI=0.7045). The topography of the cladogram is similar as obtained from osteological data alone except Otolithes cuvieri and O. ruber found closer than the Otolithoides biauritus. [ABSTRACT FROM AUTHOR]

The present investigation included diet composition and feeding habits of sin croaker (Johnius dussumieri) based on the monthly examination of 1031 specimens along Ratnagiri coast of India from December 2009 to November 2011. Results indicate that J. dussumieri is a carnivore feeder and feeds upon narrow range of food items. Crustaceans were identified as most dominant food items followed by teleost fishes, molluscs and planktonic forms like fish egg and Salpa. The species preferably feeds on a marine crustacean i.e. Acetes spp. The feeding intensity of J. dussumieri was found poor during April and September. The analysis of Kendell's coefficient of concordance indicated relatively stronger association (W = 0.64, p < 0.05) of choice of food items with season, while the same did not hold good for different size groups. Therefore, the differential feeding habit was evident among the different size groups. The juveniles preferably feed on crustaceans, while the adults were observed to prefer small teleost fishes. The differences in the diet composition between adults and juveniles indicated the existence of different feeding habitats along the Ratnagiri coast of India. [ABSTRACT FROM AUTHOR]

Johnius borneensis (Bleeker 1851) contributes substantially to the marine fishery of India. The stock structure analysis of the species is essential for its sustainable management and utilization. The study is based on 411 specimens of the species randomly collected from the commercial landings at four marine fish landing centres in India. A truss network with 28 distance variables, based on 10 landmarks, was developed utilizing the digital images of the specimens, by means of tps Dig2 and PAST software platforms. Multivariate test statistics - Mahalanobis distance, Wilks' lambda and Pillais' test indicated significant difference between the East coast stocks and some extent of mixing among West coast stocks. Truss measurements transformed for allometric variations were subjected to Canonical Discriminant analysis and bivariate plot between the canonical variables showed existence of different morphometric stocks of the species. Major truss distances that contributed to the delineation were that on the head and posterior region of the fish body. The truss morphometric traits, that best discriminated the stocks, were subjected to the discriminant function analysis which appropriately classified 80 % of the specimens to the particular location. The present study is the first account on the stock structure analysis of J. borneensis from India and will help in developing policies for the management of the fishery and the sustainable utilization of the resource. [ABSTRACT FROM AUTHOR]

A mass-balance trophic model for Zuari, a monsoon-influenced tropical Indian estuary, was constructed to understand trophic organization, to measure the ecosystem indicators and to assess the state of the ecosystem maturity and stability. Twenty-two functional groups were identified in the model starting from primary producers (trophic level = 1) to top predators (trophic level = 4.7). The estuarine food web is controlled by bottom-up control based on primary producers and detritus. Phytoplankton, zooplankton, clupeids & anchovies and heterotrophic benthos were observed as keystone species in the food web. A higher total system throughput (23333.9 t km-2 year-1 ), and lower dimensions for recycling capacity (Finn’s cycling index: 2.78 %), system omnivory index (0.25), and relative ascendency (39.9 %) were observed. Based on the ecosystem indices, Zuari estuary is relatively small, and developing ecosystem, which is resilient to the external disturbances on the system. This trophic model is the first Ecopath model for tropical monsoonal estuaries and fourth model for the estuaries along the Indian coast. The Zuari estuary model showed resemblance to the sub-tropical and tropical estuarine Ecopath models and differed from estuaries of India and temperate estuaries. This Ecopath model would be also useful for simulating the variations in trophic flows and biomass for functional groups under the impact of fishing and anthropogenic activities on the ecosystem. [ABSTRACT FROM AUTHOR]

The purpose of this study was to ascertain shell occupation patterns by the hermit crab; Diogenes alias found inhabiting the subtidal region of Mumbai, northwest coast of India. A total of 385 samples of D. alias, occupying different molluscan shells, were collected bi-weekly from trawling operations off Mumbai. The species was found to occupy the shells of 12 gastropods species, of which, the most commonly occupied shells were that of Tibia curta (38.7 %) followed by Indothais lacera (36.37 %) while the shells of Rapana rapiformis and Turris spp. were least occupied with 0.26 %. The diversity of shells occupied by male was higher than female and least in ovigerous females. A high correlation was found between the internal volume of shell and weight of hermit crab occupying it. The present study concluded that the shell architecture has influence on the shell occupation by hermit crabs. [ABSTRACT FROM AUTHOR]

The present communication deals with an attempt to differentiate species of hermit crabs, collected from Maharashtra region, using morphometric features. A total of 16 morphometric measurements features were recorded from each specimen. The morphometric features like cheliped dactylus length, cheliped propodus length, carapace length, ocular peduncle length, antennular peduncle length and propodal length have been found to be important traits in the separation of the species. Among these first three, cheliped dactylus length, cheliped propodus length and carapace length, are most important in differentiation. The analysis also indicated 99.55 % correct discrimination of the species based on selected traits. [ABSTRACT FROM AUTHOR]

The whale shark, Rhincodon typus (Smith, 1828) is reported to be the largest of all living fish. It inhabits either single or in group in near shore or open sea. The present communication highlights some of the behavioral activities of this species as not much information is available on the ethology of R. typus especially from Indian waters. This paper attempts to report the activities like scratching with boats, butting, feeding by sucking at cod end of dol net, inhaling water along with active pelagic fish and association with devil ray in the same ecosystem. Many of these behavioral studies are built upon by day to day association with experienced fishermen mainly from dol netters. Their unique capability to stay alive in dol net and gill net for a long time calls for their active role in ecosystem. [ABSTRACT FROM AUTHOR]

The present investigation on the different aspects of biology of white sardine Escualosa thoracata is based on the data collected from North-West coast of India from December 2017 to March 2019. The aspects covered in biological studies, growth and mortality parameters of the species and status of white sardine fisheries. The length-weight relationship was shows positive allometric growth of the species. Analysis of covariance indicated significant difference in regression slope of length weight relationship for males and females. Copepods was major food item indicating planktivorous feeding. The highest value for GaSI for male and female was recorded as 0.75 and 1.13 in November and March respectively. Length at first maturity for male and female was estimated to be 9.18 cm and 9.78 cm, respectively. The average absolute and relative fecundity was observed as 7282 and 721 ova per gram body weight, respectively. The highest value for GnSI for male and female was recorded as 9.15 and 5.05 respectively in March. The highest value for condition factor (K) for male and female was recorded as 1.39 and 1.54 respectively. In growth study, L∞, K and t0 was estimated as 129.5 mm, 2.16 yr-1 and -0.00911 years, respectively. Exploitation ratio (E) was found 0.56 along the North-West Coast that indicate, this particular fisheries is near to optimum exploitation along the North-West Coast. [ABSTRACT FROM AUTHOR]

Two closely related species Otolithes cuvieri, Trewavas, 1974 and Otolithes ruber, (Schneider, 1801) have been differentiated based on morphometric and meristic traits. A simple yet useful criterion based on a pair of canine teeth present on the upper and lower jaw as well as position of the mouth is currently used to differentiate two congeneric sciaenid fish species the O. cuvieri and O. ruber. Findings of the present study indicated that simply two morphometric and meristic characters are sufficient to differentiate these two species. MANOVA (Multivariate analysis of variance) and stepwise discriminant function were used to decide the morphometric traits, significant for differentiation of the species of family Sciaenidae. Discriminant function analysis revealed that 98 % of the species were correctly classified based on five morphometric characters namely Prepectoral fin length (PPFL), Pre-anal fin length (PAL), Post orbital head length (POHL), Post anal fin length (POAL) and Body depth (BD). The m-transformed morphometric traits were found to be useful tools in generating canonical variables in differentiating the species. The first canonical variables showed altogether 98 % variance. The scatter plots by first three canonical variables have well differentiated the species. Two meristic characters such as the number of gillrakers present on lower limb of first gill arch and figure of arborescent appendages on the swim bladder are important in differentiation of these species. [ABSTRACT FROM AUTHOR]