Morphometric differentiation of hermit crabs, superfamily: Paguroidea from Mumbai, North-West coast of India

492-495The 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

First record on the absence of anal fin in the white sardine, Escualosa thoracata (Valenciennes, 1847) from Indian waters

White sardine, Escualosa thoracata (Valenciennes, 1847) forms a minor fishery along the west coast of India. An abnormal specimen of white sardine, lacking anal fin, was collected from Mangalore coast along with the normal specimens. The characters of the abnormal specimen are described along with normal specimens. The report is the first of its kind for E. thoracta from Indian waters. The possible causes of the abnormality in this species have been discussed in this communication

Morphometric and meristic variation of congeneric sciaenid fishes Otolithes cuvieri Trewavas, 1974 and Otolithes ruber (Schneider, 1801) from Maharashtra, west coast of India

80-86Two 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 Pre-pectoral 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

Evaluation of Economic Impact on Juvenile Landings of Cephalopods in Mumbai Waters, Northwest Coast of India

Economic assessment of juvenile landings of 5 dominant cephalopods at New Ferry Wharf (NFW) landing centre, Mumbai was carried out during January to December, 2013. Dominant cephalopod fishery recorded include one species of squid, Uroteuthis (P) duvaucelii, three species of cuttlefishes, Sepia elliptica, Sepia pharaonis, Sepiella inermis and a species of octopus, Cistopus indicus together contributing 98% of total cephalopod landings. Estimated total annual economic gain calculated using bioeconomic model was Rs. 33.22 crores with estimated biomass gain of 4995 t per annum, if juveniles are allowed to grow up to length at first maturity (Lm)/Lmean. Among five species, C. indicus contribute maximum with 64.07 % of average juvenile catch followed by U. (P) duvaucelii (26 %), S. elliptica (23.63 %), S. inermis (23.27 %), and S. pharaonis (12.85 %). On these resources, while in S. inermis, both Lm equals Lmean indicates breakeven point for the species. The study revealed that peak spawning season of these species coincides with peak juvenile landings which may result in reduction of overall size range thus will lead to loss of fishery in economic as well as ecosystem regime. The study indicates the improvement of harvest biomass by 2.95 times which would result in generating additional revenue to the fishers by a margin of 3.71 times; if juveniles are allowed to grow up to Lm/ Lmean whichever is greater. Based on finding of present study management measures such as temporary fishing holidays at juveniles fishing grounds, feeding grounds and spawner abundance grounds which in turn allow these high valued species to contribute to the fishery with high economic gain and sustainable utilization of the resources may be adopted

A record of anopthalmia in Mystus tengara (Hamilton, 1822) from Assam

An abnormal case of anopthalmia in a striped catfish Mystus tengara (66.8 mm in standard length) from Assam is reported in this communication. Thirty eight morphological characters of the abnormal specimen were also studied and compared with normal specimens to observe variation in the morpho-meristic traits, if any. In the abnormal specimen, the proportionate height of the dorsal fin (31.1 mm) and nasal barbel length (75.9 mm) was found to be higher compared to that of the normal specimens (21.6 – 26.5 mm and 47.9 – 72.5 mm, respectively). While the body depth of anus was higher in case of normal specimens (19.1 – 29.2 mm) compared to abnormal specimen (14.5 mm). However, no marked variation was observed in meristic characters. This anomaly does not seem to have affected morphological aspects. Factors like weed infestation, pesticide and herbicide application adversely affecting the habitat is believed to be the cause of such deformity. The abnormality does not seem to have affected the overall growth of the fish

Length-weight relationship of selected commercially important marine fishes from east coast of India

The paper deals with length-weight relationship (LWR) of selected commercially important marine fishes from the east-coast of India. Samples were collected fortnightly from experimental fishing using trawl operated at depth up to 70 M off Vishakhapatnam coast on the east-coast of India during 2015-17. Measurements of total length (TL) (nearest to 0.1 cm) and body weight (nearest to 0.1 g) of individual fish were taken. The LWR showed good fit with r2 values ranging from 0.975 for Lepturacanthus savala Cuvier, 1829 to 0.999 for Upeneus vittatus Forsskål, 1775. The ‘b’ values ranged from 2.618 for Photopectoralis bindus Valenciennes, 1835 to 3.186 for L. savala Cuvier, 1829

Relative condition factor and food and feeding of Jones’ pony fish Eubleekeria jonesi (James, 1971) from Mandapam waters, Tamil Nadu, India

The relative condition factor (Kn) based on length-weight relationship and food and feeding habits of Jones’ pony fish Eubleekeria jonesi  (James, 1971) off Mandapam waters was studied during December 2016 - April 2018. The Kn values showed variations on a monthly basis with maximum value during September (1.23) for male and March (1.53) for female. Analysis of fullness of stomach of 961 samples within the size range of 51-130 mm revealed 40.87% fishes as actively fed, 36.19% as moderately fed and remaining 22.94% as poorly fed. The monthly mean fullness index (FI) was highest during September for both sexes. Highest gonadosomatic index (GSI), vacuity index (VI) and Kn value were observed during March-April in females, probably indicating a spawning peak and hence meagre feeding, which resulted in lowest fullness index (FI). Fishes of smallest length group (51-70 mm) had highest FI and minimum VI and vice versa. The values of index of relative importance (IRI) indicated that the species was planktivorous as well as detritivorous, with top priority towards crustaceans (27.6%) followed by bivalves (23.6%), foraminifera (15.4%), phytoplankton (12.5%), gastropods (9.1%) and nematodes (8.3%) in the gut contents. Diet did not show significant variation either sex-wise or size-wise

Occurrence and abundance of plastic particles in razor moonfish along the eastern Arabian Sea

Rising crisis in marine environment is the presence of plastics in the water column and risk of their input and accumulation in the food web. The present study reports for the first time, the presence of micro and macro plastics in the gut of razor moonfish, Mene maculata. Moonfish plays a major role in the marine food web as prey of large pelagic fishes. The gut analysis of fishes collected from commercial vessels operating along eastern Arabian Sea was analysed to determine the occurrence and abundance of plastic particles with attempt to identify the diet component which might have contributed to the plastic intake in fish. The analysis revealed dominance of plastic particles in gut when dietary component was dominated by eggs. The present study forms baseline information for plastic accumulations in fishes along the eastern Arabian Se

Shell occupation pattern by the hermit crab Diogenes alias McLaughlin & Holthuis, 2001 (Diogenidae) from Mumbai, India

766-773The 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

Biometric analysis of brushtooth lizard fish Saurida undosquamis (Richardson, 1848) from Mumbai waters

The aim of the present study was to investigate the relationship between various morphometric measurements and meristic counts, and to establish the length-weight relationships (LWRs) and length-length relationships (LLRs) of Saurida undosquamis based on specimens collected from New Ferry Wharf landing centre of Mumbai coast during September 2013 to June 2015. The morphometric variables for the species under study exhibited high level of correlation with each other. Based on present study results, the fin formula of S. undosquamis in Mumbai water can be written as B 13-15, D 11-13, P 13-15, V 9, A 10-11, C 18-20, L47-53. Different values of regression coefficient (b) and correlation coefficient (r) in LLRs illustrates that different organ grows differently. The values of the regression coefficient b in the LWRs equations (W = aLb) were 2.90, 3.04 and 2.99 for male, female and pooled individuals respectively indicating an isometric growth with high correlation coefficient (r2). These parameters are useful for evaluating the relative condition of fish as well as for subsequent biological and population based studies