Landmark-based morphometric and meristic variations of endangered mrigal carp, Cirrhinus cirrhosus (Bloch 1795), from wild and hatchery stocks

Wild stocks of endangered mrigal carp, Cirrhinus cirrhosus (Bloch 1795), continues to decline rapidly in the Indo-Ganges river basin. With an objective to evaluate its population status, landmark-based morphometric and meristic variations among three different stocks viz., hatchery (Jessore), baor (Gopalganj) and river (Faridpur) in Bangladesh were studied. Significant differences were observed in 10 of the 15 morphometric measurements viz., head length, standard length, fork length, length of base of spinous, pre-orbital length, eye length, post-orbital length, length of upper jaw, height of pelvic fin and barbel length, two of the 8 meristic counts viz., scales above the lateral line and pectoral fin rays and 10 of the 22 truss network measurements viz., 1 to 10, 2 to 3, 2 to 8, 2 to 9, 2 to 10, 3 to 4, 3 to 8, 4 to 5, 4 to 7 and 9 to 10 among the stocks. For morphometric and landmark measurements, the 1st discriminant function (DF) accounted for 58.1% and the 2nd DF accounted for 41.9% of the among-group variability. In discriminant space, the river stock was isolated from the other two stocks. On the other hand, baor and hatchery stocks formed a very compact cluster. A dendrogram based on the hierarchical cluster analysis using morphometric and truss distance data placed the hatchery and baor in one cluster and the river in another cluster and the distance between the river and hatchery populations was the highest. Morphological differences among stocks are expected, because of their geographical isolation and their origin from different ancestors. The baseline information derived from the present study would be useful for genetic studies and in the assessment of environmental impacts on C. cirrhosus populations in Bangladesh

Notes on yellow-spotted moray eel, Echidna xanthospilos (Actinopterygii: Anguilliformes: Muraenidae), from Great Nicobar Island, India

A single specimen of Echidna xanthospilos (Bleeker, 1859) was captured off Great Nicobar Island. This finding represents a new addition to the muraenid fauna of India. This is one of the data-deficient species hitherto known only from five countries in the Indo–Pacific. The specimen is described and illustrated

Additions to the Opisthobranch Fauna of Nicobar Group of Islands, India

319-322Opisthobranchia (Phylum: Mollusca) are one of the least studied groups in India, and very little is known from remotely located islands like Nicobar. Recent marine faunistic surveys conducted at Nicobar Group of Islands in the intertidal and subtidal zones revealed the presence of four opisthobranchs viz. Phanerophthalmus smaragdinus (Ruppell and Leuckart, 1828), Dendrodoris nigra (Stimpson, 1855), Phyllidiopsis krempfi Pruvot-Fol, 1957 and Herviella mietta Marcus & Burch, 1965 which are herein reported as new distributional records to Nicobar group of Islands and morphological descriptions of all the four reported species are enumerated

Notes on Pemphis acidula J.R. Forst. & G. Forst. (Myrtales: Lythraceae) from Andaman Islands, India

Pemphis acidula Forst. (Lythraceae) has been reported herein with locality data after a lapse of 91 years from Andaman Islands. This re-discovery is significant as P. acidula has not been added to the mangrove flora of India in many important national and international status reports. This species is characterized by its narrowly elliptic to lanceolate leaves that are densely covered with silky hairs on both surfaces, crumpled white petals, capsule with circumscissile dehiscence and winged seeds. Further, new morphological discoveries viz., tetramerous and pentamerous flowers were reported in the present study in contrast to the perfect hexamerous flowers reported elsewhere. Since P. acidula is sparsely distributed, location-specific conservation strategies should be adapted in order to prevent its local extinction from the Islands. In addition, exploratory surveys are imperative particularly in calcareous rocky habitats for authenticating the wider distribution of such rare species. </div

Temperature physiology in grouper (Epinephelinae: Serranidae) aquaculture: A brief review

Grouper aquaculture has emerged as a promising food production sector on the basis of the belief that it can lessen the pressure on overfished populations, particularly in the Asia–Pacific. This review provides an outline of the temperature physiology of aquacultured groupers in tropical and sub-tropical regions as described in 34 research articles published between 1979 and 2018. A total of 24 grouper species (i.e., 23 Epinephelus spp. and 1 Cromileptes sp.) and 4 hybrids (Epinephelus spp.) were reported to be aquacultured for temperature physiology studies; among these species, five are considered threatened (three are vulnerable species, one is critically endangered, and one is endangered). More than half of the species (n = 13, 54 %) were categorized as “Least Concern,” while five species were considered “Data Deficient.” The overall test temperatures applied across the different life stages of the aquacultured groupers ranged from 13 °C to 35 °C, with a mean optimum rearing temperature of 26.32 °C ± 0.62 °C. The majority of the experimental studies demonstrated that a rearing temperature of 28 °C could be optimal for grouper hatcheries in the Asia–Pacific. Although comparative experimental studies on the mean daily growth of groupers showed higher increments in recirculating hatchery tanks compared with those in floating net cages in the tropics, temperature alone may not completely govern the grouper physiology. In-depth research is imperative for precise predictions of the future prospects of sustainable grouper aquaculture, especially in the tropics