New distributional records of deep-sea sharks from Indian waters

This paper reports the first documented record of three deepwater sharks from Indian waters i.e., Hexanchus griseus (Hexanchidae), Deania profundorum (Centrophoridae), pygmy false catshark (undescribed) (Pseudotriakidae) and presents a taxonomic account of smooth lanternshark, Etmopterus pusillus (Etmopteridae) and leafscale gulper shark, Centrophorus squamosus (Centrophoridae), caught by hooks & line units operated in the Arabian Sea, west coast of India and landed at Cochin Fisheries Harbour (Kerala), southwest coast of India

Hysteresis Modeling of Amplified Piezoelectric Stack Actuator for the Control of the Microgripper

This paper presents Bouc-Wen hysteresis modelling and tracking control of piezoelectric stack APA120S. The actuator is used to control a microgripper. A modified Bouc-Wen non-symmetric model is applied to study the behaviour of the system in static and dynamic state. The good agreement between predicted and measured curve showed that the Bouc-Wen model is an effective mean for modelling the hysteresis of piezoelectric actuator system. Subsequently, the inverse Bouc-Wen model is formulated and applied to cancel the non-linear hysteresis. In perspective of a control design, it is desirable to linearize the non-linear Bouc-Wen model to produce a static system. Finally, in order to increase damping of the actuator system and to improve the control accuracy, a cascaded PID controller is designed with consideration of the dynamics and static behaviour of the actuator. Experiment result shows that error is of only 5% if PID is cascaded with hysteresis compensation. Therefore, hysteresis compensation with PID controller greatly improves the micromanipulation accuracy of the microgripper actuated by piezoelectric stack

Rare landing of a large sized Indian halibut, Psettodes erumei (Bloch & Schneider, 1801)

The fishery of Indian halibut, Psettodes erumei (Bloch & Schneider, 1801) declined considerably in the recent past. In recent years their fishery was very sporadic and catches were represented by relatively smaller fishes below 30-40 cm along the the southwest coast of India. In August 2010 a large sized Psettodes erumei measuring 60 cm TL was observed at Cochin Fisheries Harbour, Kerala. The reported maximum size of the species is 64 cm TL

Macro Flora & Fauna of the Gulf of Mannar a checklist

The Gulf of Mannar (GoM) located along the south eastern tip of India falls in the Indo-Pacific realm and is one of the richest regions in the world from a marine biodiversity perspective. The region has a distinctive socio-economic and cultural profile shaped by its geography. It has an ancient maritime history and was famous for the production of pearls, an important item in trade with the Roman Empire as early as the first century AD. Rameshwaram along the GoM with its links to the legend Ramayana is an important pilgrim centre. The region has been and continues to be famous for its production of Indian sacred chanks. It has unique ecosystems mainly consisting of coral reefs, sea grass beds, salt marshes and mangroves which constitute important habitats for many species of commercially important finfishes and shellfishes. The GoM was established as a Biosphere Reserve (the first marine biosphere reserve in south and south east Asia) by 1989 by the Indian Government and the state of Tamil Nadu. A biosphere reserve is an area that is indented to secure the fundamental diversity of life in a region while continuing to advocate in economic growth. The overall objective of this Marine Biosphere Reserve is to conserve the Gulf of Mannar's globally significant assemblage of coastal and marine biodiversity and to integrate biodiversity conservation into coastal zone management plans. Thus, the GoM in addition to being a national priority also assumes global significance

DNA sequence information resolves taxonomic ambiguity of the common mud crab species (Genus Scylla) in Indian waters

For several years, mud crabs of genus Scylla have been misidentified owing to their high morphological plasticity and the absence of distinct morphological diagnostic characters. The taxonomic confusion of genus Scylla de Haan is considered to be a primary constraint to the development of aquaculture. Although genus Scylla was revised using morphological and genetic characteristics, taxonomy of Scylla species occurring in India is still not clear. In this study, partial sequences of two mitochondrial genes, 16S rRNA and CO1 (Cytochrome C oxidase subunit I) in populations of Scylla spp. obtained from eleven locations along the Indian coast were used to differentiate and resolve taxonomical ambiguity of the mud crab species in India. The sequences were compared with previously published sequences of Scylla spp. Both trees generated based on 16S rRNA and CO1 indicated that all S. tranquebarica morphotypes obtained during this study and S. tranquebarica sequences submitted previously from Indian waters reciprocally monophyletic with reference sequence of S. serrata. Both sequence data and morphological characters revealed that the species S. serrata (Forskal) is the most abundant followed by S. olivacea. Further, the 16S rRNA and COI haplotypes of Indian S. tranquebarica obtained in the study significantly differed with the known S. tranquebarica by 6.7% and 10.6% respectively whereas it differed with known S. serrata by 0.0–0.7% only, a difference that was not statistically significant. From these studies it is clear that ‘‘S. tranquebarica’’ commonly reported from India should be S. serrata (Forskal)

Fishery, biology and dynamics of dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) exploited from Indian seas

Dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) (Fig. 1) is a pelagic tuna preferring waters of temperature between 21 and 26 oC. It is one of the principal species exploited by hook and line (recreational as well as commercial fishery) operated in the oceanic region. Meat of dogtooth tuna is white and so it has great demand and fetch high price (IUCN, 2011). However, occasional ciguatera fish poisoning in humans has been reported on consumption of dogtooth tuna. It is exported in fresh and frozen state and is used for the production of sashimi, canned tuna, and pouch products. Most of the world landings of dogtooth tuna during 1963 -2006 was from the Indian Ocean. Small scale tuna long lines for the species operating in the Indian Ocean belong to Taiwan, Srilanka, Maldives, Japan or Pakista

Morphometric characteristics of the pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) caught off Cochin, southwest coast of India

The morphometric characteristics of the pelagic stingray Pteroplatytrygon violacea (Bonaparte, 1832) are described for the first time from the Indian waters. The specimen was collected at Cochin in August, 2008. The mature male specimen measured 102 cm in total length, 47 cm in disc width, 35 cm in disc length and weighed 2.5 kg. The morphometric characteristics of the specimen were very similar to that described from the North Sea

Assessment of the fishery and stock of striped bonito, Sarda orientalis (Temminck and Schlegel, 1844) along Kerala coast with a general description of its fishery from Indian coast

The striped bonito Sarda orientalis (Temminck and Schlegel, 1844) has a wide distribution in the Indo- Pacific region from east coast of Africa to the west coast of America (Jones, 1960). It grows to a length of over half a metre and does not form a regular fishery of any appreciable magnitude anywhere

Resurrection and Re-description of Pampus candidus (Cuvier), Silver Pomfret from the Northern Indian Ocean

Pomfrets (Genus Pampus) are commercially important fish in the Indo-Pacific region. The systematics of this genus is complicated because of morphological similarities between species. The silver pomfret from Indian waters has long been considered to be Pampus argenteus. Morphological and molecular examination of specimens from the Arabian Sea and Bay of Bengal regions suggested the silver pomfret from the region represents two species that are distinct both from each other and from P. argenteus from the South China Sea. Based on detailed morphological, meristic and molecular examinations, the most common species from the Indian Ocean was found to correspond with the descriptions of Stromateus candidus (Cuvier), which is resurrected from the synonymy of P. argenteus and redescribed here as Pampus candidus (new combination). The second species, which has restricted distribution in Indian waters needs further studies to arrive at taxonomic conclusions and is hence not described in the current study. Lectotypes are also designated for Pampus candidus

Fishery, biology and population characteristics of longtail tuna, Thunnus tonggol (Bleeker, 1851) caught along the Indian coast

The longtail tuna, Thunnus tonggol, Bleeker, 1851 is an economically important species from commercial and recreational point of view. The species inhabit shelf and oceanic waters of tropical and temperate regions of the Indo-Pacific between 47° N and 33° S (Froese and Pauly, 2009) and generally occupy neritic areas of the oceans close to land masses (Yesaki, 1994)