243 research outputs found
Oil Spill Occurrences along Indian Exclusive Economic Zone
Oil Spill Occurrences along Indian Exclusive Economic Zon
Reproductive biology, diet and feeding pattern of longtail tuna Thunnus tonggol (Bleeker, 1851) in the north-eastern Arabian Sea off Gujarat, India
Longtail tuna Thunnus tonggol (Bleeker, 1851) is the major tuna resource in the neritic realms of the northern Arabian Sea and forms considerable fishery in the coastal nations in the region. Gujarat, on the north-west coast is the major province landing longtail tuna in India. The paper attempts to add to the hitherto sparse knowledge base on biology of the longtail tuna fished along the north-west coast of India, through a study spanning from 2011 to 2015. Reproductive biology, spawning, food and feeding dynamisms of the species were investigated. Sex ratio of the species was estimated as 1:2.1 and depicted an increase in male preponderance as the size increased. The fish attains maturity at 607 mm and it spawns during summer months starting from May. The fish is typically a non-selective feeder and over 22 taxa comprising of fishes, cephalopods and crustaceans formed the diet at varying rates over the year. Variation in feeding intensity at different reproductive stages is discussed besides the constraint posed by the large presence of unidentifiable, partially digested gut content
Taxonomic note on the Indian species of genus Netuma
In Indian waters, genus Netuma is represented by two
species namely N. bilineata and N. thalassina (Order:
Siluriformes, Family: Ariidae). Rounded shout, thin lips,
inconspicuous median longitudinal groove, and higher
anal fin ray count (16-19) are characters of N. bilineata
while N. thalassina has conical snout, clearly visible median
longitudinal groove and lower anal fin ray count (13-15).
Prior to the erection of N. bilineata (earlier considered as
synonym of N. thalassina) as valid species, Indian workers
had difference of opinion regarding the representation
of species under this genus from Indian waters
Stranding of whale shark off Madhavpur, Gujarat
A dead male whale shark (Rhincodon typus) was
found off Madhavpur coast, near the fish landing
centre on morning of 28th September, 2017. The
investigations were covered at the joint team of
ICAR-CMFRI and Wildlife Trust of India (WTI),
Veraval, Gujarat. The carcass showed an injury
below the first dorsal fin but cause of its death could
not be ascertained. Some measurements of the
stranded whale shark were recorded before it was
burie
Diet composition and feeding dynamics of Trichiurus lepturus Linnaeus, 1758 off Gujarat, north-west coast of India
The largehead ribbonfish, Trichiurus lepturus Linnaeus, 1758 forms a major fishery along north-west coast of India comprising the two coastal states of Gujarat and Maharashtra. Diet composition was analysed for five years (2010-2014) to understand shifts if any in the prey items. Seasonal changes in the prey items were studied for three years (2012-2014) to explore the temporal dynamics of prey availability in the ecosystem and in largehead ribbonfish guts. Feeding indices viz., Stomach fullness index (SFI), empty stomach ratio (ESR), gastrosomatic index (GaSI) and relative gut length (RLG) explained the feeding behaviour, seasonal dynamics and ontogenetic shifts in prey items. The Vacuity Index (VI) was estimated as 37.56%, indicating that T. lepturus is a carnivore and relatively edacious. Diet of T. lepturus comprised of fishes (47.16%), crustaceans (45.22%), molluscs (4.33%) and miscellaneous items (3.28%). Acetes sp. was the most dominant prey item during the study period. Feeding intensity was found to be high during the post-monsoon months which coincided with the period of gonadal maturation of the fish. Significant variations (p<0.05) were seen in the feeding indices during different months, different sizes and between sexes due to the availability of prey items, physiological changes and ontogenetic shifts. A detailed knowledge on diet composition, temporal dynamics in diet patterns and feeding indices can reveal the trophic interaction of prey-predator, resource abundance and fluctuations which are important inputs in
ecology-based fishery management models/tools
Non-target species interactions in tuna fisheries and its implications in fisheries management: Case of large-mesh gillnet fisheries along the north-west coast of India
Occurrence of non-target, associated and dependent species is a feature
of tuna gillnet fisheries world-over, posing a great concern for fisheries
management. Predominance of small-scale or artisanal fisheries in the
region compounds the concern due to the uncertainty in data. There is
dearth of information on the catches and the non-target species
interaction in the tuna gillnets fisheries in India, especially from the
north-west coast, where gillnet is the predominant gear targeting the
tuna. We collected spatially explicit catch data with voluntary participation
of fishermen from Veraval, Gujarat and quantified the species wise
catches over space and time for 567 fishing operations spread across six
years (2011-2016). Species composition, seasonal variation, nature and
level of interrelationship in catch incidences, similarities among different
groups of resources etc. were ascertained using various statistical tests
like the Kruskal-Wallis rank test, PearsonтАЩs correlation and principal
component analysis (PCA). The study reveals spatial expanse of gillnet
fisheries of Gujarat and their major fishing grounds together with
variations in catches of different groups over space and time. Nature and
strength of interaction of sensitive species like turtles and dolphins as
well as the unicorn leatherjacket, an emerging catch in the gillnet tuna
fisheries was ascertained and GIS maps depicting the areas of copious
presence of these groups are presented. Management implications of
such interactions as well as the potential of involving fishermen to
gather spatially explicit fishery data, paving way for their active
Available online at: www.mbai.org.in doi: 10.6024/jmbai.2018.60.1.2047-03
involvement in fisheries governance are discussed. The study can be
replicated at national level to enhance the understanding on the gillnet
fisheries to bring in pragmatic interventions to sustain the fisheries
Effects of Renal Denervation on Insulin Sensitivity and Inflammatory Markers in Nondiabetic Patients with Treatment-Resistant Hypertension
Increased sympathetic activity is important in the pathogenesis of hypertension and insulin resistance. Afferent signaling from the kidneys elevates the central sympathetic drive. We investigated the effect of catheter-based renal sympathetic denervation (RDN) on glucose metabolism, inflammatory markers, and blood pressure in nondiabetic patients with treatment-resistant hypertension. Eight subjects were included in an open-labelled study. Each patient was studied before and 6 months after RDN. Endogenous glucose production was assessed by a 3-3H glucose tracer, insulin sensitivity was examined by hyperinsulinemic euglycemic clamp, hormones and inflammatory markers were analyzed, and blood pressure was measured by office blood pressure readings and 24-hour ambulatory blood pressure monitoring. Insulin sensitivity (M-value) increased nonsignificantly from 2.68тАЙ┬▒тАЙ0.28 to 3.07тАЙ┬▒тАЙ0.41 (p=0.12). A significant inverse correlation between the increase in M-value and BMI 6 months after RDN (p=0.03) was found, suggesting beneficial effects on leaner subjects. Blood pressure decreased significantly, but there were no changes in hormones, inflammatory markers, or endogenous glucose production. Our results indicate that RDN may improve insulin sensitivity in some patients with treatment-resistant hypertension, albeit confirmation of these indications of beneficial effects on leaner subjects awaits the outcome of larger randomized controlled studies
New Geographical Record for Muraenid Eels (Anguilliformes: Muraenidae) along the Northeast Arabian Sea, Western Indian Ocean
Fishes of family Muraenidae, popularly known as moray eels, are one of the most diverse groups among true eels. Gymnothorax is the most predominant genus in terms of diversity along Indian coastline (31 species including recent description and distributional records), but they rarely form the fishery of commercial importance. Gymnothorax dorsalis, species of elongated unpatterned moray eels characterized by eight to nine pre-dorsal vertebrae, three infraorbital pores and low dorsal and anal fin united with caudal fins is reported for the first time from the west coast of India. Gymnothorax reticularis, reticulated patterned eel with 18тАУ19 vertical dark bars, five pre-dorsal vertebrae and 10тАУ11 vomerine teeth is also reported for the first time from the northwest coast of India
Symmetry of the remanent state flux distribution in superconducting thin strips: Probing the critical state
The critical-state in a thin strip of YBaCuO is studied by magneto-optical
imaging. The distribution of magnetic flux density is shown to have a specific
symmetry in the remanent state after a large applied field. The symmetry was
predicted [PRL 82, 2947 (1999)] for any Jc(B), and is therefore suggested as a
simple tool to verify the applicability of the critical-state model. At large
temperatures we find deviations from this symmetry, which demonstrates
departure from the critical-state behavior. The observed deviations can be
attributed to an explicit coordinate dependence of since both a surface
barrier, and flux creep would break the symmetry in a different way.Comment: 5 pages including 5 eps figures, submitted to PR
Dead Bryde's whale washed ashore at Veraval, Gujarat
BrydeтАЩs Whale (Balaenoptera edeni Anderson,
1879) measuring 10.4 m in length and weighing
about 7 tons was found washed ashore on the beach
of Veraval on 4th august 2017. Locally called as
тАЬMachchhтАЭ it was found in dead condition with small
injuries in the caudal peduncle and genital region.
With the intervention and supervision of forest
officials, it was towed ashore and a veterinary
officer conducted post-mortem after which it was
buried on the shore. Occurrenc
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