2,204 research outputs found
N-[(E)-Quinoxalin-2-ylmethylidene]-1H-indazol-5-amine
In the title molecule, C16H11N5, the mean planes of the quinoxaline and indazole fragments form a dihedral angle of 10.62 (5)°. In the crystal, weak intermolecular N—H⋯N hydrogen bonds link the molecules into zigzag chains extending in the [001] direction. The crystal packing also exhibits π–π interactions [centroid–centroid distances of 3.7080 (2) and 3.8220 (5) Å], which form stacks of the molecules parallel to the a axis
(Z)-2-Amino-3-[(E)-benzylideneamino]but-2-enedinitrile
The asymmetric unit of the title compound, C11H8N4, contains two independent molecules. In the crystal structure, intermolecular N—H⋯N hydrogen bonds link molecules into ribbons extended in the [100] direction
Diurnal variations in the vertical distribution and abundance of zooplankton in the continental shelf waters off Cochin during April 1991
The present study is based on zooplankton samples collected by vertical hauls
from 0-30, 30-60 and 60-90 m depths from a 100 m depth station in the continental
shelf (09° 44' N, 75° 42*8) off Cochin for two days at three hourly interval. The mean
displacement volume of zooplankton biomass at these depth zones were 6.24, 6.70
and 6.07 ml/100 m water while their numerical counts were 14490,13355 and 11290
no/100 m respectively. The overall mean volume (ml) and number per 100 m in the
endre water column (0-90 m) were 6.34 and 13045 respectively and were distributed
as 5.89 ml and 11715 no/100 m^ in the daytime and 6.79 ml and 14376 no/100 m^
during night hours respectively. The biomass was dominated by copepods (75.6%),
decapod larvae (12.2%), chaetognaths (6.5%) and appendicularians (2.4%) in April.
In general, copepods, decapod larvae and appendicularians showed increasing trend
in number from the bottom (60-90 m) to the surface layer (0-30 m); chaetognaths,
medusae, pteropods, heteropods, salps and doliolids were distributed more in the
middle zone (30-60 m); while ostracods and planktonic polychaetes were more in the
bottom zone (60-90 m). Distribution of amphipods and ostracods indicated significant
diurnal vertical migration. The phenomenon of mid- night sinking was noticed
in the case of copepods, chaetognaths, appendicularians, medusae, siphonophores,
salps and doliolids
Culture of live feed organisms
In any maricuUure practice, availability of seed is one of the
prime requisites for sustaining growth, development and to make
the activity viable ecologically and economically. As the natural
source of seed is often beset with environmental / conservational
problems, the dependable source is production through hatchery
techniques. Uninterrupted production and supply of live feeds alone
can sustain hatchery operations and to feed the emerging larvae or
post larvae with different feed requirements at different stages of
development / growth. Technologies developed by CMFRl in this
line are given in this paper. The method of culturing important live
feed organisms such as micro-algae, rotifers, cladocerans and
Artemia salina along with their harvesting and preservation are
briefly described in this accoun
Fishery for cephalopods using Fish Aggregating Device off Blangad in Kerala
Fish Aggregating Device (FAD) is being deployed off Blangad a small coastal village in Chavakkad, Thrissur district of Kerala, for catching squids and cuttlefishes. The FADs are made up of coconut spadix (locally known as Kolanjil), plastic bottles, nylon ropes, pieces of fishing nets and sacks containing large quantities of sand. This structure is locally known as Norumbu and fishermen from Colachel and Kanyakumari are mainly involved with this activity. The coconut spadix tied with nylon ropes and plastic bottles as float have sacks filled with sand as anchors (Figs. 1 & 2). This structure errected in the sea in identified sites at a distance of 20-44 km from shore and having 30-50 fathom depth, acts as an aggregating device, especially for cephalopods. The fishers record its position on their Global Position System (GPS) unit and after 5 days arrive to operate hooks & lines (Fig.3). Fishing season is from October-May and during the peak season, around 200 fibre boats are operating from Blangad. Most of the boats are fitted with 2 numbers of 9 hp outboard engines. A tractor is used for hauling the boat to the beac
Childhood cancer in the south Asian population of England (1990–1992)
Cancer incidence in 1990–92 among English south Asian (residents with ethnic origins in India, Pakistan or Bangladesh) and non-south Asian children is compared. Standardized incidence ratios show significant overall excesses in south Asians (131), largely due to higher rates in south Asian boys, and specific excesses for leukaemia (141), lymphoid leukaemia (141), lymphoma (172) and hepatic tumours (375). Aetiological investigation is required. © 2001 Cancer Research Campaign http://www.bjcancer.co
CMFRI Marine Fisheries Policy Series No.15; Fishery Management Plan for Palk Bay Blue Swimming Crab
Crabs are widely distributed in Indian seas and form minor fishery at various
regions along the east and west coasts. Crabs contribute a share of 11.1 % in total
crustacean landings, with an approximate production of 53476 tonnes in 2017.
Three portunid crabs, Portunus pelagicus, Portunus sanguinolentus and Charybdis
feriatus form the majority of the regular crab landings in India.
The demand for Portunus pelagicus, commonly known as Blue Swimming Crab
(BSC) is consistently increasing ever since its export started in the beginning of the
century. The State of Tamil Nadu is leading in marine crab landings particularly for
the blue swimming crab production in India. The major landing centres for BSC are
located in the Palk Bay (PB) and Gulf of Mannar (GoM) areas of Ramanathapuram,
Pudukkottai and Thanjavur districts of the state. BSC products form the most
important internationally traded commodity from the region and contribute
significantly to the livelihood of crab merchants and crab fishers of the area. The
Central Marine Fisheries Research Institute has been monitoring the BSC fishery
and studying the biology the species along with other marine resources. During
the last decade of the 20th century more focused and in-depth studies have been
conducted on Portunus pelagicus and established the fact that apart from its
fisheries importance, BSC is also a suitable candidate species for farming.
This document gives insights on BSC fishing zones, major fishing craft and gears, area
wise and centre wise production details, trade, processing industry and export markets.
Furthermore, it elucidates the complete life cycle of the species including its growth and
reproductive biology as these form essential and integral inputs while formulating the
management decisions. As BSC is a highly valuable commodity it necessitates urgent
attention to its responsible exploitation and action plan for the judicious management
of the resource to accomplish BSC as a sustained fishery. Conclusions have drawn
based on the facts and evidences, acquired from exhaustive field and laboratory studies
and guidance on a Fishery Management Plan for Palk Bay BSC fishery are presented
Bayesian State-space Implementation of Schaefer Production Model for Assessment of Stock Status for Multi-gear Fishery
Knowing the status of marine fish stock is of utmost importance to develop management strategies for sustainable harvest of marine fishery resources.
A widely accepted approach towards this is to derive sustainable harvest levels using time series data on fish catch and fishing effort based on fish
stock assessment models like Schaefer’s model that describe the biomass dynamics. In India, the marine fishery is of complex multi-species nature
where in different species are caught by a number of fishing gears and each gear harvests a number of species making it difficult to obtain the fishing
effort corresponding to each fish species. Since the capacity of the gears varies, the effort made to catch a resource cannot be considered as the sum
of efforts expended by different fishing gears. Hence, it demands the importance of effort standardisation for making use in stock assessment models.
This paper describes a methodology for the standardization of fishing efforts and assessing fish stock status using Bayesian state-space implementation
of the Schaefer production model (BSM). A Monte Carlo based method namely Catch-Maximum Sustainable Yield (CMSY), has also been used for
estimating fisheries reference points from landings and a proxy for biomass using resilience of the species. The procedure has been illustrated with
data on Indian mackerel (Rastrelliger Kanagurta) collected from the coastal state of Andhra Pradesh, India during 1997-2018. Maximum Sustainable
Yield (MSY) of Indian mackerel for Andhra Pradesh has been estimated. A comparison between both CMSY and BSM methods have been made and
found that the estimates are in close agreements
विशेष स्थानिकता और समुद्री जीव जतीयों की संपन्नता के प्रसंग में मान्नार खाडी आवास व्यवस्था की जैवविविधता
कृपया पूरा लेखा पढ
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