Nandakumar, G; Dr.Damodaran,R(Cochin University of Science and Technology, 1997)
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Abstract:
Crustaceans comprising numerous edible species of prawns, lobsters and crabs inhabiting different ecosystem form significant portion of the aquatic food resources of the world. Among the crustaceans, prawns are the most commercially exploited group and hold premier rank by virtue of their importance as an esteemed food of gourmet and on account of their high export value. Met-ape-naeus manoceras (Fabricius, 1798) which is known IS,Speckled shrimp’ (FAD name) and ‘Brown shrimp’ ( common nameused in the industry) is one of the commercially important marine penaeid prawns of India. During 1995, M. monaceros catch constituted 7.5 Z of the all India marine penaeid prawn landings. M. monoceros attains a maximum length of about 200 mm and has high export potential.Thus realising the growing importance of M. monoceros in the capture fisheries, it was felt, that it would be ideal to carry out detailed study on this species for rational exploitation and management of its fishery. Hence, the present work entitled, “Biology, population characteristics and fishery of the speckled shrimp Hetapenaeus monoceros (Fabricius, 1798) along Kerala coast“ was undertaken by the author. The thesis is laid out in seven chapters comprising TAXONOMY, FOOD AND FEEDING HABITS, AGE AND GROWTH, REPRODUCTION,LENGTH-WEIGHT RELATIONSHIP, FISHERY and POPULATION DYNAMICS
Description:
Division of Marine Biology, Microbiology and Biochemistry,
School of Marine Sciences, Cochin University of Science and Technology
Manju, M.N; Dr. N. Chandramohanakumar(Cochin University of Science and Technology, April 6, 2015)
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Abstract:
Mangroves are diverse group of trees, palms, shrubs, and ferns that share a
common ability to live in waterlogged saline soils exposed to regular flooding, and are
highly specialised plants which have developed unusual adaptations to the unique
environmental conditions. They are sites of accumulation and preservation of both
allochthonous and autochthonous organic matter owing to their strategic loction at
the interface between land and sea and prevailing reducing environment. They are
among the most productive ecosystems and are efficient carbon sinks with most of the
carbon stored in sediments.Mangrove ecosystems play a significant role in global
carbon cycle and hence the knowledge on the processes controlling the delivery of
organic matter to coastal sediments, and how these signatures are preserved in the
sediment is a prerequisite for the understanding of biogeochemical cycles.
The evaluation of nature and sources of organic matter can be accomplished by
the determination of biochemical constituents like carbohydrates, proteins and lipids.
When characterised at molecular level, lipids provide valuable information about the
sources of organic matter, even though they account only small fraction of organic
matter. They are useful for the paleo-environmental reconstruction because of their low
reactivity, high preservation potential and high source specificity relative to other
organic class of compounds. The application of recent analytical techniques has
produced a wealth of useful information but has also indicated the gaps in our
knowledge on cycling of organic matter in the coastal ecosystems. The quantity and
quality of organic matter preserved in sediments vary depending up on the nature of
material delivered to the sediment and on the depositional environment. The input from
both autochthonous and allochthonous sources sharpens the complexity of
biogeochemistry of mangrove ecosystem and hence bulk sedimentary parameters are not completely successful in evaluating the sources of organic matter in mangrove
sediments. An effective tool for the source characterisation of organic matter in coastal
ecosystems is biomarker approach. Biomarkers are chemical "signatures" present in
environmental samples whose structural information can be linked to its biological
precursor. The usefulness of molecular biomarkers depends on high taxonomic
specificity, potential for preservation, recalcitrant against geochemical changes, easily
analysable in environmental samples and should have a limited number of well-defined
sources.
Sunesh, Thampy; Dr.Ramachandran,A(Cochin University of Science And Technology, July , 2009)
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Abstract:
Garra surendranathanii is a hill stream cyprinid endemic to Kerala.
According to IUCN based classification, G. surendranathanii is grouped under
the threatened category. This endemic fish is having highly restricted and
fragmented distribution and reported only from 5 river systems viz. Chalakudy,
Periyar, Pamba, Achenkoil and Bharathapuzha. Categorization of this fish as a
potential ornamental candidate can invariably add more pressure on the threat
status of this particular species. Hence, this species is considered as one which
requires foremost attention for conservation. Hitherto, no infomiation is
available on the bionomics, resource characteristics and any conservation
attempts of G. surendranathanii. Studies on detailed life history traits and
development of captive breeding technique are indispensable for successful
fishery management.The present study was undertaken with the following obj ectives:
To study the Length-weight relationship and condition factor to
ascertain the relationship between length and weight and general
wellbeing ofthe fish To study the age and growth to understand the age composition of the
exploited stock, age at first maturation and life span of the species. To study the reproductive biology of G. surendranathanii to gain insights in the process of gametogenesis, spawning, sex ratio, fecundity and other related aspects which are essential for developing captive
breeding technology of this species. To develop captive breeding technology and cryopreservation ofgametes of G. surendranathanii for conservation
Description:
School of marine sciences, department of industrial fisheries, Cochin University of Science And Technology
Euphrasia, C J; Dr.Madhusoodana,Kurup B(Cochin University Of Science And Technology, July 30, 2004)
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Abstract:
The previous faunistic studies were concentrated.on the taxonomical and zoogeo—
graphical aspects. These studies contributed to many new additions to
the fish fauna of Kerala meanwhile many species described earlier are
reported missing in recent years. Many fish species were collected only
once or twice by scientists. Detailed information on distribution, habitat,
feeding habits, reproduction, population size, etc. are available only with
regard to a very few fish species. A meaningful assessment on the
biodiversity status of the majority of freshwater fishes cannot be done for
want of sufficient data base and therefore, no suitable conservation and
management programmes are forthcoming for the protection and
preservation of the unique fish germplasm resources of Kerala. The
present study was conceptualised and undertaken mostly aiming at
bridging these gaps by generating an authentic data base on the
distribution, resource characteristics and bionomics of the threatened
fishes inhabiting the rivers of Kerala. Osteobrama bakeri (Day) is an endemic fish having a very highly restricted and fragmented distribution in Periyar, Chalakudy, Kabini,
Kallada and Meenachil rivers of Kerala. This belongs to vulnerable
category and is locally known as Mullanpaval which is valued as food
fish. Besides, due to its vibrant and attractive colouration and easiness
for domestication, it has great potential for being propagated as an
ornamental fish. Hitherto, no information is available on the bionomics
and resource characteristics of this species. Studies on detailed life
history traits are indispensable for fishery management, development of
captive breeding technique and implementation of various conservation
programmes. In the present study, a pioneer attempt is also made to
investigate the life history traits, resource characteristics, proximate
composition, etc. of O.baken'.
Description:
School of Industrial Fisheries
Cochin University of Science and Technology
Nimbalkar, V D; Dr.Alagaraja, K(Cochin University of Science And Technology, August , 1991)
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Abstract:
Fish, a natural resource, has received great attention
from all over the world. since it provides a cheap protein,
employment and income to the millions of people for centuries.
So fishermen, industrialist and multinationals are trying to
exploit the marine resources to their maximum benefit by
using modern craft, advance fishing equipments and efficient
gear. Fishery resources in the open system particularly in
oceans, were considered to be unlimited. However, recent
developments in the innovation of efficient craft and gear
using well tested material fitted with modern equipments that
have greatly enhanced the mobility of craft, agility of gear
and the ability of equipments to locate fishery resources
have proved otherwise. Hence as the exploitation increases
with more effort entering the fishery, the catch per unit
of fishing effort starts to decline due to the limitness
of the resources. The heavy fishing pressure in the recent
past led to commercial extinction of a number of stocks such
as. the North Sea herring, California sardine, Japanese
Sardine and Peruvian anchovy (FAO. 1968: Gulland, 1974).
In India, seer fish from Palk-Bay declined due to uncontrolled
fishing (Devaraj 1983).
Lakshmi Devi, P; Anekutty, Joseph(Cochin University Of Science And Technology, February 24, 2015)
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Abstract:
Among the decapod crustaceans, brachyuran crabs or the true crabs occupy a very significant position due to their ecological and economic value. Crabs support a sustenance fishery in India, even though their present status is not comparable to that of shrimps and lobsters. They are of great demand in the domestic market as well as in the foreign markets. In addition to this, brachyuran crabs are of great ecological importance. They form the conspicuous members of the mangrove ecosystems and play a significant role in detritus formation, nutrient recycling and dynamics of the ecosystem. Considering all these factors, crabs are often considered to be the keystone species of the mangrove ecosystem. Though several works have been undertaken on brachyuran crabs world –wide as well as within the country, reports on the brachyuran crabs of Kerala waters are very scanty. Most of the studies done on brachyuran fauna were from the east coast of India and a very few works from the west coast.
Among the edible crabs, mud crabs belonging to genus Scylla forms the most important due to their large size and taste. They are being exported on a large scale to the foreign markets like Singapore, Malaysia and Hong Kong. Kerala is the biggest supplier of live mud crabs and Chennai is the major centre of live mud crab export. However, there exists considerable confusion regarding the identification of mud crabs because of the subtle morphological differences between the species.In this context, an extensive study was undertaken on the brachyuran fauna of Cochin Backwaters, Kerala, India, to have a basic knowledge on their diversity, habitat preference and systematics. The study provides an attempt to resolve the confusion pertaining in the species identification of mud crabs belonging to Genus Scylla.
Diversity study revealed the occurrence of 23 species of brachyuran crabs belonging to 16 genera and 8 families in the study area Cochin Backwaters. Among the families, the highest number of species was recorded from Family Portunidae .Among the 23 crab species enlisted from the Cochin backwaters, 5 species are of commercial importance and contribute a major share to the crustacean fishery of the Cochin region. It was observed that, the Cochin backwaters are invaded by certain marine migrant species during the Post monsoon and Pre monsoon periods and they are found to disappear with the onset of monsoon. The study reports the occurrence of the ‘herring bow crab’ Varuna litterata in the Cochin backwaters for the first time. Ecological studies showed that the substratum characteristics influence the occurrence, distribution and abundance of crabs in the sampling stations rather than water quality parameters. The variables which affected the crab distribution the most were Salinity, moisture content in the sediment, organic carbon and the sediment texture. Besides the water and sediment quality parameters, the most important factor influencing the distribution of crabs is the presence of mangroves. The study also revealed that most of the crabs encountered from the study area preferred a muddy substratum, with high organic carbon content and high moisture content. In the present study, an identification key is presented for the brachyuran crabs occurring along the study area the Cochin
backwaters and the associated mangrove patches, taking into account the morphological characters coupled with the structure of third maxillipeds, first pleopods of males and the shape of male abdomen. Morphological examination indicated the existence of a morphotype which is comparable with the morphological features of S. tranquebarica, the morphometric study and the molecular analyses confirmed the non existence of S. tranquebarica in the Cochin backwaters.
Johny T, Varghese; Dr.Madhusoodana,Kurup B(Cochin University of Science and Technology, April , 2007)
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Abstract:
Controlling the inorganic nitrogen by manipulating carbon /
nitrogen ratio is a method gaining importance in aquaculture
systems. Nitrogen control is induced by feeding bacteria with
carbohydrates and through the subsequent uptake of nitrogen from
the water for the synthesis of microbial proteins. The relationship
between addition of carbohydrates, reduction of ammonium and the
production of microbial protein depends on the microbial conversion
coefficient. The carbon / nitrogen ratio in the microbial biomass is
related to the carbon contents of the added material. The addition of
carbonaceous substrate was found to reduce inorganic nitrogen in
shrimp culture ponds and the resultant microbial proteins are taken
up by shrimps. Thus, part of the feed protein is replaced and feeding
costs are reduced in culture systems.The use of various locally available substrates for periphyton
based aquaculture practices increases production and profitability .However, these techniques for extensive shrimp farming have not so far been
evaluated. Moreover, an evaluation of artificial substrates together
with carbohydrate source based farming system in reducing inorganic
nitrogen production in culture systems has not yet been carried-out.
Furthermore, variations in water and soil quality, periphyton
production and shrimp production of the whole system have also not
been determined so-far.This thesis starts with a general introduction ,
a brief review of the most relevant literature, results of various
experiments and concludes with a summary (Chapter — 9). The
chapters are organised conforming to the objectives of the present
study. The major objectives of this thesis are, to improve the
sustainability of shrimp farming by carbohydrate addition and
periphyton substrate based shrimp production and to improve the
nutrient utilisation in aquaculture systems.
Description:
School of
Industrial Fisheries, Cochin University of Science and Technology
Nisha, P C; Dr. George, K C(Central Marine Fisheries Research Institute, October , 2006)
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Abstract:
The present investigation revealed three types of circulating haemocytes
in the haemolymph of F. indicus: hyalinocytes, small-granule haemocytes, and
large-granule haemocytes. Intermediate stages indicate the maturing process of a
single cell. The presence of enzymes such as peroxidase, phenoloxidase and acid
phosphatase in the haemocytes, and the substantial production of oxygen radicals
during phagocytosis show that the haemocytes are capable of mounting a fme
cellular defense mechanism. The enzyme activities of the serum and the presence
of agglutinins in the serum, which may act as opsonins, agglutinate foreign
particles and augment phagocytosis, confirm the presence of a superior humoral
immune system in F. indicus.Bacterial infection caused considerable variations in the cellular and
humoral factors, such as the number of circulating cells and haemagglutinating
activity, especially in the initial hours of infection. The total haemocyte count,
haemagglutination titer and phenoloxidase enzyme showed significant reductions
on bacterial presence and could be used as indicators of bacterial infection.The number of circulating cells showed drastic fluctuation on exposure to
pollutants. Nuvan at low concentrations was able to produce changes in the
haemolymph factors and in the tissue organization, which implies that the animal
is under stress and is easily prone to infections. Exposure to nuvan resulted in
significant variation in all of the cellular and humoral factors, especially, the total
haemocyte count, percentage of small granule haemocytes, phagocytic activity
and the haemagglutinating activity, which might be good indicators of pesticide
pollution. Heavy metal exposure caused significant increase in total haemocyte
count and reduction in phenoloxidase enzyme activity Even changes in the
physio-chemical parameters, such as salinity caused fluctuations in the defense
factors, indicating stress in this euryhaline species. The dietary incorporation of a
commercial immunostimulant containing P-l,3 glucan resulted in stimulation of
some of the humoral defense factors of F indicus, but was time dependent. The
modulations, on exposure to various external factors, in the cellular and humoral
factors, especially, total haemocyte count, phagocytic activity, haemagglutinating
activity and the phenoloxidase and acid phosphatase enzymes suggest that these
parameters could be used as indicators of the health status of F indicus, which
assist in better monitoring and effective health management of this important
cultured species.
Zeena, Ravi P; Dr.Chandramohanakumar, N(Cochin University of Science & Technology, May , 2005)
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Abstract:
Mangrove swamps are unique inter-tidal wetland ecosystems found in sheltered tropical and subtropical shores.Mangrove sediments can be considered as large reservoirs of amino acids,which exist in several different forms,like free amino acids in the sediment micropores,as amino acids,peptides or proteins bound to clay minerals or as amino acids,peptides or proteins bound to humic colloids.Inorder to assess survival conditions of organisms of mangroves,it is important to understand stability of amino acids in the sediments.The amounts of amino acids present in sediment represent a balance between its synthesis and destruction by microorganisms.Thus amino acid analysis offers more insight into the processes of diagenesis,which changes the nature and characteristics of organic matter deposition and decomposition.
Description:
Department of Chemical
Oceanography Cochin University of Science
and Technology
Abhilash P. Kailas; Dr. S. Muraleedharan Nair(Cochin University of Science and Technology, October 5, 2015)
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Abstract:
Sea is a huge source to meet our daily needs, lifff(rrsccaaaeyohdpnnmmmimlruCeeeaorcxnefkuuouiaosaae nedparihtnatvesmtrpdmerrdnosi cwrlurlstdo -ofaieasopautiktlaeotnc intcyie,rcensruact irnshtoreitotee nnioipiaeetsnmma oeins oSsdiipdoonu soienadh hnoaae nno ein hctlshlacscnalersadiy i, udif ,y t sec aag bae wo sosc fr eoc a ntsralnoi alfador,oeahtefxneeofl nuc otu h nu imnatofe ratata ncisted rn teoieesdvdxrnnhescceexptsp gmn )ieis oadhitratmtnit dapo imoo i soheiwurc a s- toaaorhpstiie aieaidsr,nrneaedttiod ldenahi s. nctyiitdsl nictsseueavev sSera em d,h,e cdu sbsaeer depsraowe nde ,,cpscn m eaa n hrnfx uiesia tvoitsb memdoytprveatoati ft aisrvfrohceertfr dettogcenitt eo oi euafarsn sgepua srre nwctsamucrmaneoeeuurnworaieostnael aelaut anrtcstptai.iavmula,di sdenetzt et,a rcpn aeHbioetr ren s cttapniwrsibiyredl(nhhar,ciutnele eott Pd yssi naae.aos tgntbfspac uo,h shaalloi tt te eitlisr Tm,nu(eietaa teo s v x-o atvhutotrhdrreb, hqedtdhepy hdloa,fcsevetoesl gguynio uioehueeerlrea rv bpaaepsarti er b acprcepiaiei,chtmanoet rt ttoiilaerovt ahiscyd,tri tft os inktannao oi1nm iitieoccsiirttmdftre,etogcv t0etn.u aino ie pnye seohtmi e aom0oraosad hes lsspa cebnr.nm0end awsae a iiasem)hi vxyn0,ot.iliwPo p o neeingeireb s fTet-chhncaf ttbri el sh,ei tnh chy hbyyonbsaaepivmae .eoa eeeeitlbll,lfdmabern ooos eotltmlayaaiealsccoo,e r ncbtc uw iranuo)dim.aoisgnhlwahp iesn eciysf ot,aeitprOete hes amsecsdh( hfeerdemrh.m.sRiy lfad a i ees dgaosi caeycclag vh T ii illhtasfcTthcuflorccsyloeh aoiol horsot tae shn,csa r.rai erhdrtoa menea,lyxnlesdeh ayrs sao r dcctadi gN e epigep,m etrtapat nn a uy,a reraie oywcrd rahb vireai enepmseacwoanuspnvyyeirepso ntcocrerttassepc c iieeaedohefoaeab me-tnc rie l ndsuhnmaemng i wioi,scgaos tclcaeltnteoeesomaiga eeluaic eieytn, yci ivucnnspi) a.atet.dtfsf,ops g a,is iodgawltbf d hsou,oIenosrwoee a grgino sensoc entoauddrgmeforf h lieureaw o as minaeo nntatb itd t lnuohrhecndieaaratttotoaicssdhndphooyeeaecsssssrffl