Studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab Scylla serrata (Forskal)

This thesis Entitled studies on the effect of toxic heavy metal mercury on the physiology and biochemistry of an estuarine crab scylla serrata (Forskal). Evaluate the toxicity of three sub lethal concentrations of mercury, viz., 0.009 mg/l, 0.02 mg/1, and 0.04 mg/l on the mud crab, Scylla serrata through bioaccumulation, and depuration studies. To characterize the biochemical responses to the sub-lethal stress of mercury in chelate muscles, abdominal muscles, hepatopancreas and gills. To study the activity pattern of acid and alkaline phosphatases in mercury-exposed crabs. To evaluate the induced changes in these tissues through histopathological studies,The Cochin backwaters is one of the most productive and biologically active backwater systems, and is the habitat of varieties of fishes, mollusks, and crustaceans, though this water body also receives tons of effluents from factories located on the banks of the river, Periyar.To study the activity levels of acid and alkaline phosphatases in crabs, at three time periods, exposed to three sub lethal concentration of mercury,

‘Studies on the fishery and culture prospects of mud crabs (Genus Scylla de Haan) along the Kerala coast

Kerala has been one of the leading maritime states in India for the exploitation and export of mud crabs (Raj, 1992). Many brackishwater systems like the Ashtamudi lake, Vembanad lake, Cochin backwaters and Korapuzha estuary are well known for their rich population of mud crabs. Realizing the imperative need to build up a strong scientific base for proper management and conservation of the resource and also to develop proper technologiesfor seed production and farming of mud crabs, a detailed study was undertaken on the mud crabs of Kerala coast and the results are described in the thesis. The thesis is presented in four chapters

Two isoforms of anti-lipopolysaccharide factors identified and characterized from the hemocytes of portunid crabs, Portunus pelagicus and Scylla tranquebarica

Anti-lipopolysaccharide factors (ALFs), a type of cationic antimicrobial peptides (AMPs), and their derivatives are becoming predominant candidates for potential drugs in viral and bacterial diseases. This study reports the first ALF from the mud crab Scylla tranquebarica (StALF, JQ899453) and the second ALF isoform from the blue swimmer crab Portunus pelagicus (PpALF2, JQ899452). Both sequences encoded for precursor molecules, starting with a signal peptide containing 26 amino acid residues, followed by a highly cationic mature peptide, containing two conserved cysteine residues flanking a putative lipopolysaccharide (LPS)-binding domain. BLAST analysis revealed that both PpALF2 and StALF exhibited significant similarity with crustacean ALF sequences. The predicted molecular mass of the mature ALFs was 11.2 kDa with an estimated pI of 10.0. PpALF2 and StALF also showed the typical pattern of alternating hydrophobic and hydrophilic residues in their putative disulphide loop, suggesting that they comprise the same functional domain. Phylogenetic analysis showed that PpALF2 and StALF have similar evolutionary status and they were phylogenetically ancient immune effector molecules which may play an essential role in the host defense mechanism. The spatial structures of PpALF2 and StALF possessed four beta-strands and two alpha-helices. The results indicated that there were more than one ALF involved in crab immunity against various pathogens. ALFs would provide candidate promising therapeutic or prophylactic agents in health management and diseases control in crustacean aquaculture

Brachyuran Crabs of Cochin Backwaters- Diversity, Habitat Ecology and Systematics, with special emphasis to Genus Scylla

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.

Zwischen Scylla und Charybdis [Rezension]

j. b.

War of the rebellion; or, Scylla and Charybdis.

Mode of access: Internet.

Effects of marine reserve protection on the mud crap Scylla serrata in a sex-biased fishery in subtropical Australia

The impact of sex-biased fishing and marine reserve protection on the mud crab Scylla serrata was examined by comparing the catch rates (catch-per-unit-effort, CPUE), mean size, sex ratios and movement of crabs in 2 coastal marine reserves (1.9 and 5.7 km(2)) and 4 fished non-reserve sites in subtropical Australia. Five years after closure, both marine reserves supported higher catch rates and a larger mean size of S. serrata than non-reserve sites. Males dominated catches of S. serrata in both marine reserves, where CPUE was at least twice as high within the reserves compared to non-reserve sites. Male crabs were also 10% larger in the reserves compared to adjacent fished areas, and of the total male catch, over 70% were equal to or greater than legal size compared to less than 50% outside the reserves. The sex ratio of S. serrata was skewed towards females in all nonreserve sites, which was most likely a result of the ban on taking female S. serrata in Moreton Bay. As only male crabs of >= 15 cm CW made up the S. serrata fishery in Moreton Bay, sex ratios of mature male and female crabs were examined, revealing a strong skew (2:1) towards mature males in both marine reserves. Of the 472 S. serrata captured in this study, 338 were tagged in the reserves in order to document movement of the crabs between the reserve and non-reserve sites. Of the 37 recaptured crabs, 73% were recorded inside the reserves, with some spillover (i.e. cross-boundary movement) of crabs recorded in fished areas. This study demonstrates the effectiveness of small (< 6 km(2)) marine reserves for sex-biased exploited fisheries species.

Auctioneers and misdescription:between Scylla and Charybdis

In Elidor Investments SA v Christie's, Manson Woods Ltd the court implied a term as to Wednesbury reasonableness into an auctioneer's agency contract which fettered its ‘sole and complete discretion’ to describe lots. It is contended that, in so doing, the court unjustifiably and unnecessarily extended the jurisdiction into areas where it was not required and, in granting an injunction to restrain the sale of the lots, failed properly to apply the appropriate criteria.

Macrophage migration inhibitory factor (MIF) family in arthropods : cloning and expression analysis of two MIF and one D-dopachrome tautomerase (DDT) homologues in Mud crabs, Scylla paramamosain

5. Acknowledgements This research was supported by grants from the National Natural Science Foundation of China (Nos. 31172438 and U1205123), the Natural Science Foundation of Fujian Province (No. 2012J06008 and 201311180002) and the projects-sponsored by SRF. TW received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.

Les espèces du genre scylla a Nhatrang (Vietnam)

The species of Scylla found in Vietnam have been studied in relation to the systematic revision made by Estampador, and to establish the distinctive morphological characters of the species. The status of four forms is discussed: Scylla oceanica, Sc. tranquebarica, Sc. serrata, and Sc. serrata var. paramamosain.

The doing and undoing of global literature : myth, microcosm and atopia in triestine writing

La présente étude conduit les traditions fragmentées de la culture littéraire de Trieste vers les préoccupations contemporaines de la littérature mondiale à l’époque actuelle où la mondialisation est largement perçue comme le paradigme historique prédominant de la modernité. Ce que j’appelle la « littérature globalisée » renvoie à la refonte de la Weltliteratur – envisagée par Goethe et traduite comme « world literature » ou la « littérature universelle » – par des discours sur la culture mondiale et le post-nationalisme. Cependant, lorsque les études littéraires posent les questions de la « littérature globalisée », elles sont confrontées à un problème : le passage de l’idée universelle inhérente au paradigme de Goethe entre le Scylla d’un internationalisme relativiste et occidental, et le Charybde d’un mondialisme atopique et déshumanisé. Les spécialistes de la littérature mondiale qui tendent vers la première position acquièrent un fondement institutionnel en travaillant avec l’hypothèse implicite selon laquelle les nations sont fondées sur les langues nationales, ce qui souscrit à la relation entre la littérature mondiale et les littératures nationales. L’universalité de cette hypothèse implicite est réfutée par l’écriture triestine. Dans cette étude, je soutiens que l’écriture triestine du début du XXe siècle agit comme un précurseur de la réflexion sur la culture littéraire globalisée du XXIe siècle. Elle dispose de sa propre économie de sens, de sorte qu’elle n’entre pas dans les nationalismes littéraires, mais elle ne tombe pas non plus dans le mondialisme atopique. Elle n’est pas catégoriquement opposée à la littérature nationale; mais elle ne permet pas aux traditions nationales de prendre racine. Les écrivains de Triestine exprimaient le désir d’un sentiment d’unité et d’appartenance, ainsi que celui d’une conscience critique qui dissout ce désir. Ils résistaient à l’idéalisation de ces particularismes et n’ont jamais réussi à réaliser la coalescence de ses écrits dans une tradition littéraire unifiée. Par conséquent, Trieste a souvent été considérée comme un non-lieu et sa littérature comme une anti-littérature. En contournant les impératifs territoriaux de la tradition nationale italienne – comme il est illustré par le cas de Italo Svevo – l’écriture triestine a été ultérieurement incluse dans les paramètres littéraires et culturels de la Mitteleuropa, où son expression a été imaginée comme un microcosme de la pluralité supranationale de l’ancien Empire des Habsbourg. Toutefois, le macrocosme projeté de Trieste n’est pas une image unifiée, comme le serait un globe; mais il est plutôt une nébuleuse planétaire – selon l’image de Svevo – où aucune idéalisation universalisante ne peut se réaliser. Cette étude interroge l’image de la ville comme un microcosme et comme un non-lieu, comme cela se rapporte au macrocosme des atopies de la mondialisation, afin de démontrer que l’écriture de Trieste est la littérature globalisée avant la lettre. La dialectique non résolue entre faire et défaire la langue littéraire et l’identité à travers l’écriture anime la culture littéraire de Trieste, et son dynamisme contribue aux débats sur la mondialisation et les questions de la culture en découlant. Cette étude de l’écriture triestine offre des perspectives critiques sur l’état des littératures canoniques dans un monde où les frontières disparaissent et les non-lieux se multiplient. L’image de la nébuleuse planétaire devient possiblement celle d’un archétype pour le monde globalisé d’aujourd’hui.

Bio-chemical changes associated with processing of shell fishes and flavour constituents of body meat and claw meat'of crab

In this thesis all these aspects are taken into consideration. Extensive studies were conducted on all aspects of processing of crabs, mussels and clams. The species taken for studies are commercially used ones namely Scylla sereta, perna viridis, and villorita cyprinoids. In Chapter 4.1 with regard to crab) the following aspects on their handling and processing are reported seasonal variation of chemical constituents, changes taking place during ice storage, freezing, canning etc. In Chapter 4._2 with regard to mussel, the relation between age (size) and chemical constituents, changes taking place during ice storage, freezing, canning etc. are reported and in Chapter 4.3 the changes taking place in clam muscle during icing and freezing are reported and the ame rebility of ice stored clams for canning purpose is reported.The interference of high concentration of glycogen in mussel and clam muscles during the colour development of ribose (Me-jbaum's method) is observed and remedial step are taken to minimise the interference.

Prevalence of Salmonella in fish and crustaceans from markets in Coimbatore, South India

Seven hundred and thirty fishes and 276 crustaceans collected from various fish markets of Coimbatore, South India, over a period of 2 years (September 1990 to August 1992) were analysed for the prevalence of Salmonella. Fishes (14·25%) and 17·39% of crustaceans were found to be contaminated with Salmonella. Of the different fishes analysed, the highest incidence of Salmonella was seen in Scopelidae (28%) followed by Trachnidae (26·9%). Among crustaceans Portunus pelagicus (33·33%) showed the highest incidence followed by Scylla serrata (28·57%). A well-marked seasonal variation in the incidence pattern was observed in both fishes and crustaceans with a higher incidence during monsoon season followed by post-monsoon and pre-monsoon. The region of the body that showed frequent isolation was the alimentary canal in fishes (41·33%) and gills (35·06%) in crustaceans. Serotyping of the isolates revealed prevalence of Salmonella weltevreden, Salmonella typhi, Salmonella paratyphi B, Salmonella mgulani and Salmonella typhimurium in both fishes and crustaceans. Salmonella senftenberg was isolated only from crustaceans