Marine Pearl Culture

Pearls are one of the gems which has a worldwide demand and has been exploited from the time immemorial. Pearl fishing was prominent all over the Middle East and Oriental countries during the early 4000 BC. The use of pearls as ornaments was well exhibited in the Egyptian civilisation as well as Sind Valley civilisatio

Microparticulated and microencapsulated diets for feeding prawn and bivalve larvae

Food is normally the largest single item in the running expenditure in fish and shellfish farming. Hence the suitability and cost effectiveness of the ration is of paramount importance to commercial success, many different types of feed may require development to meet the varied needs of different species and size of larvae. Palatability and physical structure of shrimp and bivalve ration are inter-related. Both factors alone and in conjucation affect ingestion and have an important impact on prawn and bivalve nutrition. Microencapsulated diet for larval and postlarval diets have been advocated by Meyers (1973). Gelatin microencapsulated diets suitable in sea water. Until the development of microparticulated diets the recent years the. study of larval nutrition was impossible

Freezing of viable embryos and larvae of marine shrimp, Penaeus semisulcatus de Haan

Although sperm cryopreservation has been carried out successfully in a number of commercially important aquatic species, particularly in some teleost fish (see review of Rana in Muir & Roberts 1993) and also shellfish (Subramoniam 1993), the technology is still not at the stage of advanced commercial application that is seen in domestic mammals. Cryopreservation of eggs and embryos, of aquatic animals however, is a virgin field in cryobiology and has not yet received any appreciable amount of attention. The first successful attempt at the cryopreservation of embryos of sea urchin was reported by Asahina & Takahashi (1978). Later Zell (1978) and Erdahl & Graham (1980) have reported preliminary attempts to freeze the eggs of rainbow trout

Carbohydrate requirements of finfish and crustaceans

Nutrition supplies the raw materials for the maintenance of life. Some materials are used, for the formation of body tissues (anabolism) and some for the production of energy (catabolism). Foods may be classified as energy and growing foods carbohydrates (CHO), fats and proteins and non energy foods (Minerals, vitamins, water and oxygen). Nutrition of fish has received attention for many years. The nutritional value of a diet is measured by the presence of necessary elements and catalysts an abundant supply of the anxillary foods and a proper balance between the energy and growing foods, A proper balance between the energy and growth foods assures an adequate supply of both energy and raw materials for optimum anabolic activity which in addition to growth includes tissue repair, reproduction and the formation of essential body products

Techniques for the mass culture of rotifers and moina

Successful hatchery production of fish and shellfish seeds for aquaculture depends on the availability of suitable live feed organisms

Larval rearing trials of the honeycomb grouper Epinephelus merra Bloch under laboratory conditions

Groupers being economically important food fishes are experimented widely for controlled breeding world over. In India, attempts were made on few species of the genus Epinephelus such as E. tauvina, E. malabaricus and E. polyphekadion at the Central Marine Fisheries Research Institute and limited success was achieved. The present paper discusses on larval rearing trials of the honeycomb grouper E. merra up to juvenile stage. Larvae measuring 1.3 – 1.6 mm obtained from the captive spawning of broodstock of E. merra were used for the larval rearing studies. The feeding protocol, water exchange and larval rearing methods adopted are detailed. The larval mouth opening appeared on day 3 post-hatch. The larvae gradually metamorphosed into juvenile by day 60 and attained a size of 45 mm. The possible reasons for initial mortality, the advantage of HUFA rich feeding and effect of large volume of rearing tanks on the growth and survival of the larvae are discusse

Implementation of Fault-tolerant Quantum Logic Gates via Optimal Control

The implementation of fault-tolerant quantum gates on encoded logic qubits is considered. It is shown that transversal implementation of logic gates based on simple geometric control ideas is problematic for realistic physical systems suffering from imperfections such as qubit inhomogeneity or uncontrollable interactions between qubits. However, this problem can be overcome by formulating the task as an optimal control problem and designing efficient algorithms to solve it. In particular, we can find solutions that implement all of the elementary logic gates in a fixed amount of time with limited control resources for the five-qubit stabilizer code. Most importantly, logic gates that are extremely difficult to implement using conventional techniques even for ideal systems, such as the T-gate for the five-qubit stabilizer code, do not appear to pose a problem for optimal control.Comment: 18 pages, ioptex, many figure

Indian experience of large scale cultured marine pearl production using Pinctada fucata (Gould) from southeast coast of India: A critical review

In India, research on marine pearl culture was started in 1972 and the first cultured marine pearl from Pinctada fucata was rolled out a year later through the earnest efforts of Central Marine Fisheries Research Institute, Kochi (CMFRI) at its Tuticorin Research Centre. Subsequently, improvements of the technology were made by various scientists involved at different centres of CMFRI focussing on different issues of marine pearl culture. Information on different aspects of marine pearl culture such as surveys for stock position, ecology of pearl beds, small scale experimental culture of mother oysters, surgical nucleation and spherical pearl and designer pearl production (‘mabe’) has already been published in various sources including few instances of technology transfers to entrepreneurs/fisher folk. Though, the experimental results were encouraging, anticipated technology transfer did not take place subsequently. Hence a large scale marine pearl culture demonstration was carried out and viability of the technology was redemonstrated at the Regional centre of CMFRI, Mandapam Camp during 1997 - 2003 through an ICAR Revolving Fund Project which resulted in wealth of information regarding different aspects of marine pearl culture. In the present account, the lessons learnt based on the published information as well as the data (unpublished) obtained in the large scale culture are analysed and classified under the critical activities of pearl culture and presented in the form of a ‘non systematic critical review’ essentially to arrive at the status of marine pearl culture in India

Socio-hydrologic drivers of the pendulum swing between agricultural development and environmental health: A case study from Murrumbidgee River basin, Australia

This paper presents a case study centred on the Murrumbidgee River basin in eastern Australia. It illustrates the dynamics of the balance between water extraction and use for food production, and efforts to mitigate and reverse consequent degradation of the riparian environment. In particular, the paper traces the history of a pendulum swing between an exclusive focus on agricultural development and food production in the initial stages and its attendant socio-economic benefits, followed by the gradual realization of the adverse environmental impacts, subsequent efforts to mitigate these with the use of remedial measures, and ultimately concerted efforts and externally imposed solutions to restore environmental health and ecosystem services. The 100-year history of development within the Murrumbidgee is divided into four eras, each underpinned by the dominance of different values and norms and turning points characterized by their changes. The various stages of development can be characterized by the dominance, in turn, of infrastructure systems, policy frameworks, economic instruments, and technological solutions. The paper argues that, to avoid these costly pendulum swings, management needs to be underpinned by long-term coupled socio-hydrologic system models that explicitly include the two-way coupling between human and hydrological systems, including the slow evolution of human values and norms relating to water and the environment. Such coupled human-water system models can provide insights into dominant controls of the trajectory of their co-evolution in a given system, and can also be used to interpret patterns of co-evolution of such coupled systems in different places across gradients of climatic, socio-economic and socio-cultural conditions, and in this way to help develop generalizable understanding. © 2014 Author(s)

On the large sunfish landed near Mandapam

A sunfish, Ranzania laevis (Pennant) measuring 660 mm total length was caught on 5.3.1998 in shoreseine near Mandapam in Palk Bay. In fresh condition its colour was bluish with dark above and pale white below with small hexagonal plates and smooth skin. Six streaks of lighter colour bordered with dark descended from snout to gill slits and curved downwards to the ventral profile. The posterior three streaks were branched with dark spots. The lips were produced forward beyond the teeth closing as a vertical slit