कालिकट के वेल्लयिल में ड्रिफ्रट जाल मात्स्यिकी की वर्तमान स्थिति

कृपया पूरा लेखा पढ

Instruments and data aquisition systems for research on trawl nets

Catching methods and ways to improve them have been engaging the attention of fishermen from time immemorial. This was done mostly by trial and error methods, as most of the earlier investigations were primarily directed towards solution of biological problems related to fisheries. In recent years several fisheries laboratories have taken up studies on the working principles of many gears such as trawls, gill nets, round haul nets etc. with the aid of instruments developed for the purpose. The purpose of this article is to review the progress made in this field and in the development of telemetering instruments and continuous data acquisition systems

Instrument for the measurement of the fore and aft tilt of otterboards

A portable self-contained instrument has been designed and developed for the measurement of the Fore and Aft tilt of otter boards within the range —22° to + 22° with an accuracy of ± 1°. An underwater transducer fitted on the otter board converts its tilt into corresponding electrical resistance which is measured in an ohmmeter on board, both being connected by electric cable

Major and minor fisheries harbours of India. 9. Fisheries jetty at Minicoy, Lakshadweep

At Minicoy, fish catches are landed on the beach adjacent to the villages on the lagoon side during fair season, October to April-May and therefore a fisheries harbour in its strict sense does not exist there

Observations on spawning in captivity of the clown fish, Amphiprion chrysogaster

For marine aquarium fishes, we fully depend on the exploitation from the wild. In the present account, spawning of the clown fish. Amphiprion chrysogaster kept in captivity at Minicoy is reported

Underwater warp tension meter

A self-contained electronic solid-state instrument capable of measuring the tension between the different parts of a trawl net in operation, has been designed and developed for the measurement in the range 0 to 300 kg with an accuracy of ± 2 kg. The instrument is useful for measuring the resistance to motion of various accessories of a trawl net. It consists of an inductive type underwater tension transducer and an electronic indicating meter kept on board the vessel, both the units being connected by electric cable

Status of tuna fishery in Minicoy, Lakshadweep

The status of tuna fishery at Minicoy is discussed based on the data for the period 1989 -'99. Pole and line using livebaits and troll operate for its fishery of which the former contribute more than 90% of the total tuna catch. The total tuna catch fluctuated from 3071 in 1991 to 1,2431 in 1995 with an average of 8641. The effort in boat days varied from 2,265 in 1996 to 3,896 in 1989 with an average of 2,915. The C/E ranged from 152.2 kg in 1991 to 408.8 kg in 1995 coinciding with the lowest and highest catches respectively. In troll the catch ranged from 91 in 1997 to 281 in 1994 and C/E varied from 8.5 kg in 1997 to 27.7 kg in 1994 corresponding with the lowest and highest catches respectively. Though the pole and line units are operated from September to May in general, the success of tuna fishery depend upon the higher catches in two or three months

Seahorses along Thoothukudi coast

During routine visit to the Mottaigopuram fish landing centre at Thoothukudi on 27.7.2015 and on 20.10.2015, five numbers of seahorses were collected from the fish catch kept for auctioning. These were caught in indigenous trawl operated along the near shore sea grass beds at Thoothukudi. This gear mainly targets juveniles of prawn (especially Penaeus semisulcatus), crabs, cephalopods and fishes. Occasionally stray numbers of seahorses are also caught. The species obtained in the present collections were Hippocampus fuscus, H. trimaculatus and H. spinosissimus

The discovery and exploration of a universal targeting mechanism in eukaryotic cells

A wide range of eukaryotic organisms generate motile cilia and flagella. These slender organelles beat rhythmically to move the surrounding fluid or to propel cells in aqueous environment. Organisms use these powerful yet nimble organelles to forage, evade, adapt and mate. The machinery that drives this tightly controlled movement is the sophisticated microtubule-based axoneme. As it is critical for the survival of individual species, this machinery has largely been preserved to the molecular level throughout evolution. Proteomic studies have shown that most proteins in this biological machine consist of molecular modules commonly used in the cell body. But the usage of these modules is clearly diverged in many cases. This defined machinery with diverged applications provides an opportunity to understand the true capacity of the conserved modules. One example is the radial spoke (RS) that controls the oscillatory beating. This macromolecular complex contains complementary molecular modules that are responsible for localizing cAMP-dependent protein kinase (PKA) in the cell body. However, the RS does not have the features that account for the effector mechanisms of PKA and thus the mechanism discovered for localizing PKA has a broader role that has previously not been recognized. The work described in this dissertation discovered that the core of the RS utilizes two similar sets of PKA anchoring modules for four distinct effector mechanisms that underlie the assembly and function of this regulatory complex. These results elucidate the function of this complex and are applicable to more than 600 diverged proteins that also share the docking module of PKA. Some of them have been shown to play vital roles in myriads of cellular reactions ranging from flagellar beating to trans-Golgi trafficking to chromosome modifications. Founded on this discovery, new reagents and assays were engineered. These tools could be used for the exploration of proteins with similar docking and anchoring modules. Together, these findings will accelerate the advancements in the field of anchoring and docking of proteins in the cell

In situ temperature and salinity meter

Development of a portable self-contained electronic meter for on the spot determination of temperature and salinity is described. Instant and remote measurements of temperature and salinity of sea and estuarine waters in the range of 25-30°C and 30-35°C for temperature with an accuracy ± 0.05°C and 0-37‰ and 31-37‰ for salinity with an accuracy of ± 0.2‰ and ± 0.05‰ respectively are possible with the instrument. The temperature compensations of the salinity measurements are done manually with the help of temperature charts. The temperature and salinity measurements can be fed to continuous recorders