• Length-weight and tail length-total length relationship in Panulirus homarus Linnaeus on the south-west coast of India

      Meenakumari, B.; Mohan Rajan, K.V.; Kesavan Nair, A.K. (1986)
      Length-weight relationships of Panulirus homarus caught from the Kanniyakumari coast was found to be W=0.000566 L super(2-50). The relationship between tail length and total length was also investigated and compared with that of Panulirus polyphagus. Same relationship did not hold good for the two sexes as in the case of P. polyphagus. For a given tail length, the head length, the total length and the weight appear to be relatively larger for females of small sizes of P. homarus.
    • Length-weight relationship and relative condition factor in Daysciaena albida (Cuv.) and Gerres filamentosus (Cuv.)

      Kurup, B.M.; Samuel, C.T. (1987)
      The length-weight relationship of Daysciaena albida and Gerres filamentosus were calculated separately for indeterminants, mature males and mature females. The logarithmic regression equation obtained for D. albida - males: log w = -1.5055 + 2.8618 log l; females: log w = -0.9260 + 2.4089 log l; indeterminants: log w = -l.7188 + 3.0616 log l. The regression co-efficients between males and females, males and in determinants and female and in determinants showed significant differences. In G. filamentosus the relationship can be expressed as males: log w = -1.3224 + 2.8740 log 1; females: log w = -1.2874 + 2.8381 log l; indeterminants: log w = -0.8167 + 2.2558 log l. The difference in regression co-efficients between male and female are insignificant at 5% level whereas significant differences were observed between males and indeterminants and females and indeterminants. The relative condition factor (Kn) was calculated for the above two species. In D. albida the reasons for the fluctuations of Kn values can be attributed to both spawning cycle as well as feeding intensity whereas in G. filamentosus it synchronies mainly with spawning cycle.
    • Length-weight relationship in Nandus nandus (Hamilton) (Perciformes-Teleostei)

      John, K.C.; Balakrishnan Nair, N. (1989)
      Length-weight relationship of the freshwater fish of Pamba River, Nandus nandus (Ham) has been worked out. The results showed that the slope values and elevations were not significant and hence a combined regression equation has been calculated for both the sexes (Log W=2.4130 Log L -0.3306). The’t’ test analyses were conducted and found that the growth departs significantly from the isometric growth. Thus the formula W=aL super(n) has to be applied in calculating the length-weight relationship of this species.
    • Length-weight relationship of Tilapia mossambicus of Idukki Reservoir

      Gopinathan Nair, P. (1988)
      The results of ten months study (September 1983 to July 1984) of the length-weight relationship of males and females of Tilapia mossambicus of the reservoir waters of Idukki Hydel Project show deviation from the cubic relationship of these two parameters. This is due to the retarded growth pattern of this exotic species in this oligotrophic habitat.
    • Length-weight relationship of two palaemonid prawns, Macrobrachium idella and M. scabriculum: a comparative study

      Jayachandran, K.V.; Joseph, N.I. (1988)
      Length-weight relationships of two commercially important freshwater prawns, Macrobrachium idella and M. scabriculum, have been worked out separately for the two sexes of the two species. 't' test showed that growth departs significantly from the isometric growth in the case of both sexes of M. idella and in the female of M. scabriculum. Therefore, the cubic formula W = CL^3 may be applied only in the case of males of M. scabriculum. In all the other cases W = CL^n may be followed.
    • Levels of cadmium in seafood products

      Lakshmanan, P.T. (1988)
      The concentrations of total cadmium were determined in 448 samples of processed fishery products comprising crustaceans, molluscs, marine fish and brackish water fish. Shrimp product, the major export item, contained on average 0.122 ppm cadmium and 20% of crustaceans analysed did not contain cadmium on detectable level. Average content of cadmium in 68 marine fish of 9 species was 0.153 ppm and 35% of the samples did not contain the element. Of the total number of crustaceans analysed only 2% showed a level > 0.5 ppm. All the 174 samples of molluscan products, except 3 canned oysters, showed cadmium concentration far below the limit allowed. The average cadmium content in molluscan products was 0.552 ppm.
    • Life history and behaviour of Indian prawns

      Bhimachar, B.S. (1965)
      Studies on life history and behaviour of prawns form an essential background for the understanding of the disposition of their fisheries and for the formulation of effective methods of exploitation and measures of conservation.
    • Life history of prawns: a review of recent studies with special reference to Indian species

      Krishna Menon, M. (1965)
      The paper contains a brief review of the studies on the life histories of Indian species of prawns chiefly belonging to the family Penaeidae. References to similar work carried out outside India are furnished where significant variations have been observed. The three main larval stages viz., Nauplius, Protozoea and Zoea (Mysis) and their important characteristics, including modes of locomotion, are described. The post-larval development of one species that has been studied in detail (Metapenaeus dobsoni) is indicated in outline. Some aspects of the bionomics of these prawns, especially breeding and migration, are also briefly dealt with in view of their relevance in their life cycle. An outline of the life histories of some Palaemonid prawns of both fresh water and marine habitats is added at the end and the need for well- planned investigations in regard to species of such economic value as Palaemon carcinus (Macrobrachium rosenbergii) is indicated.
    • Lipid breakdown in oil sardine (Sardinella longiceps) during frozen storage

      Nair, P.G.V.; Antony, P.D.; Gopakumar, K.; Rajendranathan Nair, M. (1978)
      The problem of hydrolysis of lipids and consequent accumulation of free fatty acids and development of rancidity due to oxidation of the lipids are major problems in frozen storage of oil sardine (Sardinella longiceps). The course of the phospholipid breakdown, production of free fatty acids and the changes taking place in the major unsaturated fatty acids during frozen storage are described in this paper. The rate of free fatty acid production is faster in the fish, with the higher fat content. Unlike in lean fish, the neutral lipids are found to contribute substantially to the free fatty acid production. The fatty acids most affected during storage are C sub(20:5) and C sub(22:6). The polyene indices were found to decrease during storage. These effects are more pronounced in the fish with the higher fat content.
    • Lipid distribution in body and skin of four species of marine fish

      Mathew, P.T.; Devadasan, K.; Venkataraman, R. (1977)
      The paper presents results of a study on the analytical characteristics of lipids from the skin and muscle of four important species of Gujarat coast fishes. Changes in characteristics like saponification value, iodine value and unsaponifiable matter of these lipids during different months of the year are also reported.
    • Lipid hydrolysis in mackerel (Rastrelliger kanagurta) during frozen storage

      Nair, P.G.V.; Gopakumar, K.; Rajendranathan Nair, M. (1976)
      The hydrolytic changes in the lipids of mackerel (Rastrelliger kanagurta) during storage at -l8°C were studied with a view to understand the factors involved in the formation of free fatty acids. Only the phosphorylated fraction did undergo hydrolysis at an appreciable rate. It was found that the free fatty acid production was mainly associated with the phospholipid hydrolysis. As regards the triglycerides and unsaponifiable matter, there was no significant change in levels during frozen storage.
    • Low cost freshwater fish pickle using cheap citrus fruit (C. reticulata)

      Chattopadhyay, A.K.; Bandyopadhyay, J.K.; Batthacharyya, S.K. (1986)
      The juice extracted from a locally abundant cheap variety of citrus fruit namely, Citrus reticulata was utilized for pickling. The paper highlights the trials made to select the optimum concentrations of acetic acid and sodium chloride to be used along with the juice of C. reticulata so as to obtain the best, product. The product can be stored well at room temperature for six months.
    • Lunar, diurnal and tidal periodicity in relation to the prawn abundance and migration in the Godavari estuarine systems

      Subramanyam, M. (1965)
      Preliminary investigations to study the lunar, diurnal and tidal periodicity in abundance and migrations of prawns were made in the Bairavapalam distributary of the Goutami branch of the Godavari estuary during the period of November 1961 to July 1962. The study was based on observation of the catches of a stake net (bag net) operated near the mouth of the estuary. Records of the catches were maintained tidewise daily. Comparative estimates of abundance were made on the basis of catch per hour's operation. It was generally observed that the catches were higher during the darker half of the month than in the brighter fortnight. The landings during low tides were generally higher than those during high tides and usually heavier catches were made during nocturnal low tides than during the day low tides. A continuous inward and outward (immigration and emigration) movement of prawns of all size groups was observed in the estuary from November to July. In general, more penaeid prawns were found to be immigrating at dawn than at dusk. Similarly, the number of emigrants was also found to be generally higher during the new moon period than during the full moon. Metapenaeus monoceros showed an almost distinct nocturnal periodicity in migration, while no such periodicity was observed, distinctly, in other species. In the case of Penaeus indicus the movement of migrants was prolonged. In M. brevicornis the migrants were scarce till March and thereafter increased numerically. The migrant forms of Metapenaeus dobsoni continued to be abundant till May with peak periods in January and February. The migratory pattern of Metapenaeus affinis was similar to that of Metapenaeus brevicornis, though the migrants of the former species appeared a month earlier than the latter. Intensive studies over extended areas for longer periods are required to understand clearly the migratory pattern of the various species. The phenomenon of immigration of prawns can be clearly understood only by vital staining or tagging studies. Perhaps the emigrants might be returning with the succeeding changing life. To verify this, laboratory experiments, by vital stains, were conducted. The marked specimens, if released during the low tides on a large scale, may be recaptured during the subsequent high tides and the duration also may be calculated. At least some percentage of the emigrants remains in the sea for maturity and breeding.
    • Measurement of moisture in dry cured fish by infrared irradiation

      Rao, C.V.N.; Balachandran, K.K.; Govindan, T.K. (1967)
      Heating conditions have been standardised for measurement of moisture in dry cured fish using infrared irradiation source of 150w. Results obtained are comparable to those obtained from standard air oven method (drying to a constant weight at l02°c), the mean deviation being less than two units. The method works equally well for fresh fish muscle.
    • Mercury toxicity in two intertidal tropical marine molluscs

      Ekanath, A.E.; Menon, N.R. (1983)
      Lethal and sub-lethal effects of mercury have been studied in Perna viridis and Modiolus carvalhoi. For P. viridis LC30 is 1.0 p.p.m. at 48 h and 0.23 p.p.m. at 96 h. Recorded LC50 values for M. carvalhoi are 0.5 p.p.m. and 0.19 p.p.m. at 48 h and 96 h respectively. The results document that these two species, although inhabiting the same area in the tidal belt, exhibit clear differences in mercury resistance. It is further shown that the duration of exposure affects mortality rates. In sub-lethal concentration, between 0.01 and 0.10 p.p.m. decrease in pedal-gland activity is conspicuous in P. viridis. At concentrations much below LC50 values (at 96 h), although some animals are alive, pedal-gland activity is totally suspended, supporting the assumption that shell closure ability plays a minor role in byssus thread production. In M. carvalhoi total cessation of pedal gland activity occurred at 0.09 p.p.m. of mercury.
    • Mesh regulation in backwater prawn fishing gear

      George, V.C.; Gopalan Nayar, S.; Krishna Iyer, H. (1974)
      Size grade composition of different species of prawn caught by various back water fishing gear have been enumerated.57 to 75% of P. indicus captured was less than 10 cm in length. M. dobsoni and M. monoceros captured were less than 10 cm in length. A cod end mesh size of 20-25 mm has been recommended for stake nets for the capture of P. indicus of 10 cm length along with other species.
    • Mesh selectivity for spotted seer, Scomberomorus guttatus (Bloch & Schneider)

      Sreekrishna, Y.; Rao, J.S.; Dawson, P.; Mathai, T.J.; Sulochanan, P. (1972)
      An attempt has been made to evolve a suitable mesh size for the commercially significant size group of S. guttatus. To obtain maximum sustainable yield taking biological factors also into consideration, 52 mm mesh bar nets are suggested for exploiting the fishery on both the East coasts of India.
    • Methionine content of some of the important species of Indian fishes

      Gowri, V.; Vasantha, M.S.; Srinivasan, K.S.; Moorjani, M.N. (1972)
      A very little work is reported on the methionine content of Indian fishes. This work was therefore undertaken to determine the methionine content of some of the important varieties of Indian fishes.
    • Methods of sensory evaluation of quality and application of statistical methods in sensory evaluation problems with special reference to fishery products

      Krishna Iyer, H. (1972)
      The quality of raw and processed fishery products depend on several factors like physiological conditions at the time of capture, morphological differences, rigor mortis, species, rate of icing and subsequent storage conditions.Sensory evaluation is still the most reliable method for evaluation of the freshness of raw processed fishery products. Sophisticated methods like Intelectron fish tester, cell fragility technique and chemical and bacteriological methods like estimation of trimethylamine, hypoxanthine, carbonyl compounds, volatile acid and total bacterial count have no doubt been developed for accessing the spoilage in fish products.
    • Microbiological evaluation and keeping quality of fishes reared in livestock sewage fed ponds without artificial feed

      Bachhil, V.N. (1981)
      Livestock sewage has been utilized for fish culture. There is lack of information on microbiological evaluation and keeping quality of these fishes. This paper reveals the incidence, types of micro-organisms and keeping quality of fishes reared in livestock sewage fed ponds without artificial feed. These fishes revealed microbial incidence and keeping quality comparable to other fishes. Initial mesophilic and psychrophilic counts varied from 3.38 to 5.56 and 2.47 to 4.74. On an average, the counts reduced by about 40% after evisceration and washing. Whole as well as washed fishes had refrigerated (8 ± 1°C) life of not more than 4 days. The average psychrophilic and mesophilic counts of ice (0 to 1°C) stored whole fishes up to 10th day varied from 3.66 to 4.81, 4.61 to 5.24 and in eviscerated and washed fishes 2.17 to 3.69 and 2.78 to 4.41. Both remained acceptable till the 10th day. Qualitative study of surface slime and gills revealed presence of Aerobacter (Enterobacter), Aeromonas, Alcaligenes, Bacillus, Clostridia, E. coli, Klebsiella, Micrococci, Proteus and Pseudomonas.