Showing papers in "Aquaculture in 1974"

TL;DR: Methods were developed for the study of turtle grass, Thalassia testudinum Konig, which allow the monitoring of the blade populations without disturbing the plant, and the determination of leaf growth and net production of the blades, in addition to other biotic variables associated with the growth and development of the plant.

TL;DR: Shoot organization in seagrasses varies from the unspecialized condition of Enhalus and Posidonia to the highly differentiated shoot systems of plants like Halophila, Thalassodendron and ThalASSia as discussed by the authors.

TL;DR: It was found that a properly designed water reconditioning-reuse system, under conditions set forth, can provide necessary pollution abatement and increase a hatchery's fish carrying capacity tenfold as compared to a single-pass system.

TL;DR: The reasons behind the interest in siganid mariculture are listed, what is currently known about the biology of siganids considered under fisheries, ecology, reproduction and early development and behaviour are reviewed, and progress made to date is reviewed.

TL;DR: A faunal change of both fishes and epiphytic invertebrates accompanying the decline of the eel Grass beds has been shown, and the significance of eelgrass beds for conservation of inshore fishery resources has been discussed.

TL;DR: The author describes Eucheuma cultivation methods, assesses farm productivity, and considers the economics of EUCheuma farming by Filipino families as well as discussion of current problems and an evaluation of future prospects for the industry.

TL;DR: It is concluded that selection against vibrio disease will result in genetic change and the difference between localities are supposed to be partly heritable.

TL;DR: The standard practices developed and repeated successfully to induce spawning annually under controlled conditions and the method for sampling ova in vivo and the stages of egg development are described and illustrated are described.

TL;DR: Larvae of the portunid crab Scylla serrata were successfully reared using a combination of antibiotics, phytoplankton, Chlorella sp.

TL;DR: Nine species of prawns were compared for their suitability for intensive culture in closed systems and best survival was recorded for P. monodon, which was considerably better than any of the other species.

TL;DR: The first rearing experiments showed that Clarias lazera enjoys a remarkable growth rate and outstanding production qualities, which suggest possibilities for utilization in intensive or rural fish culture if adequate and suitable food for fertilization is available.

TL;DR: Larvae of the grey mullet Mugil cephalus L. can be reared successfully using careful procedures following induced spawning of the adults with purified salmon gonadotropin or human chorionic gonadotropicin, being relevant to the procedures and the techniques applied.

TL;DR: A mathematical model of scallop growth rate as a function of phytoplankton concentration is proposed as a tool for comparing the functioning of different suspension feeders in aquaculture systems.

TL;DR: These experiments indicate that light saturation occurs at very low intensity, which is hyperbolic below 50% light followed by some inhibition at higher intensities.

TL;DR: The combination of retarded photoperiod (6L/18D) and constant temperature of 21°C is the most effective for the completion of vitellogenesis of oocytes to functional maturity.

TL;DR: Radiation gynogenesis was used to investigate the effect of sub-zero cold shocks in inhibiting the second meiotic division of eggs of Atlantic salmon, and if cold shocks were successful in giving rise to diploid gynogenic they could be used to produce triploids from eggs fertilized with non-irradiated spermatozoa.

TL;DR: The characteristic changes in chemical composition of aged culture water, namely an accumulation of nitrate and phosphate and lowering of pH and alkalinity, are discussed.

TL;DR: T transplanting experiments yield much more data concerning seagrass biology than just planting method information, and varietal distinctions based on leaf dimensions are invalid.

TL;DR: The moulting frequency was very variable and, with one exception, did not change proportionately with length or age of the prawns, which achieved larger mean length increments after the environmental conditions were improved.

TL;DR: Factors which limit depth distribution of the species are discussed, as well as results of harvesting experiments which indicate that Thalassia can be safely harvested at least four times a year in Cuba.

TL;DR: Channel catfish were cultured for 177 days in circular tanks containing 1.6 m 3 of water at combinations of five stocking densities (90–720 fish/m 3 ) and five water exchange rates (2.0–0.5 h per exchange).

TL;DR: Four species of rabbitfishes were held in rearing tanks and fed with benthic algae, and out of 101 algae species and 4 vascular plants offered, the fishes ate only 67 species.

TL;DR: It appears that the decreased incidence of Epidermal epithelioma in Israeli fish ponds in recent years has been due to the increased use of selected crossbred carp fry.

TL;DR: The annual production rate of Thalassia testudinum is high compared with plants growing at more northerly latitudes and the shoots may be harvested up to six times a year.

TL;DR: A provisional table of growth rates for sockeye salmon can be used to predict the expected weight for any temperature, time and starting size when on excess ration and were inferior to those of younger cultured sockeye when compared at the same size.

TL;DR: Preliminary experiments with several economically important seaweeds studied their utilization of the major inorganic nutrients contained in secondary sewage effluent and the assimilation of nitrogen and phosphorus was in a ratio, by atoms, which was considerably higher than that commonly found for phytoplankton.

TL;DR: It is proposed that an inexpensive ion exchange column would be useful as a backup system to the microbiological filters, or as an alternate system used while treating diseased animals in culture so as not to harm the nitrifying bacteria of the main biological filters.

TL;DR: Although a drop or a rise in salinity during organogenesis was not observed to influence the survival of eggs, an increase to 41.3‰ did cause a delay in organogenesis, particularly in the development of caudal parts of the embryo, while a decrease to below 28.9‰ resulted in a high proportion of embryos with pericardial or yolk sac hydropsies.

TL;DR: Changes in haematocrit values were studied in vitro in blood samples of asphyxic rainbow trout treated under reduced oxygen tension and with oxygen, showing that the cells were swollen in vivo.