23 resultados para Grey, George, Sir, bart., 1799-1882.
em Aquatic Commons
Resumo:
The geometric mean regression equation for the weight; length relationship of Cynoglossus canariensis was W = 0.0025 L super(3.1770). The Von Bertalanffy constants Woo, Loo, K, and to were 507.5852 g, 47.3683 cm, 0.3333 and 0.1397 for males and 839.0753 g, 54.4720 cm, 0.3062 and 0.1737 for females. Total mortality coefficient Z ranged from 0.6482 and 0.8021
Resumo:
An obituary of the limnologist G.E. Hutchinson is given.
Resumo:
Morphological observations of the dinoflagellate Ceratium hirundinella are given and a key to the difference in types provided. Illustrations are included.
Resumo:
Cynoglossus canariensis has a very rapid growth. The rate of the males is 0,36 and the female one is 0,32. The asymptotic size is 55,0cm for the females and 50,5cm for the males. Females and males younger than three years (40cm), which represent 90 per cent of the Côte d'Ivoire stock have a similar growth, so the average equation: Lt=53,5 (1-e -0,34(t+1)) will be used.
Resumo:
Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. Conclusions/Significance: Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch’s Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate
Resumo:
Samples of 11,000 King George whiting (Sillaginodes punctata) from the South Australian commercial and recreational catch, supplemented by research samples, were aged from otoliths. Samples were analyzed from three coastal regions and by sex. Most sampling was undertaken at fish processing plants, from which only fish longer than the legal minimum length were obtained. A left-truncated normal distribution of lengths at monthly age was therefore employed as model likelihood. Mean length-at-monthly-age was described by a generalized von Bertalanffy formula with sinusoidal seasonality. Likelihood standard deviation was modeled to vary allometrically with mean length. A range of related formulas (with 6 to 8 parameters) for seasonal mean length at age were compared. In addition to likelihood ratio tests of relative fit, model selection criteria were a minimum occurrence of high uncertainties (>20% SE), of high correlations (>0.9, >0.95, and >0.99) and of parameter estimates at their biological limits, and we sought a model with a minimum number of parameters. A generalized von Bertalanffy formula with t0 fixed at 0 was chosen. The truncated likelihood alleviated the overestimation bias of mean length at age that would otherwise accrue from catch samples being restricted to legal sizes.
Resumo:
Sex ratio data of two species of penaeid prawns Metapenaues kutchensis George, George and Rao, 1963 and Parapenaeopsis sculptilis (Heller, 1862), occurring in the Gulf of Kachchh, were statistically analysed. A preponderance of females was observed in both the species and the ratio of male to female for both years combined for M. kutchensis and P. sculptilis was found to be 1:15 and 1:2.7, respectively. Chi-square analysis revealed significant difference in the sex ratio of the two species.
Resumo:
This study aimed at evaluating the production levels in terms of catch estimates of the artisanal fisheries of the Edward-George system in addition to providing information on the facilities and services at landing sites and the composition, magnitude and distribution of fishing effort to guide development and management of the fisheries resources of the Edward and George lakes and Kazinga channel. Specifically, the study was expected to come up with the following outputs:- a) Information on the number of fish landing sites on the basin lakes; b) Information on the facilities available at the fish landing sites to service the fisheries sector ; c) Information on the number of fishers; d) Information on the number and types of fishing crafts; e) Information on the modes of propulsion of the fishing crafts; f) Information on the number types and sizes of fishing gears including the number of illegal fishing gears in the fishery; and g) Recommendations on development and management of the fisheries of the Edward and George lakes and Kazinga channel. h) Beach values in terms of annual catches and annual revenue from the water bodies.
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The results are presented of attempts to artificially fertilize Mugil cephalus eggs in the Philippines. Embryonic development is outlined and rearing of the larvae described. Mass mortality occurred during week 3 of rearing.
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The culture potential of hatchery-produced grey mullet (Mugil cephalus, Linnaeus) stocked with average weight of 3.7 g and at 2,500 (treatment I) and 3,000 (treatment II) fingerlings/ha in six 350m brackishwater ponds following the lab-ab method of culture was studied.