摘要:

ABSTRACTFeed ingestion and assimilation of dry matter, total lipid, total carbohydrate and inorganic material by adult, maleMacrobrachium rosenbergii(de Man) were measured at temperatures ranging from 22–34°C. Assimilation efficiency of dry matter was measured gravimetrically. Significantly less feed was ingested by prawns at water temperatures below 25°C than at higher temperatures. Water temperatures had little effect on the assimilation efficiency of dry matter, although there was a trend toward decreased dry matter assimilation at high temperature extremes. There was no effect of water temperature on assimilation efficiencies of lipid, carbohydrate or inorganic material. It is proposed that feed ingestion and metabolic rates are affected more by water temperature and are more responsible for differences in growth rates than is the efficiency of feed assimilation.Regurgitation was a consistent occurrence following feeding by prawns and accounted for a significant proportion of egested material. It is suggested that regurgitation results in energetic benefits to the prawn, owing to a decreased energy requirement because unassimilable material need not be transported through the entire digestive system. There may also be an increase in the rate of energy intake due to the clearance of ingested, but unassimilable, material from the proventriculus. The absorption of minerals from the diet and the phenomenon of regurgitation are taken into account in a critical discussion of assimilation determination methods used for aquatic invertebra

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00016.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThree methods of harvesting Hawaiian freshwater prawn ponds are described: 1) Traditional (also called “Fuji,” after Fujimura, or “hukilau,” Hawaiian for community net fishing)‐A seine is maneuvered around the pond by workers in the water who drag the net lead line with their feet as they encircle the catch. The seine is then closed into a bag and the prawns are removed. 2) Modified seining‐A seine which spans the width of the pond is pulled from both ends simultaneously by tractors. The seine is pulled from one end of the pond to the other, concentrating the catch in the bag or live car enclosure. 3) Drain harvesting‐Water is drained from the pond by gravity or by pumping, the screen is removed from the catch basin and a fish pump is used to pump the prawns into a dewatering box. The prawns are then transferred to holding tanks for sorting.The efficiencies and cost effectiveness of all three methods are discussed with recommendations relative

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00017.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTFreshwater prawn Farming in Thailand is relatively extensive, i.e., with low stocking rate and low yield, as compared to Hawaii. However, the cost of production per kg of marketable prawns is comparatively low due to inexpensive inputs. The low costs of production and current high price of prawn in Thailand resulted in a high profit. In Hawaii, despite the high yield, the profitability of prawn Farming is low at the present time because of the high costs of production.

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00018.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThe inability of shrimp culturists to produce sufficient quantities of fertilized penaeid eggs in captivity has sustained the practice of collecting mature wild females offshore for immediate spawning. However, in the case of open thelycum penaeids, offshore collections are often unproductive because mature wild females are seldom found in the mated (spermatophore attached) condition. In this study, artificial insemination was investigated as a means of obtaining fertilized eggs from unmated mature femalePenaeus setiferuscollected offshore.A total of 59 artificial inseminations were performed in conjunction with 4 cruises in the western Gulf of Mexico. Sperm was removed from spermatophores of males found within the catch and attached between the third and fourth pairs of pereiopods of unmated, mature females which were then chilled to 20°C to inhibit spawning until return to the laboratory. Of 53 spawns produced by artificially inseminated females, at least 41 (77%) resulted in fertilized eggs and nauplii (range: 100 to 260,000 nauplii per spawn). Of the 41 fertile spawns, 29% produced 50,000 or more nauplii and 20% produced more than 100,000 nauplii per spawn. Approximately 2 million larvae were produced by artificial insemination, while only about one million were obtained from naturally mated females on the same cruises. Thus, the production of nauplii from the cruises was tripled by using artificial insemination in addition to spawning of naturally inseminated females

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00019.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTAssimilation (apparent digestibility and absorption) of protein and carbohydrate from selected diets was tested usingPenaeus stylirostris. The largest shrimp (approximately 10 g) assimilated squid meal proteins better than α‐soy protein but smaller shrimp (1.3 and 3.8 g) did not. All sizes assimilated protein from diets containing α‐soy better than those containing brewer's yeast. Carbohydrate assimilation was less efficient than protein for all diets. There was no relation between carbohydrate and protein assimilation and the percentage in the diets over the limited range tested. Although assimilation of these two groups of compounds was greater in the larger shrimp, there was no correlation between the growth and protein and carbohydrate assimilation for the diets tested for similar size animals of the same sp

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00020.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTSince 1978, polyculture experiments of pompano (Trachinotus carolinus) and shrimp have been conducted in the Centro de Investigaciones Científicas, Universidad de Oriente, Venezuela. Experiments are carried out in circular concrete ponds (28 m2) with running seawater (salinity 37–39 ppt and temperature 26.4–30.9°C) and constant aeration. In the first experiment (September‐December 1978) pompano and shrimp were stocked at a density of 10/m2and were fed withTivela mactroides(Mollusca, Pelecipoda) “guacuco” pellet of 60% crude protein. Pompano 0.22±0.1 g reached after 75 days 40.6±25.6 g with food conversion of 6.59 and 17.14% survival; shrimp 1.3±0.4 g reached a weight of 5.7±0.9 g and 2.68% survival during 75 days. The common food conversion was 7.57.The second experiment (June‐August 1981) was carried out in tanks with a false bottom. Pompano and shrimp were stocked at densities of 5 and 10/m2respectively, and were fed with a pellet named GSCA (42.8% crude protein). Pompano 4.0±1.1 g reached 62.1±10.3 g after 75 days of culture, the food conversion and survival being 3.1 and 64.29%, respectively. Shrimp stocked at 3.6±0.6 g reached 8.9±1.8 g after 75 days, and feed conversion was 10.7 with 54% survival. The common feed conversion for pompano and shrimp was 6.6. After 75 days of culture the high mortality of pompano was due to the infection of branchial parasites, the protozoaAmyloodinium ocellatumand the trematodeBic

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00021.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00022.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTInvestigation was carried out on the diseases of culturedPenaeus semisulcatusat various stages of their life cycle. Major diseases were bacterial necrosis, Vibrio infection, infestation by filamentous bacteria, shell disease, fungal infections (Lagenidiumsp. andFusariumsp.) and protozoan infection. Various antibacterial antifungal and parasiticides were examined to establish effective methods for disease control. Most disease episodes were associated with poor water quality following failure in water supply.

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00023.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTBlack mangrove (Avicennia germinans) were grown from seed in a closed synthetic seawater system to a maximum height of 165 cm and trunk diameter of 20 mm in 24 months. Plants were maintained in glass aquaria in 63 mm of crushed coral and shell substrate and received continual flow from a 28,387 liter system. Seedlings were planted in aquaria 18, 30 and 46 cm deep but only those in 18 cm aquaria survived. The entire system is housed in a modified greenhouse and only ambient light was provided. Average salinity was 27 ppt (range 17–34 ppt), temperature 26.2°C (range 21.3 to 30°C), pH 8.05 (range 7.8‐8.3), nitrate‐N 52.3 ppm (range 38–66 ppm) and phosphate‐P 0.568 ppm (range 0.078‐1.080 ppm). Additions of a trace metal solution were made during the l

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00024.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTThe culture of penaeid shrimp in grow‐ponds in Ecuador is expandin: at a rapid rate. Coastal, low lying, salt flats adjacent to estuarine waters, unsuited for classical agriculture, are being transformed into productive shrimp farming areas. Currently, post‐larval “seed” shrimp must be collected from the wild to stock the ponds. The Ecuadorian Government is concerned, however, that this practice may affect production from the trawl fishery.A hatchery facility with the capacity of producing 5 million postlarval shrimp per month is planned by the Ecuadorian government. This should help eliminate part of the demand for post‐larval shrimp from the wild stock. Also, an extension service is being developed to aid the shrimp farmers.An on‐site visit and description of Ralston Purina's hatchery facilities in Panama, Central America, is al

ISSN:0735-0147    

DOI:10.1111/j.1749-7345.1982.tb00025.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY