Effect of protein source and level on growth and performance of the captive freshwater prawn,Macrobrachium rosenbergii     

George H. Balazs  Ernest Ross 《Aquaculture (Amsterdam, Netherlands)》1976,7(4):299-313

Growth, feed conversion and survival were determined for juvenile Macrobrachium rosenbergii held in tanks under semi-controlled environmental conditions. Feeding trials incorporated water-stable diets at three levels of protein (15, 25 and 35%). The principal protein source combinations consisted either of soybean and tuna meal, or of soybean, tuna and shrimp meal. In a 244-day comparison of these diets, higher protein content produced larger prawns (P < 0.01), but differences between sources were not significant. No significant differences existed between feed conversion ratios (range 1.36–1.72) or percentage survival (range 90.3–93.6%). Trials of several other diets were also conducted, including soybean and Tilapia meal, and copra and Tilapia meal (25% protein level) as principal protein source combinations. After 167 days on these diets, growth was inferior to that obtained with soybean and tuna meal or soybean, tuna and shrimp meal combinations. No significant differences existed between feed conversion ratios or percentages of survival.For the 244 days, a control group of prawns received no formulated diet. Growth and survival in this group during the first 110 days suggested that naturally occurring algae contributed substantially to the prawns' nutrition.Mean prawn length after 244 days on the best diet (35% protein from soybean and tuna meal) was 73 mm, and growth rate was equivalent to that achieved under pilot pond conditions.  相似文献   

The Chinese grass carp, Ctenopharyngodon idella, its biology,introduction, control of aquatic macrophytes and breeding in the Sudan     

T.T. George 《Aquaculture (Amsterdam, Netherlands)》1982,27(3):317-327

The paper describes the distribution and biology of the grass carp following its introduction into Sudan. It provides aspects on the culture of the grass carp and its breeding under Sudanese conditions with emphasis on future research.  相似文献   

VH1-44 gene usage defines a subset of canine B-cell lymphomas associated with better patient survival     

Hsiao-Wei Chen  George W. Small  Alison Motsinger-Reif  Steven E. Suter  Kristy L. Richards 《Veterinary immunology and immunopathology》2014,157(3-4):125-130

The use of specific immunoglobulin heavy chain variable region (VH) genes has been associated with increased patient survival in human B-cell lymphomas (hBCL). Given the similarity of human and canine BCL (cBCL) in morphology and clinical treatment, we examined the choice of VH in cBCL and determined whether VH gene selection was a distinct feature associated with survival time in dogs. VH gene selection and mutational status in 52 cBCL, including 29 diffuse large B-cell lymphomas (cDLBCL, the most common subtype of cBCL), were analyzed by comparison with the 80 published canine germline VH gene sequences. We further examined the prognostic impact of the subgroups defined by these features on canine survival. We found that VH1-44 was preferentially expressed in the majority of the 52 cBCLs (60%) as well as in the majority of the cDLBCL subset (59%). VH1-44 gene expression was associated with a statistically better overall survival (p = 0.039) in cBCL patients, as well as in the cDLBCL subset of patients (p = 0.038). These findings suggest that VH gene selection in cBCL is not random and may therefore have functional implications for cBCL lymphomagenesis, in addition to being a useful prognostic biomarker.  相似文献   

Climate variability and marine survival of coho salmon (Oncorhynchus kisutch) in the Oregon production area   总被引：1，自引：0，他引：1  

J. Anthony Koslow  Alistair J. Hobday  & George W. Boehlert 《Fisheries Oceanography》2002,11(2):65-77

Time series of adult recruitment for natural runs of coho salmon from the Oregon coastal region (1970–94) and marine survival of hatchery-reared coho salmon from California to Washington (1960–94) are significantly correlated with a suite of meteorological and oceanographic variables related to the biological productivity of the local coastal region. These variables include strong upwelling, cool sea surface temperature (SST), strong wind mixing, a deep and weakly stratified mixed layer, and low coastal sea level, indicating strong transport of the California Current. Principal component analysis indicates that these variables work in concert to define the dominant modes of physical variability, which appear to regulate nutrient availability and biological productivity. Multiple regression analysis suggests that coho marine survival is significantly and independently related to the dominant modes acting over this region in the periods when the coho first enter the ocean and during the overwintering/spring period prior to their spawning migration. Linear relationships provided good fits to the data and were robust, capable of predicting randomly removed portions of the data set.  相似文献   

Reference intervals and age‐related changes for venous biochemical,hematological, electrolytic,and blood gas variables using a point of care analyzer in 68 puppies     

Mauria A. O'Brien DVM  DACVECC  Maureen A. McMichael DVM  DACVECC  Kevin Le Boedec DVM  MS  George Lees DVM  MS  DACVIM 《Journal of Veterinary Emergency and Critical Care》2014,24(3):291-301

  相似文献   

Early Development of the Mandarinfish, Synchiropus splendidus (Callionymidae), with notes on its Fishery and Potential for Culture     

Yvonne Sadovy  George Mitcheson  Maria B. Rasotto 《Aquarium Sciences and Conservation》2001,3(4):253-263

The mandarinfish, Synchiropus splendidus, is a small, pelagic-spawning enthic dragonet of the western Pacific. Although popular in the marine aquarium trade, little is known of its fishery or biology. All aquarium-trade animals are currently taken from the wild and the impact of heavy collecting is unknown. The specialized and selective nature of the fishery for mandarinfish is described and its potential to disrupt the mating system identified. As a possible alternative to wild capture and as an aid to sustainable exploitation, egg production and early development relevant to mariculture are described, including egg output, embryo, larva and post-settlement development to 30 days, based on live material. Egg output was determined for 40 females and ranged from 12 to 205 eggs. Embryo and larva development were rapid, with settlement occurring within 14 days at 24–26 °C, and at 3.5 mm TL. The swimbladder is retained in adults. Our limited attempts at raising the mandarinfish to settlement were encouraging and suggest an excellent potential for mariculture with implications for both conservation and improved maintenance of fish in captivity. At present, given that this species is difficult to maintain in captivity, it is only suitable for experienced aquarists. Preliminary diet information is provided. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Effect of organic fertilizer on plankton primary productivity in fish ponds   总被引：2，自引：0，他引：2  

Doychin Terziyski  George Grozev  Roumen Kalchev  Angelina Stoeva 《Aquaculture International》2007,15(3-4):181-190

The effect of cattle organic fertilizer on plankton primary production and related variables was tested in six Bulgarian fish ponds situated close to the town of Plovdiv in Bulgaria. At the beginning of the experiment (16th of May 2004, about 10 days after filling with water) a suppression of plankton metabolism was observed and after that the ponds treated with manure demonstrated significantly higher productivity than the controls, especially during the transition to the autumn season when the water column was more regularly mixed. The other measured variables (Secchi disk readings, plankton chlorophyll-a and respiration, assimilation number per unit chlorophyll-a) did not show significant differences between the treated and control ponds.  相似文献   

The establishment and impact of Pseudorasbora parva,an exotic fish species introduced into Lake Mikri Prespa (north-western Greece)     

Elisabeth Rosecchi  Alain J. Crivelli  George Catsadorakis 《水产资源保护:海洋与淡水生态系统》1993,3(3):223-231

• 1. The topmouth gudgeon Pseudorasbora parva Schlegel, 1842, a south-east asian cyprinid, was introduced accidentally in the Danube Delta in Romania in the 1960s and has now achieved a pan-Danubian distribution. P. parva has been introduced into other countries, such as Greece, usually inadvertently included with other species imported for fish farming. In 1984–85, during a study of the fish populations of Lake Mikri Prespa (north-west Greece), several topmouth gudgeon were caught. Our aim was to study the changes in the population size of P. parva over nearly 10 years, to study its life history traits and to assess its potential impacts on native fish species.
• 2. The catch per unit effort (CPUE) in spring increased significantly between 1984 and 1992. We found evidence that P. parva has established a breeding population in the lake. P. parva combines many characteristics likely to favour a successful colonization (resistance to harsh climatic conditions, early sexual maturity, extended breeding season, broad dietary spectrum). Growth in Lake Prespa, where the oldest individuals captured were 3 years old, is very similar to that observed within its native range.
• 3. There is evidence for dietary overlap between P. parva and three endemic species: Paraphoxinus epiroticus prespensis, Cobitis meridionalis and Alburnoides bipunctatus ohridanus. No decline in the populations of these three species has yet been demonstrated. Other possible impacts are discussed. The successful colonization by P. parva was certainly favoured by the absence of a true piscivorous fish in the lake and by the isolation and high level of endemism of fish communities.
• 4. The conservation of the many endemic species in the lake should be a priority and the introduction of exotic species should be banned.

  相似文献   

Metallothionein induction in cultured fibroblasts and liver of a marine flatfish,the turbot,Scophthalmus maximus     

Stephen George  David Burgess  Michael Leaver  Nick Frerichs 《Fish physiology and biochemistry》1992,10(1):43-54

Intraperitoneal injection of turbot with Cd induced the synthesis of a low molecular weight hepatic Cd-binding protein and a 500bp mRNA, which hybridised to a plaice metallothionein (MT) cRNA probe. The Cd-binding protein displayed cross-reactivity in a competitive ELISA with antiserum raised against rainbow trout MT and had the characteristic amino acid composition, metal stoichiometry and spectral characteristics of a Class I MT. Only one isoform was apparent on ion exchange chromatography. Southern blot analysis of DNA cleaved with four restriction enzymes suggested that only a single MT gene is present in turbot.In an established turbot fibroblast cell line, Cd induced MT mRNA and MT levels in a dose and time-dependent manner. MT was also induced by Cu, Hg and Zn but not Pb exposure. Physiological concentrations of glucocorticoids and sex hormones did not induce MT synthesis, although at high concentrations a positive response to corticosterone, dexamethasone, hydrocortisone or progesterone was observedin vitro indicating the possible presence of a functional steroid regulatory element in the fish MT gene.Abbreviations used AMP adenosine monophosphate - CHSE chinook salmon embryo - DMSO dimethyl sulphoxide - HPLC high performance liquid chromatography - KB kenacid blue - MT metallothionein - Mr molecular weight (kDaltons) - NR neutral red - PEG polyethylene glycol - RTH rainbow trout hepatoma - SDS sodium dodecyl sulphate - SSC 0.15M NaCl, 0.015M sodium citrate - TF turbot fibroblast  相似文献   

The mbuna cichlids of Lake Malawi: a model for rapid speciation and adaptive radiation   总被引：6，自引：0，他引：6  

Martin J. Genner  & George F. Turner 《Fish and Fisheries》2005,6(1):1-34

Mbuna, the dominant fishes on the rocky shores of Lake Malawi, have become a major ‘model system’ for the study of rapid speciation and adaptive radiation. At least 295 putative species are known, of which more than 200 remain undescribed. There is no good evidence for monophyly in the mbuna, rather mitochondrial DNA phylogenies indicate that they are polyphlyetic with respect to benthic feeding cichlids of the genera Aulonocara, Alticorpus and some species of Lethrinops. Male mbuna hold territories for 18 months or more and breed year‐round. All species are maternal mouthbrooders, but females do not guard free‐swimming young. Mbuna are polygamous (both sexes). There is sexual dimorphism in size, colour and fin length, and many species show within‐population colour polymorphism. Mbuna genera are largely differentiated on the basis of head, jaw and tooth morphology, but congeneric species are generally distinguished by male colour. Many morphologically specialized forms have broad diets and often feed on common easily obtainable resources. While it is likely that dietary and habitat niche partitioning contributes to species coexistence, this has never clearly been demonstrated under experimental conditions. Populations on spatially separated habitat patches are often genetically differentiated, probably because most species are specialized for life on rocky shores, and lack a dispersal phase in their life histories. Males seem to disperse more than females, but are able to home several kilometres back to their territories. Some closely related ecologically equivalent allopatric populations are differentiated in male colour. Those tested have been shown to mate at least partially assortatively. Sexual selection acting on male colour seems the most plausible mechanism for initial species divergence. The same colour forms seem to have arisen several times, suggesting frequent parallel evolution. The main conservation threat to mbuna at present seems to be translocation of species within the lake as a result of the aquarium trade. However, deleterious effects on indigenous populations are not documented. In the long run, sedimentation, pollution, introduction of alien species and the development of targeted food fisheries could be more serious threats.  相似文献