The effect of temperature on the clearance of intraperitoneally-injected gonadotropin in the goldfish Carassius auratus     

Alan Frank Cook  R.E. Peter 《Aquaculture (Amsterdam, Netherlands)》1980,19(3):275-285

The serum half-disappearance time ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$), metabolic clearance rate and volume of distribution of intraperitoneally administered carp gonadotropin (cGtH) and endogenous GtH levels were determined in sexually mature male and female goldfish, Carassius auratus maintained at 12 ± 1°C or 20 ± 1°C. The results indicated that the rate of serum uptake of the injected cGtH from the peritoneal cavity was greater at 20°C than at 12°C in sexually mature male goldfish. Although increased endogenous serum GtH levels and decreased values of serum $\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ were associated with the elevated temperature, there was no difference in any of the parameters between sexually mature male and female goldfish acclimated to 12°C.  相似文献   

Genetic covariation in production traits of sub-adult black bream Acanthopagrus butcheri after grow-out     

Robert G Doupé  & Alan J Lymbery 《Aquaculture Research》2005,36(11):1128-1132

Predicting the suitability and reliability of traits associated with juvenile growth as indirect selection criteria for choosing future broodstock requires accurate and repeatable estimates of genetic (co)variation for growth traits at different ages. We compared juvenile wet weight of black bream Acanthopagrus butcheri (Munro) at 6 months of age with wet weight, dressed weight, fillet yield and gonad weight in tagged individuals at 18 months of age, following 12 months of farm grow‐out. Fish survival and tag retention was high, and there was significant among‐family variation for all traits. The phenotypic correlations among wet weight, dressed weight and fillet yield at 18 months of age were very high (0.93–0.97) and similar to their genetic correlations (0.96). Importantly, the phenotypic correlations between wet weight at 6 months and wet weight, dressed weight and fillet yield at 18 months were high (0.63–0.65), and so too were their genetic correlations (0.66–0.73), indicating the potential for using wet weight in the hatchery as a selection criterion for improved weight and meat yield of fish at harvest. Gonad weight shared little or no phenotypic or genetic correlation with these other traits, suggesting that selection for faster growing fish will not affect fecundity or sexual maturation rate. It appears, however, that cultured black bream do become sexually mature more rapidly than wild fish, as 78% of all fish harvested in this study had developing or mature gonads, whereas less than 50% of fish in wild populations are reproductively mature by the same age. Precocious sexual development may lead to uncontrolled spawning in grow‐out ponds and a potential loss of selection gains.  相似文献   

Keeping watch on the unwatchable: technological solutions for the problems generated by ecosystem-based management   总被引：2，自引：0，他引：2  

Paul E. McShane  Matt K. Broadhurst  & Alan Williams 《Fish and Fisheries》2007,8(2):153-161

Ecosystem‐based management is an emerging paradigm influencing the management of commercial fisheries. Increasingly, developed nations are adopting explicit legislation and policy governing the assessment and management of their fisheries against criteria of ecological sustainability. Yet the ability to evaluate ecosystem impacts of fisheries is compromised by a general lack of understanding of marine ecosystem function (beyond the population level) and a lack of robust and practical indicators for ecosystem health and management. Recent technological advances can assist in developing criteria, including structural analyses of seafloor communities potentially impacted by fishing gears (e.g. demersal trawling). Similarly, advances in fishing gear technology, including improved selectivity and the development of gears which have a more benign environmental impact, can mitigate some of the ecological impacts of fishing. Such technological advances are summarized in the context of contemporary fisheries management.  相似文献   

The Use of Anglers'Returns in the Estimation of Fishing Success     

Alan Cane 《Aquaculture Research》1980,11(4):145-155

The method of collation of angling results at Ffestiniog fishery is described. Rod averages calculated from returns are always higher than those assessed by the fishery bailiff. Two studies indicated that, although there is no reason to question the veracity of returns, those received represent a sample of anglers which is biased towards the more successful. The care needed in extrapolation from angling returns is emphasized and it is demonstrated that only the bailiff's estimates of fishing success lead to sensible estimates of the seasonal catch.  相似文献   

Tests of Some Batch-Marking Techniques for Rainbow Trout (Salmo gairdneri Richardson)     

Alan Cane 《Aquaculture Research》1981,12(1):1-08

Freeze-branding and tattooing by Panjet were used as techniques for rapid application of batch marks to rainbow trout of stockable size. The subsequent performances of the marks produced were compared. Freeze brands took 2 weeks to become clear and thereafter remained wholly satisfactory for only 1 month. Pigments injected by Panjet were immediately visible but of the dyes tested only Alcian blue remained completely clear after a 3-month trial. These results are contrasted with those of other workers in trials with various species of freshwater fish.  相似文献   

What are the prospects for black bream Acanthopagrus butcheri (Munro) aquaculture in salt‐affected inland Australia?     

Robert G Doupé  Gavin A Sarre  Gavin J Partridge  Alan J Lymbery  & Greg I Jenkins 《Aquaculture Research》2005,36(14):1345-1355

Black bream are a highly regarded sport and table fish, and there has been considerable interest in their aquaculture potential for the salt‐affected agricultural regions of inland southern Australia. In many ways they are an ideal candidate species for inland saline aquaculture because they appear to be very hardy, hatchery techniques are well established for them, and high survival rates have been maintained under a variety of culture conditions and feeding regimes. However, their slow growth rate needs to be increased by at least 33% for black bream to become an economically viable aquaculture species. Growth is amenable to genetic improvement, and sub‐adult growth rate shows moderate heritability and no adverse genetic correlations with other production traits. Nevertheless fillet yield is comparatively low, and in conjunction with unpredictable and early sexual development in culture, industry‐scale meat production remains problematic. These obstacles, however, do not preclude the use of black bream as a recreational fish species for inland saline waters, where their stocking may provide an additional source of rural income and relieve fishing pressure on depleted estuarine populations.  相似文献   

Editorial     

Hugh Dove  Alan Hopkins 《Grass and Forage Science》2014,69(1):1-1

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Marine Pseudovibrio sp. as a Novel Source of Antimicrobials     

Susan P. Crowley  Fergal O’Gara  Orla O’Sullivan  Paul D. Cotter  Alan D. W. Dobson 《Marine drugs》2014,12(12):5916-5929

Antibiotic resistance among pathogenic microorganisms is becoming ever more common. Unfortunately, the development of new antibiotics which may combat resistance has decreased. Recently, however the oceans and the marine animals that reside there have received increased attention as a potential source for natural product discovery. Many marine eukaryotes interact and form close associations with microorganisms that inhabit their surfaces, many of which can inhibit the attachment, growth or survival of competitor species. It is the bioactive compounds responsible for the inhibition that is of interest to researchers on the hunt for novel bioactives. The genus Pseudovibrio has been repeatedly identified from the bacterial communities isolated from marine surfaces. In addition, antimicrobial activity assays have demonstrated significant antimicrobial producing capabilities throughout the genus. This review will describe the potency, spectrum and possible novelty of the compounds produced by these bacteria, while highlighting the capacity for this genus to produce natural antimicrobial compounds which could be employed to control undesirable bacteria in the healthcare and food production sectors.  相似文献   

Fish species redundancy in estuaries: A major conservation concern in temperate estuaries under global change pressures     

Alan K. Whitfield  Trevor D. Harrison 《水产资源保护:海洋与淡水生态系统》2021,31(4):979-983

1. Fish assemblages in estuaries have a much lower species richness (number of taxa) when compared with the combined numbers of freshwater and marine species from adjacent aquatic ecosystems. This is primarily because of the relatively harsh and fluctuating physico-chemical conditions in estuaries compared with the more stable freshwater and marine environments.
2. A comprehensive fish survey of estuaries in South Africa is used as a basis to determine fish species richness in subtropical, warm temperate, and cool temperate systems along the coast, and to assess the degree of redundancy in the different biogeographic regions.
3. In general, only one or two species belonging to each of the detritivorous, piscivorous, zoobenthivorous, and zooplanktivorous fish guilds are numerically well represented in the larger cool temperate estuaries, but between four and 10 species in each of these guilds are usually recorded in the larger subtropical estuaries.
4. Although the overall low redundancy of fish species groups in estuaries has already been formally recognized in the literature, this short note highlights the sensitivity of certain trophic guilds in temperate South African estuaries to any form of redundancy, a characteristic that may be equally applicable, based on declining species richness with increasing latitude, to temperate estuaries in other parts of the world.

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Residential movements of top predators in Chile’s most isolated marine protected area: Implications for the conservation of the Galapagos shark,Carcharhinus galapagensis,and the yellowtail amberjack,Seriola lalandi     

Naití A. Morales  Maike Heidemeyer  Robert Bauer  Sebastian Hernández  Enzo Acuña  Simon Jan van Gennip  Alan M. Friedlander  Carlos F. Gaymer 《水产资源保护:海洋与淡水生态系统》2021,31(2):340-355

1. Marine protected areas (MPAs) are becoming a widely used tool for the conservation of biodiversity and for fishery management; however, most of these areas are designed without prior knowledge of the basic ecological aspects of the species that they are trying to protect.
2. This study investigated the movement of two top predators: the Galapagos shark, Carcharhinus galapagensis, and the yellowtail amberjack, Seriola lalandi, in and around the Motu Motiro Hiva Marine Park (MMHMP) using MiniPAT satellite tags to determine the effectiveness of this MPA for the protection of these species.
3. The Galapagos sharks (n = 4) spent most of their tag deployment periods inside the MMHMP. However, high intraspecific variability was observed in their movement dynamics. Daily individual maximum movements ranged from 17 to 58 km and the maximum distance from Salas y Gómez Island, the only emergent island within the MMHMP, ranged from 31 to 139 km.
4. The maximum linear distance travelled for a female juvenile Galapagos shark (152 cm total length) was 236 km, which is greater than the maximum distance previously documented for juveniles of this species (<50 km).
5. For the yellowtail amberjack (n = 1), 91% of the satellite geolocations were within the MMHMP, with a maximum daily distance travelled of 6 km. The maximum distance travelled between points was 111 km and the maximum distance from Salas y Gómez Island was 62 km.
6. All archival tagged fish spent most of their time at depths of <50 m and never left the epipelagic zone. Daytime versus night-time differences were pronounced in all individuals but showed high interindividual variability.
7. This study provides a baseline on the movement of these two top predators in the MMHMP and provides valuable insights for the creation of MPAs in the region and elsewhere.

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