Glochidial infestation of fish by the endangered thick‐shelled river mussel Unio crassus          下载免费PDF全文

Adam M. Ćmiel  Katarzyna Zając  Anna M. Lipińska  Tadeusz Zając 《水产资源保护:海洋与淡水生态系统》2018,28(3):535-544

Aphanomyces astaci presence in Japan: a threat to the endemic and endangered crayfish species Cambaroides japonicus?          下载免费PDF全文

Agata Mrugała  Tadashi Kawai  Eva Kozubíková‐Balcarová  Adam Petrusek 《水产资源保护:海洋与淡水生态系统》2017,27(1):103-114

Comparative survival and growth performance of European lobster larvae,Homarus gammarus,reared on dry feed and conspecifics          下载免费PDF全文

Adam Powell  James Hinchcliffe  Kristina Sundell  Nils‐Gunnar Carlsson  Susanne P. Eriksson 《Aquaculture Research》2017,48(10):5300-5310

A bottleneck of crustacean larval culture concerns nutrition and associated cannibalism in communal rearing systems, which impact on larval survival, development and growth. For early‐stage European lobster, Homarus gammarus larvae, feeding ecology and body composition are largely unknown. We initiated four progressive feeding experiments (novel feed types, feeding regime and feed size and cannibalism effects) on growth and survival, to inform and update husbandry protocols. Performance of larvae offered a dry commercial feed was not significantly different compared with a conventional wet plankton feed of the same ration and size grade (both within 600–1,000 μm). Further experiments found that the same ration of dry feed offered six times daily improved development and growth, over the conventional regime of three times daily. Small‐grade dry feed (particles: 250–360 μm) improved larval performance compared with a larger feed (360–650 μm). Larvae were also fed different proportions of dry feed and/or conspecifics in both communal and individual rearing systems (the latter preventing cannibalism via segregation). Individually reared larvae, fed only dead conspecifics, displayed the greatest survival (80%) to postlarvae. This underlines the impact of cannibalism on survival and nutrition in H. gammarus larviculture. A final experiment analysed H. gammarus zoea 1 composition, identifying deficiencies in ash and carbohydrate in lobster feeds. This suggests a need for a species‐specific, formulated dry feed for H. gammarus larviculture. Our research represents the first investigation of H. gammarus larval composition and dietary requirements and highlights decreased growth potential associated with providing nutrition solely from generic commercial feed.  相似文献   

Virucidal effects of various agents—including protease—against koi herpesvirus and viral haemorrhagic septicaemia virus     

Anette Amtmann  Ibrahim Ahmed  Petra Zahner-Rimmel  Adam Mletzko  Lisa Katharina Jordan  Martin Oberle  Helmut Wedekind  Jürgen Christian  Sven Michael Bergmann  Anna Maria Becker 《Journal of fish diseases》2020,43(2):185-195

In a search for alternative, environmentally friendly and effective disinfecting agents, a commercially available protease—Neutrase^®—was tested in this work for inactivation of koi herpesvirus (KHV) and of viral haemorrhagic septicaemia virus (VHSV). For comparison, the stability of these viral pathogens in similar configurations at various pH values and concentrations of peracetic acid or quicklime, typically used for disinfection, was tested. Therefore, virus suspensions were incubated with various concentrations of different agents for 24 hr and the titre of the remaining infectious particles was determined by virus titration. Furthermore, the treatment of both viruses, with the agents at concentrations that were previously appointed as effective, was also examined in the presence of solid material (quartz sand). All procedures investigated in this study, including the protease treatment, were able to reduce the titre of KHV and VHSV below the detection limit of the titration. Although further studies are necessary, this is the first report of the application of a protease for the inactivation of the selected fish pathogens, demonstrating the great potential of the latter for disinfection.  相似文献   

Comparative survival and growth performance of European lobster Homarus gammarus post‐larva reared on novel feeds     

James Hinchcliffe  Adam Powell  Markus Langeland  Aleksandar Vidakovic  Ingrid Undeland  Kristina Sundell  Susanne P. Eriksson 《Aquaculture Research》2020,51(1):102-113

One approach to ongrow juvenile European lobster, Homarus gammarus, is to utilize land based rearing systems, incorporating automated feeding, individual culture and provision of stable pelleted feeds, preferably using sustainable ingredients. We initiated three feeding experiments to investigate the general suitability of ingredients produced from seafood by‐products as novel feeds for H. gammarus, in terms of promoting survival, development and growth of post‐larval lobsters from post‐larvae (PL) stage IV to the first juvenile stage (stage V). The first experiment was designed to screen an array of candidate, locally produced, novel protein sources on growth performance parameters. This initial experiment revealed that PL reared on a raw (i.e. wet, unprocessed shrimp) feed used as a reference showed superior performance to those reared on experimental feeds containing fishmeal, herring protein isolate or mussel meal; however, a novel type of shrimp meal, produced by flocculation from waste water, promoted the best PL performance of any experimental feed. A second experiment was designed to test the effect of drying method and to optimize the form of a wet shrimp reference feed used by lobster hatcheries. This showed that the performance of PL reared on experimental freeze‐dried shrimp feed was not significantly different to those reared on the wet, unprocessed shrimp used as a reference feed. However, lobsters offered experimental oven‐dried shrimp feed (with or without an immune supplement) resulted in significantly lower survival or growth performance. A third and final experiment was designed in an attempt to improve a candidate herring‐based protein source, by supplementing with nutrients found in shrimp. However, the results showed that PL reared on the wet reference shrimp feed still showed superior growth and survival than those reared on a herring feed alone, or supplemented with additives found in shrimp meal (either glucosamine, astaxanthin or both supplements combined). The high survival and growth, low incidence of moulting problems and high availability of waste shrimp material, suggest that non‐heat‐treated shrimp products are a promising feed ingredient for post‐larval European lobsters.  相似文献   

Do active‐dispersing insects dominate the invertebrate fauna of rock pools in the wet–dry tropics,Kimberley, Australia?     

Nicole Carey  Adam T. Cross  Matthew D. Barrett  Belinda J. Robson 《水产资源保护:海洋与淡水生态系统》2019,29(8):1175-1189

Response of Scotian Shelf silver hake (Merluccius bilinearis) to environmental variability     

Daniel Reed  Stphane Plourde  Adam Cook  Pierre Pepin  Benoit Casault  Caroline Lehoux  Catherine Johnson 《Fisheries Oceanography》2019,28(3):256-272

Commercially‐exploited fish populations are not only shaped by fishing pressure, but also by the dynamics of their environment. By quantifying the influence of environmental variability, fisheries management advice can be improved and uncertainties reduced. To this end, we developed statistical models of the response of Scotian Shelf silver hake stock metrics to variability in zooplankton community composition and phenology over the past 18 years and in the physical environment since 1985. Dominant modes of variability in these pelagic habitat indicators were characterized using principal component analysis, and the relationships of silver hake condition, abundance, and recruitment to pelagic habitat variability were assessed using generalized additive models. Condition was largely modulated by the onset and duration of the spring bloom, which controls food availability. In contrast, adult abundance was governed by composition of the zooplankton community and bottom‐water temperature, which dictates the distribution of silver hake. Finally, recruitment was affected by both thermal conditions and food availability. Our results presented here form the basis for qualitative assessment of ecosystem attributes and the influence on silver hake stock productivity.  相似文献   

Energy dynamics of subyearling Chinook salmon reveal the importance of piscivory to short‐term growth during early marine residence     

Marisa N. C. Litz  Jessica A. Miller  Richard D. Brodeur  Elizabeth A. Daly  Laurie A. Weitkamp  Adam G. Hansen  Andrew M. Claiborne 《Fisheries Oceanography》2019,28(3):273-290

Variation in prey quantity and quality can influence growth and survival of marine predators, including anadromous fish that migrate from freshwater systems. The objective of this study was to examine the energy dynamics of subyearling Chinook salmon (Oncorhynchus tshawytscha) following freshwater emigration. To address this objective, a population of Chinook salmon and their marine prey were repeatedly sampled from June to September over 2 years in coastal waters off Oregon and Washington. Subyearlings from the same population were also reared under laboratory conditions. Using a bioenergetics model evaluated in the laboratory, we found that growth rate variability in the field was associated more with differences in northern anchovy (Engraulis mordax) consumption and less with variation in diet energy density or ocean temperature. Highest growth rates (2.43–3.22% body weight/day) occurred in months when anchovy biomass peaked, and the timing of peak anchovy biomass varied by year. Our results support a general pattern among subyearling Chinook salmon occurring from Alaska to California that feeding rates contribute most to growth rate variability during early marine residence, although dominant prey types can differ seasonally, annually, or by ecosystem. In the northern California Current, faster growth appears to be associated with the availability of age‐0 anchovy. Identifying factors that influence the seasonal development of the prey field and regulate prey quantity and quality will improve understanding of salmon growth and survival during early marine residence.  相似文献   

Identifying barriers and motivators for adoption of multifunctional perennial cropping systems by landowners in the Upper Sangamon River Watershed,Illinois     

Chloe M. Mattia  Sarah Taylor Lovell  Adam Davis 《Agroforestry Systems》2018,92(5):1155-1169

The demand on agriculture to meet food security goals and mitigate environmental impacts requires multifunctional land-use strategies. Considering both farmer motivations and rural development needs, one option is to transition marginal farmland to perennial crops. In this study, we considered the potential for Multifunctional Perennial Cropping Systems (MPCs) that would simultaneously provide production and ecosystem service benefits. We examined adoption potential of MPCs on marginal farmland through an agricultural landowner survey in the Upper Sangamon River Watershed in Illinois, USA. We identified adoption preferences among landowners in conjunction with socio-demographic characteristics that would facilitate targeted implementation. Hierarchical cluster analysis and discriminant analysis identified landowner categories and key factors affecting adoption potential. Landowner age, appreciation for plant diversity, and future farm management involvement were the strongest predictors of potential MPCs adoption. The landowner categories identified within the survey data, supplemented with focus group discussions, suggested a high adoption potential farmer profile as a young, educated landowner with known marginal land they would consider converting to MPCs for improved soil and water quality conservation.  相似文献   

Limited fitness costs of herbicide‐resistance traits in Amaranthus tuberculatus facilitate resistance evolution          下载免费PDF全文

Chenxi Wu  Adam S Davis  Patrick J Tranel 《Pest management science》2018,74(2):293-301

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