Effect of spatio‐temporal variables, host fish species and on‐farm biosecurity measures on the prevalence of potentially pathogenic Aeromonas species in freshwater fish farms

Author(s):  
Chandra Bhushan Kumar ◽  
Anil Kumar ◽  
Anutosh Paria ◽  
Saurav Kumar ◽  
K. Pani Prasad ◽  
...  
Author(s):  
Lígia Rigôr Neves ◽  
Luís Mauricio Abdon Silva ◽  
Alexandro Cezar Florentino ◽  
Marcos Tavares-Dias

Abstract This study used information about Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas & Pereira, 1928 that had been published over a period of more than 90 years to investigate the infection and distribution patterns of this nematode in teleost freshwater fish in Brazil. This study was carried out using 181 samples from 82 fish species in 19 families within the five orders, with predominance of Characiformes species (71.6%). We organized a matrix-based parasite-host system in which the fish species were classified in different trophic levels and parasitic infection parameters according data available on host fish species with different life histories and geographic distributions across Brazilian hydrographic basins. Procamallanus (S.) inopinatus showed prevalence ranging from low to moderate, low abundance, low intensity, typically aggregated dispersion, and preferential infection of the hosts' gastrointestinal tract. There was difference in prevalence between detritivorous, omnivorous, carnivorous and piscivorous hosts, but no difference in intensity and abundance was found due to similarity in the communities of this endoparasite among the host fish species. The geographic distribution of this parasite encompasses the river of the Amazon, Paraná, São Francisco, North Atlantic, South Atlantic and Eastern basins. Lastly, suggestions regarding the life cycle of P. (S.) inopinatus, with its potential intermediate hosts, were discussed.


2024 ◽  
Vol 84 ◽  
Author(s):  
M. Bilal ◽  
F. Abbas ◽  
U. Atique ◽  
M. Hafeez-ur Rehman ◽  
M. Inayat ◽  
...  

Abstract Reports abound on Lernaea parasitizing the brood stock, fingerlings, and marketable-sized culturable freshwater fish species in various parts of the world. We investigated seven small-scale aquaculture farms and how the prevailing Lernaea is impacting them. Randomly seven fish farms were selected to determine the prevalence percentage of lernaeid ectoparasites. Relevant information of the fishponds to estimate the various aspects such as effects of water source and quality, feed, stocking density, treatment used, and weight and length of fish, concerned with Lernaea infestation and prevalence was gathered. The results indicated that Catla catla (F. Hamilton, 1822) showed highest prevalence (41.7%) among the seven fish species, whereas Oreochromis niloticus showed zero. Other five fish species Ctenopharyngodon idella, Cirrhinus cirrhosis, Cyprinus carpio, Labeo rohita and Hypophthalmichthys molitrix showed 13.2%, 8.1%, 7.7%, 7.4%, 0.9% prevalence, respectively. In Royal Fish Farm 84.3% lernaeid infestation was observed, while no parasite was observed in the Vicent’s Chunnian fish farm. The water source, quality, feed, fertilizers, stocking density, water temperature, and potential treatment options displayed varying tendencies among fish farms and prevalence. Depending on the weight and length, the highest prevalence (56.7%, and 66.7%) was observed in 3501-4000 g and 81-90 cm groups. The infestation rate varied in various fish body parts with the dorsal fin the most vulnerable organ and showed 2.3% overall prevalence (while 18.4% contribution within total 12.6% infestation). Out of 147 infected fish samples, 45 were extensively contaminated by Lernaea spread. In conclusion, our findings confirm that Lernaea could pose a considerable threat to marketable fish, and various treatment options should be educated to the farmers to help mitigate the spread and potential losses. Furthermore, Catla catla is more vulnerable to Lernaea infestation (41.7%), so are the fish species being cultured at higher stocking densities.


2020 ◽  
Vol 8 ◽  
pp. 39-52
Author(s):  
Kumar Khatri ◽  
Bibhuti Ranjan Jha ◽  
Smriti Gurung ◽  
Udhab Raj Khadka

This review describes the current status of freshwater fish diversity, their IUCN categories and threats to fish fauna in Nepal. The freshwater systems of the country are known to harbor over 220 fish species, thereby indicating a rich ichthyofaunal diversity. However, this number varies from author to author. Cyprinidae is the most common and dominant taxon. A total of 15 endemic and 15 exotic fish species have been reported. A total of 34 fish species have been listed under the IUCN Red List threatened categories. Major threats to fish include damming and pollution. Fish diversity studies have mainly focused on inventories only. Studies focusing on river longitudinal aspects, the inclusion of spatio-temporal aspects, and rigorous taxonomic studies combined with genetic studies are crucial to develop strategic conservation measures of fish fauna in Nepal.


1995 ◽  
Vol 31 (10) ◽  
pp. 73-84 ◽  
Author(s):  
T. M. Iversen

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.


Author(s):  
Felicity Lord ◽  
David B Pyne ◽  
Marijke Welvaert ◽  
Jocelyn K Mara

Field hockey is an evolving sport, but it is unclear whether performance analysis techniques are reflective of current best practice. The objective of this review was to identify performance analysis methods used in field hockey, assess their practicality, and provide recommendations on their implementation in the field. A systematic search of the databases SPORTDiscus, Web of Science, Scopus, MEDLINE and PubMed was performed. Key words addressed performance analysis methods and field hockey, with all other disciplines of sport science excluded. A total of 8 articles were identified from the systematic review. Three studies explored patterns of play in relation to goal scoring opportunities, two articles examined penalty corner strategies and three compared specific actions in hockey. The limited performance analysis research in field hockey has focused on game actions in patterns of play. However, greater insights may be gained by analysing hockey using a holistic approach that incorporates spatio-temporal variables and player-opposition interactions. There is an opportunity to employ novel performance analysis techniques in hockey which provide more practical and effective approaches for analysing strategies and tactics.


Author(s):  
Sam Wenaas Perrin ◽  
Kim Magnus Bærum ◽  
Ingeborg Palm Helland ◽  
Anders Gravbrøt Finstad

Author(s):  
Maria João Costa ◽  
Gonçalo Duarte ◽  
Pedro Segurado ◽  
Paulo Branco

Author(s):  
C.J. Barrett ◽  
M.L. Johnson ◽  
S.L. Hull

The shanny/common blenny (Lipophrys pholis) and long-spined scorpionfish/bullhead (Taurulus bubalis) are commonly encountered, sympatric species within much of Great Britain's rocky intertidal zones. Despite being prey items of the cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) respectively, and both contributors to the diet of the near-threatened European otter (Lutra lutra), little is known on the population dynamics of the temperate specimens of Great Britain. It is further less known of the degrees of sympatricity between the two fish species and to what extent they are able to coexist. The current study examines spatio-temporal distributions and abundances at various resolutions: monthly population dynamics of both species along England's Yorkshire coast and seasonal population dynamics along the Yorkshire coast and around the Isle of Anglesey, Wales. Studies of their abundances, sizes, degrees of rock pool co-occurrence and diel activities are further examined, which indicate coexistence is maintained when interspecific co-occurrence takes place only between specimens of similar sizes, thus demoting size-related dominance hierarchies.


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