94,716 research outputs found
Effect of water temperature and flow rate on the transmission of microsporidial gill disease caused by Loma salmonae in rainbow trout Oncorhynchus mykiss
No full textTwo studies were designed to quantify the effect of water temperature and flow rate on the transmission potential of the important salmonid gill pathogen, Loma salmonae. Using survival analysis, increased water temperature and low flow rates were determined as risk factors for the transmission of microsporidial gill disease caused by L. salmonae in rainbow trout Oncorhynchus mykiss. Fish were experimentally infected with L. salmonae via a cohabitation exposure model and monitored for the development of branchial xenomas. On any given day, fish held at 11degreesC and 15degreesC had a hazard ratio equal to 0.80 and 0.68, respectively, for the development of branchial xenomas compared with fish held at 19degreesC. From the flow rate trial, fish housed in a low flow tank (0.83 L/min) had an increased chance of developing branchial xenomas when compared to fish in tanks at normal (1.67 L/min) and high (2.5 L/min) flow rates with hazard ratios reported as 0.69.PT: J; CR: BARKER DE, 2000, AQUACULTURE, V187, P261 BEAMAN HJ, 1998, THESIS U PRINCE EDWA BEAMAN HJ, 1999, J AQUAT ANIM HEALTH, V11, P237 BEBAKWILLIAMS J, 2002, J FISH DIS, V25, P715 BECKER JA, 2002, J FISH DIS, V25, P673 BODENSTEINER LR, 2000, J AQUAT ANIM HEALTH, V12, P209 CLEVES MA, 2002, INTRO SURVIVAL ANAL GEORGIADIS MP, 2001, PREV VET MED, V48, P287 GUTIERREZ RG, 2002, STATA J, V1, P22 HEDRICK RP, 1998, J AQUAT ANIM HEALTH, V10, P107 KENT ML, 1995, CAN VET J, V36, P98 KLEINBAUM DG, 1986, SURVIVAL ANAL SELF L, P4 MAGOR BG, 1987, CAN J ZOOL, V65, P751 PENNELL W, 1996, PRINCIPLES SALMONID RAMSAY JM, 2001, J FISH DIS, V24, P453 RENO PW, 1998, J AQUAT ANIM HEALTH, V10, P160 ROSS RM, 1995, AQUACULT ENG, V14, P29 SEDGWICK SD, 1990, TROUT FARMING HDB SHAW RW, 1998, DIS AQUAT ORGAN, V33, P151 SHAW RW, 2000, DIS AQUAT ORGAN, V43, P49 SPEARE DJ, 1998, CONTEMP TOP LAB ANIM, V37, P55 SPEARE DJ, 1998, J FISH DIS, V21, P345 SPEARE DJ, 1998, J FISH DIS, V21, P93 SPEARE DJ, 1999, J FISH DIS, V22, P277; NR: 24; TC: 6; J9: FISH PATHOL; PG: 8; GA: 815FNSource type: Electronic(1
Quantitative estimates of fish abundance from boat electrofishing
No full textMultiple removals by boat electro-fishing were used to estimate fish populations in non-wadeable habitats in New Zealand lakes and rivers. Mean capture probability was 0.47±h0.10 (± 95% CI) from 35 population estimates made with 2-7 successive removals. The relationship between the population estimate from the Zippin method (Y)and the number of fish caught in the first removal (X) was significant (adjusted r2=0.84, P<0.001; Figure 2). The least-squares regression was Y = 1.55X 1.23. Mean density ± 95% confidence interval for 13 fishing occasions was 30±27 fish 100 m-
2. Mean biomass of fish for sites was 78±39 g m-2 (range 29 to 245 g m-2). Koi carp comprised the largest proportion of the fish biomass wherever they were present. The high biomasses of koi carp estimated in these results (mean 56±33 g m-2) suggest that they can reach problematic abundances in New Zealand. Bioniass of spawning koi carp can exceed 400 g m-2
Adult status in Trapper Creek and thermal and physical habitat suitability in 2016
Get PDFSteven J. Starcevich, Elizabeth J. Bailey, and Michael H. Meeuwig (Oregon Department of Fish and Wildlife - Native Fish Investigations Program).This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 30-33).Mode of access: Internet from the Oregon Government Publications Collection.Text in English
Repopulation of a coastal stream by brook trout and rainbow-trout after endosulfan poisoning
No full textPT: J; CR: BERGER BL, CITED INDIRECTLY GUNNING GE, 1968, PROG FISH CULT, V30, P92 OLMSTED LL, 1974, T AM FISH SOC, V103, P79 PETERSON RH, 1975, J FISH RES BOARD CAN, V31, P1757 PHILLIPS WEJ, 1965, ENDOSULFAN ITS EFFEC PHILLIPS WEJ, 1975, 14098 NAT RES COUNC RICKER WE, 1968, IBP3 INT BIOL PROGR SCHOETTGER RA, 1970, BUR SPORT FISH WILDL, V35, P1 SMITH MW, 1958, J FISH RES BOARD CAN, V15, P1403 SMITH MW, 1963, J FISH RES BOARD CAN, V20, P327; NR: 10; TC: 3; J9: PROGR FISH-CULT; PG: 4; GA: JS849Source type: Electronic(1
fish and fishery products microbiology bacteria causing fish spoilage
Get PDFThis material describe bacteria which causing spoilage in fish and seafood products
Identification and distribution of fish and shellfish in Tillamook Bay, Oregon: annual report, February 1, 1974 to June 30, 1974
No full textBrent O. Forsberg, Fish Commission of Oregon, in cooperation with Bureau of Sportfisheries and Wildlife, Fish and Wildlife Service, U.S. Department of Interior.This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Electronic reproduction. Salem, Or. : State Library of Oregon, 2021 Electronic reproduction from print version OrMode of access: Internet from the Oregon Government Publications Collection.Text in English
Changes in smooth muscle contractility of rainbow trout (Oncorhynchus mykiss Walbaum) intestine during acclimation to altered temperature
No full textThe effects of altered water temperature in vivo on in vitro smooth muscle contractility of rainbow trout intestine were investigated. Temperature has a significant effect on receptor-mediated intestinal smooth muscle contractility in the rainbow trout. The efficacy of 5-HT, carbachol, and transmural stimulation increased with temperatures above 10-degrees-C, with an optimal increase at 15-degrees-C. There was also a modest increase in the potency of 5-HT and carbachol within 2 days of establishing trout at 20-degrees-C. By day 8, most of these changes had either stabilized or were returning to control values, suggesting that acclimation changes in membranes and enzyme activities were taking effect. However, the contractile responses to carbachol and transmural stimulation were still increasing at this time. This may imply that the muscarinic receptors are more resistant to membrane acclimation changes and may take longer to adapt. Because these experiments were controlled for handling stress and seasonal changes that affect contractility, we have been able to demonstrate some early changes in smooth muscle contractility that occur during acclimation to altered temperature.PT: J; CR: ALOIA RC, 1989, BIOCHIM BIOPHYS ACTA, V988, P123 BRINK C, 1981, J PHARMACOL EXP THER, V217, P592 BURKA JF, 1989, CAN J PHYSIOL PHARM, V67, P477 BURKA JF, 1990, CAN J PHYSIOL PHARM, V68, P700 BURKA JF, 1993, FISH PHYSIOL BIOCHEM, V12, P53 BURNSTOCK G, 1959, Q J MICROSC SCI, V100, P199 CARPENTER JR, 1986, J PHARMACOL METHOD, V15, P283 DEAN JM, 1969, COMP BIOCHEM PHYSIOL, V29, P185 GUDERLEY H, 1992, FISH PHYSIOL BIOCHEM, V10, P123 HAZEL JR, 1992, J COMP PHYSIOL B, V162, P593 HOCHACHKA PW, 1984, BIOCH ADAPTATION HOLMGREN S, 1985, NEUROSCIENCE, V14, P683 JENSEN J, 1991, GEN COMP ENDOCR, V83, P388 KITAZAWA T, 1989, BRIT J PHARMACOL, V98, P781 MCCAULEY RW, 1974, T AM FISH SOC, V106, P362 PICKERING AD, 1982, J FISH BIOL, V20, P229; NR: 16; TC: 1; J9: FISH PHYSIOL BIOCHEM; PG: 9; GA: MP851Source type: Electronic(1
Fixation of mucus on rainbow trout (Oncorhynchus mykiss Walbaum) gills for light and electron microscopy
No full textPT: J; CR: BOLLARD JE, 1986, DIGEST DIS SCI, V31, P1338 BOYD RB, 1980, CELL TISSUE RES, V213, P361 CACECI T, 1984, J FISH BIOL, V25, P1 CORNISH J, 1987, BRIT J EXP PATHOL, V68, P369 FERGUSON HW, 1989, SYSTEMATIC PATHOLOGY, P11 GAIL DB, 1983, AM REV RESPIR DIS, V127, P366 GARLAND CD, 1979, J MICROSC, V116, P227 HANDY RD, 1991, J FISH BIOL, V38, P153 HOSSLER FE, 1986, J SUBMICR CYTOL PATH, V18, P519 HUGHES GM, 1979, J ZOOLOGY LONDON, V187, P443 HUMBERT W, 1984, J FISH BIOL, V25, P117 ICHIKAWA M, 1987, J ELECTRON MICROSC, V36, P117 KENDALL MW, 1979, J FISH RES BOARD CAN, V36, P1072 LUCHTEL DL, 1978, SCANNING ELECT MICRO, V11, P1089 OSTLAND VE, 1990, DIS AQUAT ORGAN, V9, P5 PICKERING AD, 1974, J FISH BIOL, V6, P111 PIIPER J, 1986, J EXP BIOL, V126, P499 ROZEE KR, 1982, APPL ENVIRON MICROB, V43, P1451 SIMS DE, 1991, BIOTECH HISTOCHEM, V66, P173 SPEARE DJ, 1991, J FISH DIS, V14, P21 SPEARE DJ, 1992, IN PRESS J COMP PATH SUMMERFELT RC, 1990, METHODS FISH BIOL, P213 THURSTON RJ, 1976, J ULTRASTRUCT RES, V56, P39 TURNER CR, 1990, STAIN TECHNOL, V65, P95 WHITEAR M, 1984, J FISH BIOL, V25, P317 WRIGHT PA, 1989, J COMP PHYSIOL B, V158, P627; NR: 26; TC: 14; J9: J FISH BIOL; PG: 12; GA: JY797Source type: Electronic(1
Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) – implications for incipient speciation in island freshwater fish species
Get PDFBackground: Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species.
Results: Microchemical analyses of otolith isotopes (Sr-88, Ba-137 and Ca-43) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes.
Conclusion: This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology, spawning timing, population genetics) yield congruent results, and provide clear and independent evidence for the existence of distinct migratory and non-migratory ecotypes within a river in a geographically confined range. The morphological changes within the non-migratory populations parallel interspecific patterns observed in all non-migratory New Zealand endemic Gobiomorphus species and other derived gobiid taxa, a pattern suggesting parallel evolution. This study indicates, for the first time, that distinct ecotypes of island freshwater fish species may be formed as a consequence of loss of migration and subsequent diversification. Therefore, if reproductive isolation persists, these processes may provide a mechanism to facilitate speciation
Combinatorial effects of administration of immunostimulatory compounds in feed and follow-up administration of triple-dose SLICE® (emamectin benzoate) on Atlantic salmon, Salmo salar L., infection with Lepeophtheirus salmonis
No full textSeveral immunostimulatory feed additives have shown the ability to induce protective responses in Atlantic salmon to infection with Lepeophtheirus salmonis. However, even the most encouraging results rarely surpass a 50% protective index in the host. That fact coupled with the well-documented limitations of single-therapy strategies in the effective management of parasitic infections generally make it imperative to identify therapies that can be combined in an integrated pest management approach for sea lice. With this in mind, we hypothesized that immunostimulatory feeds could enhance the protection provided by SLICE® emamectin benzoate (EMB). To test this hypothesis, Atlantic salmon were fed one of two different immunostimulatory feeds (CpG ODN or Aquate®) for c. 7 weeks, challenged with L. salmonis copepodids early within that immunostimulatory feed period and then placed on a triple-dose (150 μg kg(-1) ) feed of SLICE® for 1 week following the completion of the immunostimulatory feeding period. CpG ODN (2 mg kg(-1) ) and the commercial yeast extract (Aquate® 0.2%) inclusion in feeds were able to successfully induce inflammatory gene expression (interleukin-1β) in the head kidneys of infected fish at 13 and 26 days post-exposure (DPE), and 13 DPE, respectively. Lice burdens were lower on fish fed CpG ODN (18%) or Aquate® (19%) diets; however, due to variability, these were not statistically significant over time. Despite no statistically significant reductions in lice numbers, by 33 DPE fish on immunostimulatory feeds had significantly reduced cortisol levels when compared to infected fish on control diet. Cortisol levels in fish receiving an immunostimulatory diet were no different from initial baseline levels prior to infection, whereas the levels in control diet fish were significantly elevated from all other time points. Despite the positive effects on infection of fish fed immunostimulatory feeds, no synergism was observed with follow-up treatment with SLICE® . In fact, highest survival of lice was observed in fish with prior immunostimulation
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