Myxobolid parasites (Myxozoa: Myxobolidae) infecting fishes of western Montana, with notes on histopathology, seasonality, and intraspecific variation

1989 ◽  
Vol 67 (8) ◽  
pp. 1915-1922 ◽  
Author(s):  
Lawrence G. Mitchell

Cypriniform and salmonid fishes of the Columbia River drainage of western Montana harbor five members of the myxozoan family Myxobolidae. Myxobolus muelleri inhabits Ptychocheilus oregonensis (northern squawfish), Mylocheilus caurinus (peamouth), Richardsonius balteatus (redside shiner), and Catostomus macrocheilus (largescale sucker). Cysts appeared in gills, musculature, subcutis, and visceral mesenteries. Unencysted spores infiltrated mesenteries and viscera. Spore size and shape in the various tissues and hosts were highly varied. Muscle and subcutaneous cysts were associated with connective tissue proliferation and muscle degeneration; cyst rupture was associated with diffuse inflammation and rodlet cell proliferation. Infection prevalence in muscles and kidneys was high in adult and juvenile hosts (78–100%) throughout the year. Seasonal prevalence of gill and subcutaneous infections fluctuated markedly. Cysts of Myxobolus dujardini occurred in gills of the northern squawfish, peamouth, and redside shiner. Unicauda sp. was found in the eye capsule, gall bladder, mesenteries, and kidney of northern squawfish. Henneguya zschokkei occurred in intermuscular connective tissue of Prosopium coulteri (pygmy whitefish) and Prosopium williamsoni (mountain whitefish). Myxobolus sp. occurred in the gills of Catostomus catostomus (longnose sucker).

1953 ◽  
Vol 31 (3) ◽  
pp. 211-225 ◽  
Author(s):  
C. C. Lindsey

Anal fin rays were counted on 4766 specimens of Richardsonius balteatus from 61 localities in British Columbia. Individual counts varied from 10 to 21, and mean counts of different populations varied from 12.06 to 17.51. Significant differences in counts occurred between different bodies of water, between recently introduced populations and their parent stock, between different parts of the same lake, and between different year classes. Ray counts tended to be higher amongst females in populations with high over-all means, and higher amongst males in populations with low over-all means. A positive correlation was demonstrated between water temperatures recorded in the vicinity of developing fry and the mean numbers of anal rays produced. Within each latitudinal zone a similar correlation occurred between mean ray count and average air temperature during the spawning season, but data on 109 means of populations in U.S.A. and Canada indicated a tendency, probably genetic, towards production, at equivalent temperature, of higher ray count towards the northern end of the range. Loose correlations between anal ray count and certain other morphological characteristics suggest that these may be dependent on more or less common environmental factors but are not linked by direct causality.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Marshal S. Hoy ◽  
Carl O. Ostberg

Abstract Objective A quantitative PCR (qPCR) assay for the detection of redside shiner (Richardsonius balteatus) environmental DNA (eDNA) was designed as a side product of a larger project aimed at using eDNA to determine the presence and geographic extent of native and non-native fishes in the reservoirs and associated tributaries above the three mainstem dams (Ross, Diablo, Gorge) on the Skagit River, Washington, USA. The eDNA survey results can be used to help guide additional sampling efforts that include traditional sampling methods, such as electrofishing and netting. Results The redside shiner qPCR assay (RSSCOI_540-601) was validated by testing for sensitivity using redside shiner genomic DNA from three different populations and by testing for specificity against 30 potentially sympatric species. No non-target amplification was observed in our validation tests. We then evaluated the assay on field-collected water samples where there are known populations of redside shiner and a negative control site where the target species is known to be absent. The field-collected water samples tested positive at the redside shiner sites and tested negative at the negative control site. The assay could provide resource managers with an effective means for surveying and monitoring redside shiner populations.


2001 ◽  
Vol 58 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Craig A Tinus ◽  
Gordon H Reeves

We examined the relative effects of zero, three, and nine redside shiner (Richardsonius balteatus) on the aggression-related damage among three juvenile steelhead (Oncorhynchus mykiss) in aquaria at 15 and 20°C. No steelhead died when in the presence of nine redside shiner. When redside shiner were not present, mortality among the smallest steelhead was 80%. Thus, the survival of smaller juvenile steelhead was significantly enhanced by the presence of redside shiner. A second experiment was conducted in 6800-L stream channels at 15°C with natural substrate. In separate trials, 10 and 7 steelhead were held either alone or with 20 redside shiner. In the absence of redside shiner, fin damage was significantly greater among smaller steelhead. In both experiments, if a redside shiner group was present, the smallest steelhead frequently took refuge within the shiner group, thereby avoiding attack by dominant steelhead. We have termed this phenomenon a behavioural competitive refuge.


2012 ◽  
Vol 2 ◽  
pp. 113-120
Author(s):  
Rosaiah Kanaparthy ◽  
Aruna Kanaparthy ◽  
Kamala Devi

1974 ◽  
Vol 31 (4) ◽  
pp. 411-420 ◽  
Author(s):  
Lance W. Steigenberger ◽  
P. A. Larkin

Trapnet catches of northern squawfish (Ptychocheilus oregonensis) at Griffen and Cultus lakes, British Columbia, indicated peak activity and feeding in the twilight and dark hours. At Griffen Lake, squawfish force-fed 2.0 g of redside shiner (Richardsonius balteatus), and held at 17–20 C, digested at a rate of roughly 14%/h. At Cultus Lake, squawfish trapped during the peak of feeding activity, and held at 10–12 C, were sacrificed at 6-h intervals, and showed a digestion rate of sockeye salmon (Oncorhynchus nerka) smolts of 14%/h. Larger fish ate larger volumes of food. Regression techniques are not completely adequate for describing the course of digestion, which apparently involves an initial period of retention of food, followed by a fairly rapid evacuation of most of the ingested material. Most fish cleared their stomach contents in 24 h, and one half had done so between 12 and 18 h. In the laboratory, squawfish force-fed rainbow trout (Salmo gairdneri) had rates of digestion which increased with temperature, from about 5%/h at 4–6 C, to 40–50%/h at 24 C. Larger weights of food were digested at slower rates, but there were no consistent differences in rate of digestion by different sizes of squawfish.The rates of digestion are higher than those reported for various predatory European fishes.


2017 ◽  
Vol 188 (1) ◽  
pp. 155-161
Author(s):  
Maria P. Grushko ◽  
Nadezhda N. Fedorova ◽  
Alina A. Aitimova

Internal organs of black-backed shad are examined by histological analysis. Wide range of pathologies is found, which are supposedly caused by chronic environmental pollution. The pathologies of tissue and cellular levels have common features but various symptoms, as edema, hemorrhage, necrosis, inflammation, connective tissue proliferation, proliferative changes in the epithelium. The gills, liver; kidney, and intestines are the most sensitive to negative impacts of environments.


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