Feeding Activity and Rates of Digestion of Northern Squawfish (Ptychocheilus oregonensis)

1974 ◽  
Vol 31 (4) ◽  
pp. 411-420 ◽  
Author(s):  
Lance W. Steigenberger ◽  
P. A. Larkin
Keyword(s):  
Sockeye Salmon ◽  
Feeding Activity ◽  
Initial Period ◽  
Stomach Contents ◽  
Salmo Gairdneri ◽  
Peak Activity ◽  
Regression Techniques ◽  
Redside Shiner ◽  
Richardsonius Balteatus ◽  
Rapid Evacuation

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.

A Predator–Prey Interaction in Freshwater Fish

1959 ◽  
Vol 16 (3) ◽  
pp. 269-281 ◽  
Author(s):  
E. J. Crossman
Keyword(s):  
Growth Rate ◽  
Rainbow Trout ◽  
Water Temperature ◽  
Freshwater Fish ◽  
Salmo Gairdneri ◽  
Lake Morphometry ◽  
Predator Prey ◽  
Prey Interaction ◽  
Redside Shiner ◽  
Richardsonius Balteatus

The predator–prey interaction of rainbow trout, Salmo gairdneri Richardson, and the redside shiner, Richardsonius balteatus (Richardson), in Paul Lake, British Columbia, depends on such factors as distribution and movements of predator and prey, behaviour of predator and prey, lake morphometry, shoal water temperature and characteristics of the fish.In adult trout, activity associated with predation follows a stereotype pattern. Behaviour may also be responsible for the fact that trout under 10 inches in length do not utilize, as food, even small shiners to any extent, even though under laboratory conditions they will kill and eat them. The estimated annual kill of shiners by predatory trout is 150,000 and the shiner population is probably in the millions. Shiners preyed on are such that predation appears not to limit recruitment to the prey population. Shortly after their introduction to the lake shiners reduced the growth rate of small trout by competition. There is evidence that feeding on shiners now increases the growth rate of at least those trout over 14 inches whose food is as high as 98% shiners in summer.

Competition for Food Between Redside Shiners (Richardsonius balteatus) and Rainbow Trout (Salmo gairdneri) in Two British Columbia Lakes

1961 ◽  
Vol 18 (2) ◽  
pp. 203-220 ◽  
Author(s):  
R. E. Johannes ◽  
P. A. Larkin
Keyword(s):  
British Columbia ◽  
Rainbow Trout ◽  
Interspecific Competition ◽  
Stomach Contents ◽  
Salmo Gairdneri ◽  
Interspecific Aggression ◽  
Large Numbers ◽  
Competition For Food ◽  
Biological Environment ◽  
Richardsonius Balteatus

The distribution, movements, behaviour and food of trout and shiners in Paul and Pinantan Lakes were studied to determine the items and mechanisms of interspecific competition between them. Data from recent years were compared with data for years when trout alone inhabited the lakes.No interspecific aggression was observed. The possibility that the two species were competing for space was discounted. Stomach contents of shiners in Pinantan Lake revealed a marked qualitative diurnal food cycle. In Paul Lake, shiners have drastically reduced the Gammarus population relative to its pre-shiner abundance, forcing trout, as well as the shiners themselves, to shift their diets to other foods. This overgrazing was caused by the concentration of large numbers of shiners over the shoals where Gammarus are also present in their highest concentrations, and the ability of shiners to pursue food deeper into the weeds and to graze an area more thoroughly than trout. In Pinantan Lake, shiners have apparently reduced the density of Daphnia to a point where trout are unable to feed on them as rapidly as in pre-shiner years. The ability of both species to utilize many types of food tends to reduce the intensity of competition.The study demonstrates how false implications may arise from an appraisal of competition not initiated until after the effects of competition have been observed. If observations had not been made on Paul Lake until after competition had been observed, the importance of Gammarus as an item of competition would probably have been overlooked and the whole competitive relationship misconstrued.Environmental factors and behaviour were shown to be important influences on the dynamics of competition. The physical and biological environment and the distribution and behaviour of competitors may be in states of continual flux in which case the niches of the competitors cannot be considered constant.

Interactions Between the Redside Shiner (Richardsonius balteatus) and the Steelhead Trout (Salmo gairdneri) in Western Oregon: The Influence of Water Temperature

1987 ◽  
Vol 44 (9) ◽  
pp. 1603-1613 ◽  
Author(s):  
Gordon H. Reeves ◽  
Fred H. Everest ◽  
James D. Hall
Keyword(s):  
Water Temperature ◽  
Warm Water ◽  
Salmo Gairdneri ◽  
Intermediate Water ◽  
Steelhead Trout ◽  
Cool Water ◽  
Influence Of Water ◽  
Similar Range ◽  
Redside Shiner ◽  
Richardsonius Balteatus

Water temperature influenced interactions between redside shiner (Richardsonius balteatus) and juvenile steelhead trout (Salmo gairdneri) (≥1 +) in the field and laboratory. Trout in cool water when shiner were absent and at intermediate water temperatures with shiner present occupied a similar range of habitats. Shiner alone in warm water occupied habitats similar to trout, but in the presence of trout occupied slower, deeper areas than when alone. In laboratory streams, production by trout was the same in the presence and absence of shiner in cool water (12–15 °C). In warm water (19–22 °C), production by trout decreased by 54% in the presence of shiner compared with when shiner were absent. Production of shiner in cool water decreased in the presence of trout, −0.3 g∙m−2∙d−1 together compared with 0.5 g∙m−2∙d−1 alone, but was not affected by the presence of trout in warm water. Trout distribution was not influenced by shiner in cool waters, but was influenced at warm temperatures. Shiner occupied all areas of the laboratory channels in the absence of trout in cool waters but were restricted to a few pools in the presence of trout. Distribution of shiner was not influenced by trout at warm temperatures.

Food Specialization By Individual Trout

1972 ◽  
Vol 29 (11) ◽  
pp. 1615-1624 ◽  
Author(s):  
James E. Bryan ◽  
P. A. Larkin
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Stomach Contents ◽  
Cutthroat Trout ◽  
Salmo Gairdneri ◽  
Potential Prey ◽  
Repeated Observation ◽  
Size Growth ◽  
Salmo Clarki

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.

Occurrence of the eyefluke, Diplostomum (Diplostomum) baeri bucculentum Dubois et Rausch, 1948, in salmonid fishes of northern British Columbia

1985 ◽  
Vol 63 (2) ◽  
pp. 396-399 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
Rainbow Trout ◽  
Chinook Salmon ◽  
Sockeye Salmon ◽  
Lake Trout ◽  
Infected Fish ◽  
Salmo Gairdneri ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Dolly Varden Salvelinus Malma ◽  
Prosopium Williamsoni

As a result of experimental infections in chicks, diplostomula found in the retina of chinook salmon from the Nechako River were identified as Diplostomum (Diplostomum) baeri bucculentum. Eyeflukes in other salmonids were considered to be the same species based on similar measurements and site in the eyes. These eyeflukes varied in prevalence and mean intensity in seven salmonid species surveyed in nine localities in 1979–1981. The following fish were sampled: rainbow trout (Salmo gairdneri), 505; mountain whitefish (Prosopium williamsoni), 334; lake whitefish (Coregonus clupeaformis), 32; Dolly Varden (Salvelinus malma), 66; lake trout (S. namaycush), 13; kokanee or sockeye salmon (Oncorhynchus nerka), 323; and chinook salmon (O. tshawytscha), 164. Eyeflukes had prevalences ranging from 84 to 100% in six lakes, 64% in the river, 53% in one reservoir site, and a prevalence of 15% in the other reservoir site. Mountain and lake whitefishes had high mean intensities while kokanee had low mean intensities. Correlation of increased intensity with increased fish size was significant for 6 of 27 samples. Four samples of lake whitefish, mountain whitefish, rainbow trout, and chinook salmon showed significant asymmetry when numbers of diplostomula were compared between eyes. More of the heavily infected fish showed asymmetry than did the lightly infected fish.

VARIATION IN ANAL FIN RAY COUNT OF THE REDSIDE SHINER RICHARDSONIUS BALTEATUS (RICHARDSON)

1953 ◽  
Vol 31 (3) ◽  
pp. 211-225 ◽  
Author(s):  
C. C. Lindsey
Keyword(s):  
Morphological Characteristics ◽  
Introduced Populations ◽  
Fin Ray ◽  
Parent Stock ◽  
Different Populations ◽  
The Mean ◽  
Redside Shiner ◽  
Richardsonius Balteatus ◽  
Bodies Of Water ◽  
Different Parts

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.

scholarly journals Diel feeding pattern and diet of rough scad Trachurus lathami Nichols, 1920 (Carangidae) from the Southwestern Atlantic

2006 ◽  
Vol 4 (4) ◽  
pp. 419-426 ◽  
Author(s):  
Maria Raquel de Carvalho ◽  
Lucy Satiko Hashimoto Soares
Keyword(s):  
Feeding Activity ◽  
Stomach Contents ◽  
Feeding Time ◽  
Frequency Of Occurrence ◽  
Southwestern Atlantic ◽  
Calanoid Copepods ◽  
Teleostean Fish ◽  
Dark Cycle ◽  
Percent Number ◽  
Decapod Larvae

Diel changes in feeding activity and dietary composition of the rough scad Trachurus lathami were investigated through the analysis of stomach contents of 307 fish sampled over a 24-h period on the continental shelf off Ubatuba (23º 35'S 45ºW). Stomach contents were analyzed by frequency of occurrence (O%), percent number (N%), percent mass (M%), and feeding index (FI% = O% * M%). Rough scad fed on mollusks (Gastropoda, Crepidula sp.), crustacean (Ostracoda, Copepoda, decapod larvae), chaetognat and teleostean fish. The main items were calanoid copepods (Eucalanus sp. and Centropages sp.). According to the analysis of the stomach fullness and prey digestion, T. lathami is both a diurnal and nocturnal feeder, showing some seasonal variation in feeding time. According to the Chronobiology concept, it was raised the hypothesis of circadian rhythm in feeding of this fish, probably synchronized by light/dark cycle.

scholarly journals Variations of Salminus hilarii diet (Ostariophysi, Characidae): seasonal and ontogenetic effects

2015 ◽  
Vol 75 (3) ◽  
pp. 574-580
Author(s):  
GA Villares Junior ◽  
R Goitein
Keyword(s):  
Prey Size ◽  
Pearson Correlation ◽  
Feeding Activity ◽  
Stomach Contents ◽  
Food Composition ◽  
Spearman Correlation ◽  
Statistical Comparison ◽  
Significant Difference ◽  
Ontogenetic Effects ◽  
Size And Morphology

AbstractThis study described the variations seasonal and ontogenetic of Salminus hilarii diet. Samples were collected in the Sorocaba River, São Paulo, Brazil, one of the few rivers where individuals of the species still occur in a higher frequency. The preys consumed were analyzed by Importance Alimentary Index (AIi). To determine similarities between year seasons, the AIi data were analyzed by the Morisita-Horn index and reduced in cluster analysis, along with a statistical comparison made by one-way ANOSIM test (5%). The feeding activity was analyzed according to the stomach repletion index and compared among the year seasons using non parametric variance analysis Kruskal-Wallis test (5%). Comparison of prey consumed between immature and adult individuals was made by Spearman correlation (5%). A Pearson correlation (5%) was applied between the standard length of the fish and prey consumed, as well as between the mouth and prey heights. The analyzes of stomach contents showed that the diet of this species was exclusively piscivorous, with significant difference of prey consumption during the period, the same happening among adult and immature individuals. It was observed that these fishes use to swallow their prey whole and that significant correlations between size of predator and prey size can be observed. There is also correlation between the mouth height and the maximum prey depth. Salminus hilarii feeds on the available prey, and the species food composition and feeding activity depends on prey`s abundance, their size and morphology, as do the water temperatures.

scholarly journals Development of a quantitative PCR assay for detection of redside shiner (Richardsonius balteatus) from environmental DNA

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Marshal S. Hoy ◽  
Carl O. Ostberg
Keyword(s):  
Quantitative Pcr ◽  
Water Samples ◽  
Effective Means ◽  
Environmental Dna ◽  
Sympatric Species ◽  
Negative Control ◽  
Control Site ◽  
Qpcr Assay ◽  
Redside Shiner ◽  
Richardsonius Balteatus

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.

Redside shiner (Richardsonius balteatus) shoals provide a behavioral competitive refuge for subordinate juvenile steelhead trout (Oncorhynchus mykiss)

2001 ◽  
Vol 58 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Craig A Tinus ◽  
Gordon H Reeves
Keyword(s):  
Oncorhynchus Mykiss ◽  
Steelhead Trout ◽  
Natural Substrate ◽  
Stream Channels ◽  
Redside Shiner ◽  
Richardsonius Balteatus

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.

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