Daily Ration of Yellow Perch (Perca flavescens) from Lake Memphremagog, Quebec–Vermont, with a Comparison of Methods for In Situ Determinations

1978 ◽  
Vol 35 (12) ◽  
pp. 1597-1603 ◽  
Author(s):  
Brian S. Nakashima ◽  
William C. Leggett

In situ estimates of daily ration for yellow perch (Perca flavescens) range from a high of 5.5–6.7% body weight in July to a low of 2.2–2.4% body weight in October. The seasonal pattern corresponds well to known patterns of growth. Comparison of three methods for in situ determination of daily ration levels indicated the method outlined here and the more complex method of Thorpe yield similar results. The method of Keast and Welsh and derivatives of this method which correct for digestion between sampling periods give unreliable values that are 50% below the other two and, in general, are below maintenance ration levels. Diet composition and feeding activity varied seasonally and with body size. Key words: body size relationships, diet composition, seasonality

1988 ◽  
Vol 45 (1) ◽  
pp. 138-145 ◽  
Author(s):  
D. Boisclair ◽  
W. C. Leggett

We compared estimates of daily ration developed using the theoretically rigorous and logistically demanding Elliott and Persson model and the more easily applied Eggers model which is infrequently used because of its assumptions about rigid fish feeding periodicity. Comparisons were based on ten 24-h samplings of six different yellow perch (Perca flavescens) populations. Daily ration estimates from the two models did not differ significantly. This consistency occurred in spite of the fact that in some cases the observed feeding periodicity violated the assumptions of the Eggers model. A simulation model demonstrated that 95% confidence intervals were smallest for the Eggers estimates and that the Eggers model was more robust than the Elliott and Persson model to changes in both sampling frequency and number offish sacrificed at each sampling event. The latter proved particularly sensitive to changes in sampling frequency. We concluded that the two models provide estimates of daily ration comparable in magnitude and accuracy and consequently that the restriction of the Eggers model to fish with rigid feeding periodicity is not justified. Furthermore, the Eggers model, because of its robustness, reduces the sampling requirements to determine daily ration, and hence, permits its estimation on a more frequent basis.


2019 ◽  
Vol 17 (1) ◽  
pp. e0601
Author(s):  
Alicia Román-Trufero ◽  
Antonio Martínez ◽  
Luis M. M. Ferreira ◽  
Valentín García-Prieto ◽  
Rocío Rosa-García ◽  
...  

Steer meat production in northern Spain is deficient to attend market demand. This research aimed to compare the foraging behaviour and production of yearling steers from two local breeds differing in body weight (BW), Asturian Valley (AV, 372 kg) and Asturian Mountain (AM, 307 kg), grazing in summer pastures consisting of 70% grassland and 30% heathland. Bodyweight gains from a total of 42 steers were recorded during four grazing seasons (from June to October). In two years, in July and September, plant community selection and diet composition were estimated by direct observation and using faecal markers, respectively. Grazing time increased from July to September (488 vs. 557 min/day; p<0.001) as sward height in the grassland decreased. Although AV steers grazed proportionally for longer on herbaceous pastures than AM steers (81.3 vs. 73.3%; p<0.05), no differences between breeds were found in diet composition. AM steers showed greater mean daily BW gains than AV steers (252 vs. 133 g/day; p<0.01). From June to August, steers from both breeds gained BW (487 vs. 360 g/day for AM and AV, respectively; p<0.01), but thereafter BW gains decreased (120 vs. –12 g/day for AM and AV, respectively; p<0.05), because of reduced availability of grassland herbage. Yearling steers from AM breed seem to be better suited to mountain conditions than those from AV breed, probably because of their smaller body size and lower total nutrient requirements for maintenance.


1987 ◽  
Vol 44 (10) ◽  
pp. 1786-1791 ◽  
Author(s):  
Michael T. Arts ◽  
D. O. Evans

A precision micrometer device is described which standardizes measurement of mouth gape of larval fish and provides a greater degree of accuracy and speed than the conventional manual method. We compared gape measurements of larval lake whitefish (Coregonus clupeaformis) and lake herring (Coregonus artedii) using the gape micrometer versus the manual method. The micrometer measurements revealed a greater increase in gape with body length and resulted in a greater proportion of the variance in gape being explained, indicating that the gape micrometer is more sensitive and accurate than the manual method. Coefficient of variation of gape measurements on 238 larval yellow perch (Perca flavescens) decreased with body size from 0.5–4.0% at 0.8–1.2 cm standard length to 0.2–0.5% at 3.0 cm. The device has the added advantage that it could be adapted to connect to a microcomputer for direct data capture.


1991 ◽  
Vol 69 (4) ◽  
pp. 964-972 ◽  
Author(s):  
Wolfgang A. Jansen

Five fish species were sampled at regular intervals in Narrow Lake, central Alberta, and examined for the prevalence and intensity of infestation by glochidia larvae of Anodonta grandis simpsoniana. Yellow perch (Perca flavescens) collected between January and May were infested with glochidia, whereas perch captured between June and October were free of larvae. The prevalence of infestation increased gradually from 86 to 95% between January and May, and the intensity of infestation increased from 5.7 to 49.4 glochidia per fish over the same period. Glochidia were found on most external body surfaces, including the gills. Glochidia attached preferentially to some anatomical areas, especially pectoral and pelvic fins. Furthermore, the relative importance of certain attachment sites differed significantly among sampling dates. Neither sex, size (length or weight), or age of perch significantly affected the intensity of infestation per fish. However, small (4.4–6.0 cm), 1- and 2-year-old fish carried more than 12 times the number of glochidia per gram of body weight than large (12.1–15.7 cm), 4- to 7-year-old fish. Both perch behavior and distribution and clam reproduction and distribution provide possible explanations for the observed patterns in the prevalence and intensity of infestation and in the distribution of the glochidia on the host.


1988 ◽  
Vol 45 (11) ◽  
pp. 1942-1948 ◽  
Author(s):  
Jeffrey A. Malison ◽  
Terrence B. Kayes ◽  
Bernard C. Wentworth ◽  
Clyde H. Amundson

In yellow perch (Perca flavescens) (initially 13–16 g total weight) fed to satiation (3.0–3.5% of body weight per day), estradiol-17β (E2) at 15 μg/g diet stimulated weight gain and food consumption of both sexes but did not influence food conversion efficiency (FCE), as measured by weight gain of fish per weight of food consumed. Females fed to satiation gained more weight, consumed more food, and had higher FCE than males. In perch fed a restricted ration (1.2% of body weight per day), the differences between the sexes in weight gain were reduced and due entirely to differences in FCE, and weight gain was not improved by E2. Spatial segregation or integration of the sexes had no influence on sex-related growth patterns in perch fed either the satiation or restricted ration. Carcass composition of perch treated for 84 d with E2 at 2, 20, or 50 μg/g diet did not differ from that of controls. These data indicate that (1) estrogens promote growth in yellow perch by stimulating food consumption, (2) female perch outgrow males because of both greater food consumption and higher FCE, and (3) growth differences between the sexes are not a consequence of intersexual competition for food.


1976 ◽  
Vol 33 (2) ◽  
pp. 248-267 ◽  
Author(s):  
R. J. Norstrom ◽  
A. E. McKinnon ◽  
A. S. W. deFreitas

A pollutant accumulation model is developed which successfully predicts concentrations of PCBs and methylmercury in tissues of yellow perch (Perca flavescens) from the Ottawa River, Canada. The model is based on pollutant biokinetics coupled to fish energetics. The expression for metabolic rate includes a growth dependent term for estimating the contribution to metabolism of seasonal and annual growth in each age-class. Uptake of pollutant from food is based on caloric requirements for respiration and growth coupled to concentration of pollutant in food and its assimilation efficiency from the diet. Uptake of pollutant from water is based on flow of water past the gills for respiration coupled with concentration of pollutant in water and the efficiency of its assimilation by gills. Pollutant clearance is related to body weight raised to the power of −.58, but is independent of metabolic rate. Under steady state conditions of chronic exposure, the predicted ratio of uptake to clearance is roughly constant at all weights, and the slope of a curve of log pollutant concentration in tissues vs. log body weight can be used to establish the exponent of body weight for clearance.


1972 ◽  
Vol 50 (5) ◽  
pp. 577-584 ◽  
Author(s):  
Norman R. Sinclair

The metacercarial cyst of Apophallus brevis, the "sand-grain grub," is composed of fish bone within peripheral blood vessels of yellow perch (Perca flavescens) forming a tire-like structure; two escape canals are maintained opposite each other. In thin section, lines indicating interruption of growth apparently delimit annual incrementation as in scales and other bony structures of fish. Cysts are oriented with their long axes paralleling the long axis of a host's body with escape canals contiguous to walls of enclosing blood vessels. Cysts of A. brevis in situ at times appear partially or entirely pigmented but are actually transparent; pigmentation, when present, is a phenomenon of a cyst's position within certain types of blood vessels and is not an integral part of a cyst's construction. The organism as a metacercaria is almost exclusively a parasite of yellow perch (known deviations are noted) and is apparently confined to North America, having a known broad range from Saskatchewan to Cape Cod. Massachusetts. Distribution is extremely diffuse and appears dependent on patchy distribution of the organism's molluscan host, Amnicola limosa. Geographical variation in cyst site selection and clustering indicates some sort of intraspecies inhibition on the part of metacercariae of A. brevis.


1972 ◽  
Vol 29 (12) ◽  
pp. 1761-1764 ◽  
Author(s):  
Brian Wong ◽  
F. J. Ward

Prior to mid-July, Daphnia pulicaria in yellow perch (Perca flavescens) fry stomachs were smaller than those in plankton collections but after this date mean lengths of D. pulicaria in stomachs and collections were similar indicating an initial selection for small D. pulicaria by the fish. The relation between D. pulicaria body depth and perch mouth gape width indicated that perch fry less than 18 mm long, a length attained in mid-July, could not readily ingest D. pulicaria with body depths greater than 0.7 mm (1.3 mm long). The heterogenic relation between growth in mouth and body size enabled perch fry in West Blue Lake to quickly utilize, as an energy source, the abundant D. pulicaria population.


2000 ◽  
Vol 57 (2) ◽  
pp. 441-450 ◽  
Author(s):  
Graham D Sherwood ◽  
Joseph B Rasmussen ◽  
David J Rowan ◽  
Julie Brodeur ◽  
Alice Hontela

While the flow of energy is understood to determine the growth of organisms and the productivity of ecosystems, little is known about the sublethal effect of pollutants on the energetic efficiency of wild populations. We used field estimates of fish growth coupled to in situ estimates of food consumption rates obtained from the mass balance of a globally dispersed, trophically transferred radiotracer (137Cs) to demonstrate the bioenergetic impairment of yellow perch (Perca flavescens) from lakes polluted by heavy metals (Cd, Cu, and Zn). Annual growth increment relative to the total energy budget (conversion efficiency) was about three times lower in cortisol-impaired yellow perch from metal-polluted lakes relative to yellow perch from reference lakes (4.2% compared with 10.8%), suggesting that fish exposed to pollutants experienced greater total energetic costs. In addition, metal-polluted lakes were dominated by adult yellow perch populations and simplified prey bases, suggesting that effects are occurring at multiple levels of biological organization. Our in situ bioenergetic approach to toxicity assessment provides a measurable and ecologically relevant endpoint for assessing the sublethal effects of pollutants on fish communities.


1986 ◽  
Vol 43 (1) ◽  
pp. 26-35 ◽  
Author(s):  
Jeffrey A. Malison ◽  
Terrence B. Kayes ◽  
Cody D. Best ◽  
Clyde H. Amundson ◽  
Bernard C. Wentworth

Morphological and histologial studies demonstrated that estrogens and androgens affect sexual differentiation and can be used to control the phenotypic sex of yellow perch (Perca flavescens). Normal perch larvae of 5–10 mm total length (TL) had paired gonads with no sex-distinguishing features. In normal 16 mm TL perch, the gonads of females had fused into a single sac-shaped organ, while in males the gonads remained paired. Oogenesis had begun in most females of 35 mm TL. Spermatogenesis in males and vitellogenesis in females were first observed at 85 mm TL. Treatment (for 84 d) of perch (initially 20–35 mm TL) with estradiol-17β at 15–120 μg/g diet induced complete germ cell sex inversion in most males. Similar treatment with 17α-methyltestosterone at 1.5 to 60 μg/g diet induced spermatogenesis and the formation of ovotestes in females. Sperm collected from such ovotestes fertilized normal ova, and the resultant offspring were all female. Our findings indicate that in yellow perch: (1) differentiation of the somatic elements of the gonads precedes gametogenesis, (2) gametogenesis begins earlier in females than in males, (3) the attainment of a specific minimum body size (80–100 mm TL) is important to the initial onset of vitellogenesis and spermatogenesis, (4) both estrogens and androgens are probably involved in mediating sexual differentiation of germinal tissues and (5) females are the homogametic sex.


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