Fecundity and Egg Size of a Brood Stock of Salvelinus fontinalis × S. namaycush Hybrids (Splake)

1974 ◽  
Vol 31 (2) ◽  
pp. 217-220 ◽  
Author(s):  
G. B. Ayles
Keyword(s):  
Egg Size ◽  
Lake Trout ◽  
Salvelinus Fontinalis ◽  
Lake Huron ◽  
Female Size ◽  
Brood Stock ◽  
Trout Population ◽  
Egg Diameter

Estimates of average egg diameter and average number of eggs per female from a brood stock of Salvelinus fontinalis × S. namaycush (splake) hybrids were 0.468 cm and 1169 eggs, respectively. Variation in egg size between females was attributable to variation in both size and age of the fish, whereas differences in fecundity were attributed only to differences in female size. At a given size a splake had more and larger eggs than have been reported for lake trout. The significance of the findings is discussed in relation to the reestablishment of a viable trout population in Lake Huron.

The White Sucker Population of South Bay, Lake Huron, and Effects of the Sea Lamprey on It

1967 ◽  
Vol 24 (10) ◽  
pp. 2117-2136 ◽  
Author(s):  
Daniel W. Coble
Keyword(s):  
Lake Trout ◽  
Fork Length ◽  
Size Composition ◽  
Sea Lamprey ◽  
Lake Huron ◽  
Minimal Distance ◽  
Alosa Pseudoharengus ◽  
White Sucker ◽  
Trout Population ◽  
Relationship Of

Information on ecology and dynamics of white suckers, Catostomus commersoni (Lacépède), in South Bay, Lake Huron, was obtained from experimental fishing over more than a decade and from a tagging program in 1955 and 1956. (A total of 1667 suckers were tagged and 8% of them were subsequently recovered.) The fish moved about extensively in the bay, minimal distance travelled averaging 3.8 km during a summer. Nevertheless, it was necessary to divide the bay into discrete fishing areas for calculating population and mortality estimates. The length–weight relationship of adult suckers in June was W = 5.883 × 10−4 L2.92262; where W is weight in pounds and L is fork length in inches. Growth averaged only about 7.6 mm/year, and an annulus was not formed on the scales every year. In 1956 the population may have amounted to about 160,000 adult white suckers, or 23 fish per hectare or 17.5 kg/hectare, for the part of the bay less than 36 m deep. The exploitation rate appeared to be less than 2%. The annual survival rate of suckers larger than approximately 38 cm appeared to be about 70–75% decreasing with size of fish. Although it is not known if the size of the population has changed, the size composition changed between 1953 and 1964 through the loss of larger fish. Marked changes in the fauna of South Bay subsequent to the late 1940's include the invasion of the sea lamprey, Petromyzon marinus Linnaeus, and the alewife, Alosa pseudoharengus (Wilson), the disappearance of the lake trout, Salvelinus namaycush (Walbaum), and the decline of the population of the cisco, Coregonus (= Leucichthys) artedii LeSueur. The loss of the larger fish in the white sucker population was probably caused by the sea lamprey, for it occurred after the destruction of the lake trout population and corresponded with increased incidence of lamprey scarring of suckers.

Population Dynamics of F1 Splake (Salvelinus fontinalis × S. namaycush) in Lake Huron

1970 ◽  
Vol 27 (6) ◽  
pp. 1017-1032 ◽  
Author(s):  
A. H. Berst ◽  
G. R. Spangler
Keyword(s):  
Population Dynamics ◽  
Sexual Maturity ◽  
Lake Trout ◽  
Salvelinus Fontinalis ◽  
Early Summer ◽  
Lake Huron ◽  
Commercial Fisheries ◽  
South Shore ◽  
Old Females ◽  
Commercial Size

Ninety-eight percent of 5391 F1 splake recovered from a 1966 planting of 49,000 yearlings in Burnt Island Bay (45°50′N, 82°57′W) on the south shore of Manitoulin Island were taken within 32 km (20 miles) of the planting site. Remaining recaptures were made at distances up to 322 km (200 miles).Growth rates of the hybrids in Lake Huron exceeded those reported for native and planted lake trout. A commercial size of 0.9 kg (2 lb) round weight was attained by the fall of their 2nd year in the lake. The splake grew rapidly through the winter months. Yearlings fed mainly on invertebrates and 2- to 4-year-olds fed almost entirely on fish.Eight percent of 3054 hybrids examined had one or more lamprey marks. Fish less than 30 cm (12 inches) bore no evidence of lamprey attack; larger hybrids showed frequencies of lamprey marks increasing from 5.4% for 30- to 40-cm fish to 11.6% for those larger than 40 cm. The incidence of fresh lamprey marks was minimal in spring and early summer and reached a peak in September when more than 20% of the specimens bore fresh marks.Of the 2- and 3-year-old splake recovered, 50 and 40%, respectively, were males. The onset of sexual maturity in both sexes occurred at age II. By age III, 86% of the males and 58% of the females were mature. Ripe 3-year-old hybrids of both sexes were captured over former lake trout spawning grounds. Fecundity of 3-year-old females averaged 2512 eggs. Although survival to age IV was low, a substantial number of the hybrids attained sexual maturity.A total of 8.4% of the planting of 49,000 yearling hybrids was reported taken by sport and commercial fisheries during a 3-year period.

Bénéfices à court terme des mouvements anadromes saisonniers pour une population d'omble de fontaine (Salvelinus fontinalis) du Nouveau Québec

1991 ◽  
Vol 48 (11) ◽  
pp. 2212-2222 ◽  
Author(s):  
Jean-François Doyon ◽  
Christiane Hudon ◽  
Roderick Morin ◽  
F. G. Whoriskey Jr.
Keyword(s):  
Water Level ◽  
Egg Size ◽  
Salvelinus Fontinalis ◽  
Condition Factor ◽  
Size At Maturity ◽  
Brook Charr ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Single Population ◽  
Energetic Reserves

This study characterizes the seasonal anadromous movements of a brook charr population and compares its biological and energetic characteristics with charr spending summer in freshwaters. Downstream movements monitored at a counting fence over 3 yr were most intense in spring but occurred until fall and were positively correlated with rapid increases of water level. The timing of movements varied from year to year. Smaller charr were most subject to being swept downstream compared with freshwater residents, and most trout were concentrated near the mouth of the river. These patterns suggest that the downstream movements of charr in this system are passive. Upstream migrants had a higher condition factor and a lower tissue water content than freshwater residents, indicating that downstream movements result in a faster accumulation of energetic reserves during summer. However, the fortuitous character of anadromous migrations as well as the absence of differences in the biological characteristics (growth, size at maturity, fecundity, egg size) suggests that anadromous and resident fish belong to a single population whose yearly migrant component could be randomly determined.

Experimental Plantings of Brook Trout (Salvelinus fontinalis) from Furunculosis-Infected Stock

1968 ◽  
Vol 25 (12) ◽  
pp. 2643-2649 ◽  
Author(s):  
L. A. McDermott ◽  
A. H. Berst
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Infected Fish ◽  
Aeromonas Salmonicida ◽  
Control Fish ◽  
Southern Ontario ◽  
Trout Population ◽  
Hatchery Stock ◽  
Associated Species ◽  
Made In

Preliminary sampling revealed the presence of furunculosis disease in the resident brook trout population of the southern Ontario trout stream used in this study.Two plantings of marked yearling brook trout were made in the study area in 1966; one in the spring, and the other in the fall. The spring planting consisted of 1000 brook trout with a predetermined incidence of furunculosis infection and an equal number of trout with no evidence of infection. The fall planting consisted of 2000 brook trout with a known incidence of furunculosis infection.The stream was electrofished periodically during the 2-year period after the first planting. A total of 445 brook trout (140 of the planted hatchery stock, and 305 resident trout) and 127 fish of associated species were captured and examined for the presence of Aeromonas salmonicida, causative agent of furunculosis.Recovery rates of the "infected" and "noninfected" stocks of brook trout were similar, and there was no evidence of transmission of A. salmonicida from the infected fish to the control fish, nor the resident population of brook trout and other species of fish captured.

Cross-basin comparison of mercury bioaccumulation in Lake Huron lake trout emphasizes ecological characteristics

2014 ◽  
Vol 34 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Rachel A. Abma ◽  
Gordon Paterson ◽  
Anne McLeod ◽  
G. Doug Haffner
Keyword(s):  
Lake Trout ◽  
Lake Huron ◽  
Ecological Characteristics ◽  
Mercury Bioaccumulation

Geographic distribution, species displacement, and niche overlap for lake trout and bull trout in mountain lakes

1993 ◽  
Vol 71 (2) ◽  
pp. 238-247 ◽  
Author(s):  
David B. Donald ◽  
David J. Alger
Keyword(s):  
Trophic Structure ◽  
Lake Trout ◽  
Niche Overlap ◽  
Mountain Lakes ◽  
Bull Trout ◽  
Salvelinus Confluentus ◽  
East Central ◽  
Allopatric Populations ◽  
Trout Population ◽  
The One

Indigenous lacustrine populations of bull trout (Salvelinus confluentus) and lake trout (S. namaycush) are spatially separated within the southern part of the zone of distributional overlap (northern Montana, southwestern Alberta, and east-central British Columbia). In this area, lake trout occurred primarily in mountain lakes of 1032–1500 m elevation, while bull trout were found primarily in lakes between 1500 and 2200 m. Introductions of lake trout in the twentieth century and data obtained from beyond the study area indicated that both fishes can establish significant allopatric populations (more than 5% of the catch) in large, deep lakes (>8 ha in area and >8 m deep) over a wide elevation range. We tested the hypothesis that lake trout displace or exclude bull trout from lakes by determining the outcome of introductions of lake trout into two lakes that supported indigenous bull trout. Lake trout were introduced into Bow Lake in 1964, and by 1992 the bull trout population was decimated there and in another lake (Hector) situated 15 km downstream. Thus, lake trout can displace bull trout and may prevent bull trout from becoming established in certain low-elevation lakes. Population age-structure analyses also suggest that lake trout adversely affected bull trout. Bull trout populations in sympatry with lake trout, including the one extirpated from Hector Lake, had few old fish (18% were more than 5 years old; N = 40 fish from three lakes) compared with allopatric populations (49% were more than 5 years old; N = 235 fish from seven lakes). Niche overlap and the potential for competition between the two char species were substantial. In lakes with trophic structure ranging from simple to complex, bull trout and lake trout fed on similar foods and had similar ecological efficiencies (growth rates). Predation by lake trout on bull trout was not documented during the study.

The Thermal Regime of South Bay, Manitoulin Island

1967 ◽  
Vol 24 (1) ◽  
pp. 101-125 ◽  
Author(s):  
A. M. McCombie
Keyword(s):  
Thermal Regime ◽  
Thermal Stratification ◽  
Yellow Perch ◽  
Lake Trout ◽  
Smallmouth Bass ◽  
Lake Huron ◽  
Vertical Temperature ◽  
Class Strength ◽  
Influence Of Temperature On ◽  
History Of

The thermal regime of South Bay is described from records collected from 1953 to 1962 with thermometers, thermographs, and bathythermographs, the last being cast at 11 stations along the bay and one in Lake Huron. Warming begins in April and thermal stratification is established in June. Shallow areas warm more rapidly than deep in the spring and cool more quickly in autumn. The boundary between the epilimnion and the thermocline becomes sharper as summer advances but the transition from thermocline to hypolimnion remains gradual. The average seasonal trend of surface temperatures is a sine function with a maximum of 66 F in mid August and a minimum of 34 F in late March, though values outside this range occur frequently. At 180 ft the maximum of 47 F is attained in November. At the lake and outermost bay stations there is a temperature slump in June and July which may be due to an upwelling in the lake. Evidence of an exchange of water between the lake and bay is seen in vertical temperature sections and water movements Variations in epilimnial temperatures are correlated with those of the air temperature, but variations in epilimnial and hypolimnial temperatures appear to be unrelated. Finally, literature describing the influence of temperature on the year class strength of smallmouth bass, the distribution of lake trout, the growth of yellow perch, and the life history of Pontoporeia in South Bay is reviewed.

Studies on fecundity and spawning of blue crab (Callinectes Amnicola) in Cross River Estuary

2021 ◽  
Vol 36 (1) ◽  
pp. 75-82
Author(s):  
J. Otoyo ◽  
S.M. Ameh ◽  
O.K. Achema
Keyword(s):  
Blue Crab ◽  
Egg Size ◽  
Gonadosomatic Index ◽  
Carapace Width ◽  
River Estuary ◽  
Hepatosomatic Index ◽  
Cross River ◽  
The Cross ◽  
Cross River Estuary ◽  
Egg Diameter

Studies on identification of species, fecundity and development stages of blue crab, (Callinectes amnicola) were investigated at the Cross River Estuary between the months of December, 2018 and May, 2019. The parameters used for the study were gonadosomatic and hepatosomatic indices, egg diameter and counts. All measurements followed standard procedures. Gonadosomatic index was at its peak in December (88.9) and April (83.3). This coincided with the peak in egg size suggesting that spawning occurred twice within the period.The low values of hepatosomatic index around December (1.20) and April (0.45) added to confirm the spawning in these months. The species spawns at a mean egg size of 17.55mm. The dimension of crabs examined were in the following range: carapace length 40.0 to 70.0mm, carapace width, 5.0 to 60mm and body weight 40.0 to 140.0g. The relationship between fecundity and weight of crab was  significant (r = 0.295: p<0.05), indicating positive correlation. Absolute fecundity of the species ranged between 1,375 and 225,132 eggs. The smallest crab with egg had a carapace width of 39.5mm and weight of 46.9g. Spawning at this size seems to be a strategy adopted by the species to cope with exploitation pressure. The result of this study revealed that C. amnicola had a high reproductive potentials. Hence, adequate regulation is required to enhance sustainability of the species in the Cross River Estuary.

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