Coastal populations of brook trout, Salvelinus fontinalis, in Lac Guillaume-Delisle (Richmond Gulf) Québec

1980 ◽  
Vol 58 (10) ◽  
pp. 1828-1835 ◽  
Author(s):  
J. D. Dutil ◽  
G. Power
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Age Groups ◽  
Fork Length ◽  
Anadromous Fish ◽  
Coastal Streams ◽  
River Mouths ◽  
Fish Dispersal

Brook trout grow slowly in coastal streams and resident fish average only 15.6 cm during their fourth summer. Anadromous fish move into brackish water at approximately 20 cm fork length. In the gulf, the modal age is 4+ and age groups 3+ to 6+ account for 80–90% of the catch. Fish rapidly attain lengths of 35–40 cm, instantaneous growth in weight decreases from 1.27 for 2- to 3-year-old fish to 0.35 for 5- to 6-year-old fish. Dispersal from river mouths may be restricted to a distance of only 5–6 km. Late in July and throughout August, maturing fish of both sexes enter fresh water where ripening occurs. Movements at sea and duration of residence are controlled by salinity and temperature as influenced by maturation.

A nonlethal approach using strontium in scales to distinguish periods of marine and freshwater residency of anadromous species

2005 ◽  
Vol 62 (11) ◽  
pp. 2443-2449 ◽  
Author(s):  
David A Courtemanche ◽  
Frederick G Whoriskey, Jr. ◽  
Valerie Bujold ◽  
R Allen Curry
Keyword(s):  
Cross Sections ◽  
Electron Microprobe ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Cost Effective ◽  
Anadromous Fish ◽  
Migration Patterns ◽  
X Ray ◽  
History Of ◽  
Scale Surface

Spatiotemporal migration patterns of brook trout (Salvelinus fontinalis) and various other anadromous fish are poorly understood in many rivers of North America. A new, nonlethal approach to investigate these movements using analysis of scale microchemistry was developed that is relatively simple, cost effective, and potentially more accurate than other monitoring techniques. As fish grow, their scales incorporate in the calcified matrix different concentrations of trace elements present in ambient waters. Seawater Sr concentrations are 10–100 times higher compared with fresh water; thus, a higher Sr/Ca ratio in circulii corresponding to periods of life in seawater would be predicted. We used a wavelength-dispersive X-ray electron microprobe to assess Sr/Ca ratios along sagittal cross sections of scales, spanning the life history of a fish. We demonstrate that existing wavelength-dispersive X-ray electron microprobe studies using Sr analysis may suffer inaccuracies related to scale surface topography, and using the alternative embedding and cutting technique increases significantly the precision of Sr/Ca readings.

Comparative Behavior and Habitat Utilization of Brook Trout (Salvelinus fontinalis) and Cutthroat Trout (Salmo clarki) in Small Streams in Northern Idaho

1972 ◽  
Vol 29 (3) ◽  
pp. 265-273 ◽  
Author(s):  
J. S. Griffith Jr.
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Age Groups ◽  
Cutthroat Trout ◽  
Habitat Characteristics ◽  
Stream Channels ◽  
Sympatric Populations ◽  
Small Streams ◽  
Northern Idaho ◽  
Salmo Clarki

Individual brook (Salvelinus fontinalis) and cutthroat (Salmo clarki) trout communicated with similar behavioral signals, both in laboratory stream-channels and in northern Idaho streams. Underyearling brook trout were less active socially than equal-sized cutthroat trout in laboratory observations. In study streams, brook trout maintained a 20-mm size advantage over cutthroat of the same age-groups throughout their lives, as they emerged from the gravel before cutthroat. Because of this size advantage, underyearling brook trout of sizes found in study streams in September consistently dominated in experiments the underyearling cutthroat with which they normally lived. But in study streams underyearlings of the two species utilized different microhabitats, particularly with respect to water depth, and so minimized chances for interaction.Yearling and older brook trout initiated 40% fewer aggressive encounters under laboratory conditions than did equal-sized cutthroat trout, and did not displace the cutthroat. In study streams with sympatric populations, cutthroat trout of these age-groups occupied territories with focal points of higher water velocities (averaging 10.2–10.3 cm/sec) than those occupied by brook trout (averaging 7.6–9.6 cm/sec). Considerable interspecific overlap in other habitat characteristics occurred for trout of age-groups I and II. The oldest members of the two species segregated more distinctly, as the brook trout lived closer to overhead cover.

Life History of Sea-Running Brook Trout (Salvelinus fontinalis) of Moser River, N.S.

1940 ◽  
Vol 5a (2) ◽  
pp. 176-186 ◽  
Author(s):  
H. C. White
Keyword(s):  
Life History ◽  
Fresh Water ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Large Fish ◽  
History Of

Smolts, kelts and non-mature large fish descend in May and early June to the sea, to remain feeding in the estuary or near the shore. They began (1939) to ascend the river in late June, and 93% of the "run" was in July.Fish marked when descending one branch of the river ascended both that branch and the river above but the proportion of marked fish was greater in the branch.These trout agree with the local salmon in having smolts that become silvery before migration and that are two or three years old. Trout smolts and kelts remain in the sea only about two months before returning to fresh water.

Winter Habitat Utilization by Stream Resident Brook Trout (Salvelinus fontinalis) and Brown Trout (Salmo trutta)

1986 ◽  
Vol 43 (10) ◽  
pp. 1970-1981 ◽  
Author(s):  
Richard A. Cunjak ◽  
Geoffrey Power
Keyword(s):  
Brown Trout ◽  
Brook Trout ◽  
Salmo Trutta ◽  
Salvelinus Fontinalis ◽  
Focal Point ◽  
Age Groups ◽  
Habitat Utilization ◽  
Point Sources ◽  
Energetic Cost ◽  
Brown Trout Salmo Trutta

Habitat utilization by brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) is described from three winters of underwater observations in a southern Ontario river. Older trout (>age 1) generally occupied positions in deeper and faster water than age 0+ trout. In winter, at sites of sympatry, brown trout occupied greater focal point water depths than brook trout; both species had similar focal point water velocities. At all sites, and for both age groups and species, there was a strong preference for positions beneath cover. Relative to summer, trout positions in winter were characterized by slower water velocities and greater overhead cover, In winter, most trout were in aggregations, usually in pools beneath cover and close to point sources of groundwater discharge. Gregarious behaviour appeared to increase as water temperatures decreased; no such relationship was evident in the summer. Specific strategies for overwintering varied between sites and age groups but generally conformed to the theory of energetic cost minimization for position choice. These variable patterns appear to be adaptive.

Concentrations of nucleic acids and protein as indices of nutritional status for recently emerged brook trout (Salvelinus fontinalis)

1995 ◽  
Vol 52 (4) ◽  
pp. 848-854 ◽  
Author(s):  
Robert L. McLaughlin ◽  
Moira M. Ferguson ◽  
David L. G. Noakes
Keyword(s):  
Nutritional Status ◽  
Nucleic Acids ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Life Stage ◽  
Fork Length ◽  
Tissue Concentrations ◽  
Dna And Rna ◽  
Wild Trout ◽  
Rna And Dna

We examined whether concentrations of nucleic acids and protein sampled from muscle tissue were useful indicators of nutritional status for recently emerged brook trout (Salvelinus fontinalis). Trout collected from the field were maintained in the laboratory under two food treatments: fed versus food deprived. Concentrations of RNA and DNA, and RNA/DNA ratio did not differ significantly between fed and food-deprived trout, but fed trout had higher concentrations of protein and were 20% heavier at a given fork length than food-deprived trout. Wild trout fed in the laboratory had lower concentrations of RNA, DNA, and protein, and lower RNA/DNA ratios than did trout in the field, but were significantly heavier for their fork length. Tissue concentrations of protein may provide an index of nutritional status for recently emerged brook trout while concentrations of nucleic acids apparently do not. It is important to ensure that concentrations of nucleic acids and protein reflect nutritional status adequately for the species and life stage of interest before using these indices to assess the condition of fish in the field.

Goezia bangladeshi n. sp. (Nematoda: Anisakidae) from an anadromous fish Tenualosa ilisha (Clupeidae)

2004 ◽  
Vol 78 (2) ◽  
pp. 105-113 ◽  
Author(s):  
M. Akther ◽  
A. Alam ◽  
J. D'Silva ◽  
A.I. Bhuiyan ◽  
G.A. Bristow ◽  
...  
Keyword(s):  
Fresh Water ◽  
Definitive Host ◽  
Brackish Water ◽  
Intestinal Caecum ◽  
Infected Fish ◽  
Fish Host ◽  
Length Ratio ◽  
Valid Species ◽  
Anadromous Fish ◽  
Tenualosa Ilisha

AbstractA total of 1432 hilsa shad, Tenualosa ilisha (=Hilsa ilisha) from 11 fresh water, brackish water and marine localities in Bangladesh yielded 13 adult Goezia bangladeshi n. sp., all specimens being found in the intestine of a single fish host caught in the lower Ganges. A total of 2372 Goezia juveniles were recovered from 490 infected fish (prevalence 34.2%). This is the first Goezia species recorded from Bangladesh, and it differs from other valid species by the number of caudal papillae (pre 7–9, para 3, post 6); encircled by tiny spines, the position of double papillae, the arrangement of body spines, and the length ratio of the intestinal caecum and the ventricular appendix (1: 3.33–4.72). Juveniles were free in the gut, embedded in the gut wall and encapsulated in mesenteries. Tenualosa ilisha serves as the definitive host, but the predominance of juveniles may indicate that piscivorous hosts may also serve as such. A list of the nominal Goezia species with important characters is provided.

A dense cell in the epithelium of the gill lamellae of the fresh-water brook trout, salvelinus fontinalis

1978 ◽  
Vol 36 (2) ◽  
pp. 450-451
Author(s):  
C. M. Morrison
Keyword(s):  
Fresh Water ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Salt Water ◽  
Uranyl Acetate ◽  
Chloride Cells ◽  
Salmo Gairdneri ◽  
Basal Nucleus ◽  
Thin Sections ◽  
Gill Lamellae

Introduction Unspecialized, dark, chloride and mucous cells have been described in the epithelium of the gill lamellae of Salmo gairdneri and the chloride cell of fresh-water Salvelinus fontinalis has been described. In the course of other studies we found another cell type in the epithelium of fresh-water Salvelinus fontinalis, which is described in the following account.Methods Six fresh-water brook trout, and two adapted to salt-water were killed by a blow on the head, and gill filaments were removed, fixed in Karnovsky's fixative then osmium tetroxide, dehydrated in acetone and embedded in epoxy resin. Thin sections for electron microscopy were stained with 25% uranyl acetate in methanol and lead citrate.Observations The epithelial cells described in Salmo gairdneri were also found in Salvelinus fontinalis, but another type was seen in fresh-water Salvelinus fontinalis. These cells were often as large as chloride cells and had a similar shape, but the cytoplasm and basal nucleus were usually darker, round vesicles were present in the apical cytoplasm, and large membrane-bound bodies were often present in the basal cytoplasm (Fig. 1).

The Effect of Polychlorinated Biphenyl on Steroidogenesis and Reproduction in the Brook Trout (Salvelinus fontinalis)

1975 ◽  
Vol 53 (6) ◽  
pp. 666-670 ◽  
Author(s):  
H. C. Freeman ◽  
D. R. Idler
Keyword(s):  
Fresh Water ◽  
Brook Trout ◽  
Polychlorinated Biphenyl ◽  
Salvelinus Fontinalis ◽  
Testicular Tissue ◽  
Control Group ◽  
Blood Levels ◽  
Treated Fish ◽  
Reproduction Process

Livers from brook trout (Salvelinus fontinalis) held in water containing 3.8 p.p.m. (mg/1) Corexit and in water containing 3.8 p.p.m. Corexit + 0.2 p.p.m. polychlorinated biphenyl (PCB) were firmer in texture than livers taken from control trout held in fresh water. The testes from the PCB-treated trout were darker in color, smaller in size, contained less spermatic fluid, and appeared to be regressed when compared with testes from the control fish.Only 72% of the eggs from PCB-treated trout hatched compared to 92% for control eggs when eggs were incubated in fresh water. Fertilized eggs incubated in water containing 0.2 p.p.m. PCB + 3.8 p.p.m. Corexit resulted in less than 1% of the eggs from the untreated fish and none of the eggs from PCB-treated fish being hatched. The young fish from the control group lived only a few days in the water containing PCB.PCB greatly stimulated the in vitro 11β-hydroxylation of testosterone by trout testicular tissue. There was no significant change in 11-ketotestosterone blood levels in maturing brook trout after treatment with 3.8 p.p.m. Corexit or 3.8 p.p.m. Corexit + 0.2 p.p.m. PCB for 21 days during the final stages of maturation. It is thought that sublethal levels of PCB can interfere with the reproduction process in this species.

Marine feeding patterns of anadromous brook trout (Salvelinus fontinalis) inhabiting an estuarine river fjord

2006 ◽  
Vol 63 (9) ◽  
pp. 2011-2027 ◽  
Author(s):  
Geneviève R Morinville ◽  
Joseph B Rasmussen
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
First Year ◽  
Feeding Patterns ◽  
Sea Trout ◽  
Marguerite Bay ◽  
Saguenay River ◽  
River Mouths ◽  
Isotope Analyses ◽  
Prey Items

This study describes the ontogenetic and seasonal feeding patterns of anadromous brook trout (Salvelinus fontinalis, also known as sea trout) inhabiting the estuarine Saguenay River (Quebec, Canada) using both stomach content and stable isotope analyses. Sea trout of the Ste. Marguerite River (Quebec, Canada) entered the saline waters of the Ste. Marguerite Bay in early May before venturing into the Saguenay River fjord for the remainder of the summer period. Upon their arrival, first-year migrants stayed relatively close to river mouths and initially fed on freshwater aquatic invertebrates. However, they quickly shifted their diet to marine prey items such as amphipods and mysids for the rest of their first summer at sea. These prey items were generally larger than freshwater prey; the prey spectrum at sea was both larger and wider than that found in freshwater and, as such, likely contributed to the trout's rapid growth rates at sea. The diet of migrants in subsequent years at sea (second-year migrants) consisted primarily of marine crustaceans and fish, the latter being most important when feeding in the upper Saguenay River. Trout shifted to piscivory at all marine sites at a size of 25 cm, regardless of time spent at sea, although the importance of piscivory varied with season and site.

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