Distribution of Insular Fishes of Sable Island, Nova Scotia

1969 ◽  
Vol 26 (5) ◽  
pp. 1390-1392 ◽  
Author(s):  
E. T. Garside

Collections of fishes from the several bodies of fresh and brackish waters on Sable Island, Nova Scotia (60°06′W, 43°56′N), were composed variously of four euryhaline species: Fundulus heteroclitus (Cyprinodontidae), Gasterosteus wheatlandi, Apeltes quadracus, and Pungitius pungitius (Gasterosteidae). Sight records are reported for Anguilla rostrata (Anguillidae).

1974 ◽  
Vol 31 (6) ◽  
pp. 1135-1139 ◽  
Author(s):  
George Hanek ◽  
Kalman Molnar

In 224 fish of nine species from Matamek River system 38 genera of parasites were recovered (12 Protozoa, 3 Monogenea, 6 Digenea, 6 Cestoda, 6 Nematoda, 2 Acanthocephala, 3 Copepoda). Six genera of parasites were noted in Salmo salar, Salvelinus fontinalis harbored 17 genera, S. alpinus 5 genera, Osmerus mordax 4 genera, Anguilla rostrata 9 genera, Catostomus catostomus 8 genera, Apeltes quadracus 1 genus, Gasterosteus aculeatus 12 genera, and Pungitius pungitius 9 genera.


1975 ◽  
Vol 53 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Michael Wiles

Morphological and morphometric comparisons among adult and glochidial unionids from two Nova Scotian locations showed that Anodonta implicata, A. cataracta cataracta, A. c. fragilis, Elliptio complanatus, and Lampsilis radiata radiata were present. Gravidity studies suggested that fully developed glochidia occur from September to May in Anodonta marsupia, for only 5–6 weeks in June and July in E. complanatus, and perhaps at least from spring to early fall in L. r. radiata. Seven of 12 fish species sampled bore glochidia, which were identified in five host species by comparisons of their shapes and dimensions with those of glochidia from adult clams. Results were as follows: A. c. cataracta in Catostomus commersoni in June only, A. implicata or A. c. cataracta in Gasterosteus aculeatus in May and June, Anodonta sp. in Apeltes quadracus and Pungitius pungitius in June, and E. complanatus in Fundulus diaphanus in June and July. Thus, no relationships between gravidity periods of adult clams and infestation periods of their fish hosts by their glochidia were evident for species of Anodonta.


1968 ◽  
Vol 25 (8) ◽  
pp. 1591-1602 ◽  
Author(s):  
S. G. Miles

In an experimental apparatus, elvers of the American eel (Anguilla rostrata) showed a stronger positive rheotaxis to fresh water than to salt water. The attractiveness of the fresh water was due to dissolved and particulate organic matter; these components were bio-degradable, heat stable, and nonvolatile. Four streams near Halifax, Nova Scotia, were tested, and were found to differ greatly in their attraction of elvers. Elvers were collected from each of three of these streams, and were not found to be attracted to their own stream water; elvers from one stream gave a greater rheotactic response than elvers from the other streams. The presence of adult eels in the water rendered it more attractive, whereas the presence of elvers made it less so.


2016 ◽  
Vol 541 ◽  
pp. 765-775 ◽  
Author(s):  
Cyril Rigaud ◽  
Catherine M. Couillard ◽  
Jocelyne Pellerin ◽  
Benoît Légaré ◽  
Jonathan D. Byer ◽  
...  

2000 ◽  
Vol 78 (6) ◽  
pp. 923-930 ◽  
Author(s):  
Robert M Dawley ◽  
Amy M Yeakel ◽  
Keith A Beaulieu ◽  
Kristen L Phiel

Hybrids of the killifishes Fundulus diaphanus and Fundulus heteroclitus, found at two sites on the Atlantic coast of Nova Scotia, are unisexual diploid gynogens. Because there seemed to be many opportunities for the sexual progenitor species to hybridize and form new clones at these sites, we initially had expected that clonal diversity might be high among the hybrids. However, examination of their histocompatibility genomes, via inter-individual scale grafting, provides evidence, albeit not conclusive, that most of the hybrids at the two sites, which are separated by 125 km, comprise a single clone. Grafts made among F. diaphanus were rejected within an average of 16-20 days, establishing that sufficient diversity exists within the histocompatibility genomes of these fish to permit their immune systems to reject foreign melanophores. Grafts made from F. diaphanus to the hybrids were also rejected, within an average of 17-26 days, demonstrating that the hybrids possessed competent immune systems. Grafts made between hybrids were nearly always accepted. Those few that appeared to be rejected were usually accepted when regrafted. Melanophores carried on the graft remained visible for the duration of the study (90-180 days) or, if they slowly disappeared, they did so at a rate comparable with that of autograft scales.


2013 ◽  
Vol 70 (12) ◽  
pp. 1805-1812 ◽  
Author(s):  
Allison Schein ◽  
Simon C. Courtenay ◽  
Karen A. Kidd ◽  
K. Alexander Campbell ◽  
Michael R. van den Heuvel

This study compared food web structure in eutrophied Ulva lactuca-dominated areas within an estuary in the Southern Gulf of St. Lawrence, with Zostera marina beds within the same estuary. The estuarine food web consisted only of primary producers, mesograzers, and secondary grazers, with the absence of piscivorous top predators. It was hypothesized that the altered plant habitat would lead to structural changes in the food web and the dominance of benthic carbon. Stomach contents from mummichog (Fundulus heteroclitus), fourspine stickleback (Apeltes quadracus), and American eel (Anguilla rostrata) showed that only mummichog had significant differences in prey items between the different habitats. Stable isotopes showed that there were no significant differences in the food web structure and individual species’ 13C values. A 13C spike in particulate organic matter during the onset of anoxia in July, presumably due to bacterial blooms, indicated the complete dominance of benthic carbon the pelagic food web during this month. Thus, blooms of heterotrophs during anoxic events may have the greatest influence on nutrient cycling in estuaries undergoing eutrophication.


1987 ◽  
Vol 65 (11) ◽  
pp. 2651-2657 ◽  
Author(s):  
D. M. Blouw ◽  
D. W. Hagen

We investigated temporal variation in polymorphisms for the number of dorsal spines in the fourspine stickleback, Apeltes quadracus, and in the ninespine stickleback, Pungitius pungitius, to complement studies based on geographic variation. The changes in spine number that occurred over a 10-year period at Daigle Inlet, New Brunswick, are small relative to geographic variation among sites in the Maritime Provinces. However, some statistically significant changes occur in both species: they take place at or near reproduction; there is no evidence that they are related to selection by predators or any other environmental factor that we measured; and they tend to be followed by reversals that damp the net change. Contrary to expectation, based on spatial relationships, spine numbers in A. quadracus and P. pungitius do not covary predictably over time. The results show that events at or near reproduction play a role in determining local morph frequencies. Our main finding is that spine number is surprisingly stable for both species, and we conclude that it is constrained to local equilibrium values.


1981 ◽  
Vol 59 (12) ◽  
pp. 2394-2395 ◽  
Author(s):  
Gérard J. FitzGerald ◽  
Jean-Denis Dutil

The diet of the black-crowned night heron (Nycticorax nycticorax) feeding in June and July along the southern shore of the St. Lawrence Estuary was composed primarily of the threespine stickleback Gasterosteus aculeatus. Three other sticklebacks, G. wheatlandi, Pungitius pungitius, and Apeltes quadracus occur in areas where the birds feed but were not eaten. It is suggested that differential predation on G. aculeatus may diminish interspecific competition for nest sites where the four stickleback species co-occur on the breeding grounds.


1973 ◽  
Vol 30 (3) ◽  
pp. 454-456 ◽  
Author(s):  
H. C. Freeman ◽  
D. A. Horne

In American eels (Anguilla rostrata) caught in Nova Scotia, the total mercury content was found to be 0.72 ± 0.05 ppm and the methylmercury content was 0.40 ± 0.06 ppm (mean ± SE for 23 fish). Since the mean total mercury content was less than 1 ppm and the toxic methylmercury content was 50% of this, or less than the 0.5 ppm guideline, such eels may be acceptable for human consumption.


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