Quelques aspects de la biologie du grand corégone Coregonus clupeaformis des lacs Hélène et Nathalie, territoire de la Baie James

1978 ◽  
Vol 56 (6) ◽  
pp. 1402-1411 ◽  
Author(s):  
Pierre Dumont ◽  
Réjean Fortin
Keyword(s):  
Life History ◽  
Population Density ◽  
Water Temperature ◽  
Growth Rates ◽  
Aquatic Insects ◽  
Coregonus Clupeaformis ◽  
Main Food ◽  
Food Items ◽  
Relative Fecundity ◽  
History Of

The life history of lake whitefish in lakes Nathalie (53°27′ N; 77°27′ W) and Hélène (53°27′ N; 77°31′W) was studied between June 1974 and November 1975. The age of 840 specimens was determined from the scales. Growth rates are very slow, compared only with those of dwarf whitefish of certain North American lakes. Food varies with the length of the fish and with the season of the year. Main food items are aquatic insects (larvae and adults), mollusks, and small fishes. In 1975, spawning occurred in late October (water temperature: 4 °C), at depths of 2–4 m; substrates utilized were sand, gravel, and boulders. Spawning lasted less than 2 weeks. Males mature at 390 mm (age 8) and females at 400 mm (age 9). Lake Nathalie whitefish (N = 41) show a low relative fecundity (17 980 eggs/kg). In the fall of 1974, the population density of Lake Nathalie whitefish 350 mm and longer was estimated at 839 individuals (0.72 kg/ha).

Observations on Phaeosaccion collinsii in culture

1971 ◽  
Vol 49 (4) ◽  
pp. 563-566 ◽  
Author(s):  
J. McLachlan ◽  
L. C.-M. Chen ◽  
T. Edelstein ◽  
J. S. Craigie
Keyword(s):  
Life History ◽  
Nova Scotia ◽  
Water Temperature ◽  
Spore Germination ◽  
Light Intensities ◽  
History Of ◽  
Single Locality

The life history of Phaeosaccion collinsii Farlow, a species which is known from a single locality in Nova Scotia, has been completed in culture. There was no indication of a sexual phase and zoospores gave rise directly to the tubular thallus. Completion of the life history occurred at 5 °C only. At higher temperatures spores failed to germinate, or growth and differentiation were suppressed. Light intensities exceeding 100 ft-c inhibited spore germination, although growth and differentiation were not similarly affected. In nature mature plants occur sublittorally, and are present only in spring when the water temperature is around 5 °C. Zoospore flagellation is of the typical heterokont type with the flimmer bearing bilateral hairs. On this basis P. collinsii can be placed either in the Chrysophyceae or Phaeophyceae.

Life history of two burrowing aquatic insects in southern Europe: Leuctra geniculata (Insecta: Plecoptera) and Ephemera danica (Insecta: Ephemeroptera)

2009 ◽  
Vol 31 (2) ◽  
pp. 99-110 ◽  
Author(s):  
Manuel J. López-Rodríguez ◽  
J. Manuel Tierno de Figueroa ◽  
Javier Alba-Tercedor
Keyword(s):  
Life History ◽  
Aquatic Insects ◽  
Southern Europe ◽  
History Of ◽  
Ephemera Danica

The life history of Branchinecta mackini Dexter (Crustacea: Anostraca) in an argillotrophic lake of Alberta

1977 ◽  
Vol 55 (1) ◽  
pp. 161-168 ◽  
Author(s):  
Graham R. Daborn
Keyword(s):  
Organic Matter ◽  
Life History ◽  
Life Cycle ◽  
Growth Rates ◽  
Dry Weight ◽  
Fairy Shrimp ◽  
Maximum Biomass ◽  
History Of ◽  
Mean Size

The life history of B. mackini was studied in a large argillotrophic lake during 1970–1972. Hatching began immediately after spring thaw and was terminated by rising salinity 10 days to 2 weeks later. Growth rates reached maxima of 1 mm/day at 4 weeks of age and then declined as mean size approached 22–23 mm at 7–8 weeks. Clutch sizes varied as a function of female length. Maximum biomass of 580 mg dry weight/m2 (2700 cal/m2) was reached in late May, of which 3.9% per day was consumed by B. gigas. Source of the energy is presumed to be a bacteria – organic matter complex associated with suspended particles. Life cycle details are compared with other fairy shrimp species and the role of B. mackini in the community is discussed.

Dynamics of an Exploited Population of Lake Whitefish (Coregonus clupeaformis)

1977 ◽  
Vol 34 (7) ◽  
pp. 942-953 ◽  
Author(s):  
Graham Bell ◽  
Paul Handford ◽  
Carl Dietz
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Age Structure ◽  
Annual Rate ◽  
Multiple Regression Equation ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
History Of ◽  
Almost All ◽  
Key Words Population Dynamics

The life history of the exploited lake whitefish (Coregonus clupeaformis) population of Lesser Slave Lake, Alberta, is described. Mean age is high, having increased under continued exploitation during the last 30 yr. A method of estimating the population age structure is described. The apparent annual rate of survival of adult fish has fluctuated markedly, but on average seems to lie in the interval 0.40–0.50; the annual rate of natural survival is estimated to be 0.53. Juveniles survive better than adults. Rate of survival during the 1st yr of life was estimated to be about 0.0002. Maturity was late, the median age at first reproduction being 6–61/2 yr. The regressions of fecundity on age and length are described; length now contributes almost all the attributable variance to maturity and fecundity. The sex ratio fluctuates in time; this is caused by the fluctuations in age structure, since sex ratio varies with age. The relationship between sex ratio and age is used to calculate the relative rates of survival of male and female fish.These data are used to construct a life table and to compute population parameters. It is inferred that the ability of the population to respond to exploitation has been eroded during the last 30 yr. In some respects, the life history of the Lesser Slave Lake stock appears to be unusual.After about 30 yr of large-amplitude oscillation the whitefish population collapsed in 1965. This does not seem to have been caused by chronic overfishing. In the first place, the rate of fishing mortality is no more than moderate. Secondly, a multiple regression equation describing whitefish catch in 48 other Alberta lakes in which there has been no overall decline in catch successfully predicts the observed mean catch at Lesser Slave Lake. The oscillations in catch are claimed to reflect a limit cycle in the abundance of the whitefish, driven by a lagged relationship between a predator (the fishermen) and its prey (the whitefish). Whether or not this cycle was deterministically stable, such behavior will inevitably put the population in risk of extinction during troughs in the cycle. We suggest that current management policies may encourage the destabilization of whitefish populations, and we propose a remedy. Key words: population dynamics, population regulation, life history, exploitation, survival, fecundity, Coregonus clupeaformis

Further Observations on the Life-history of Limnaea truncatula

Parasitology ◽  
1926 ◽  
Vol 18 (2) ◽  
pp. 144-147 ◽  
Author(s):  
C. L. Walton ◽  
W. Norman Jones
Keyword(s):  
Life History ◽  
Growth Rates ◽  
Egg Masses ◽  
Three Generations ◽  
Spring Generation ◽  
History Of

1. Egg masses of Limnaea truncatula collected in March 1925 were isolated and hatched in the Laboratory. The average number of ova per mass (for 20) proved to be 9·75.2. The hatching period lasted 12 to 26 days, with an average of 20–21 days (for the Spring generation).3. On hatching, young snails were isolated, reared, and again oviposited during the first week of July. Ova from these snails again hatched during the first week of August.4. It is thus shown that L. truncatula is self fertile; that oviposition can commence at a shell altitude of 4 to 4·5 mm.5. Further data on growth-rates were obtained, showing that two (and probably three) generations occur between March and October.

scholarly journals EFFECTS OF SAND BAR GEOMORPHOLOGY AND WATER TEMPERATURE ON LIFE HISTORY OF CLAM IN THE BANJO ESTUARY

2005 ◽  
Vol 49 ◽  
pp. 1357-1362
Author(s):  
Satoquo SEINO ◽  
Makoto HIGASHINO ◽  
Tohru TAKAMI ◽  
Hanae HIRASHIMA ◽  
Yoshiaki NAKASHIGE ◽  
...  
Keyword(s):  
Life History ◽  
Water Temperature ◽  
History Of ◽  
Sand Bar

scholarly journals Life history of Capnia bifrons (Newman, 1838) (Plecoptera: Capniidae) in a small Apennine creek, NW Italy

2013 ◽  
Vol 24 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Bo Tiziano ◽  
Manuel Jesús López-Rodríguez ◽  
Alessandro Mogni ◽  
Josè Manuel Tierno de Figueroa ◽  
Stefano Fenoglio
Keyword(s):  
Organic Matter ◽  
Life History ◽  
Secondary Production ◽  
Flight Period ◽  
Ontogenetic Shift ◽  
Coarse Particulate Organic Matter ◽  
Food Items ◽  
Mountain System ◽  
History Of ◽  
Nw Italy

The biology of stoneflies from Apennine mountain system is little known. In the present study, we provide information on the life cycle, secondary production, nymphal feeding and flight period of <i>Capnia bifrons</i> (Newman, 1838) in the Albedosa creek (NW Italy). At this study site, the species has a univoltine life cy- cle, with a relatively short and fast nymphal development period and high annual secondary production. Nymphs feed mainly on detritus but incorporate also other food items in their diet, such as coarse particulate organic matter and fungi. Ontogenetic shift from collector-gatherer to shredder habits is detected. Emer- gence is in February–April, slightly late compared to northern populations.

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