Seasonal Abundance and Age Composition of Two Populations of Culex Annulirostris (Diptera: Culicidae) at Darwin, Northern Territory, Australia

1986 ◽  
Vol 23 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Richard C. Russell
Keyword(s):  
Northern Territory ◽  
Seasonal Abundance ◽  
Age Composition ◽  
Culex Annulirostris ◽  
Two Populations

A Comparison of Sockeye Salmon Catches at Rivers Inlet and Skeena River, B.C., with Particular Reference to Age at Maturity

1958 ◽  
Vol 15 (3) ◽  
pp. 331-354 ◽  
Author(s):  
Harold Godfrey
Keyword(s):  
Sockeye Salmon ◽  
Environmental Influence ◽  
Size Variation ◽  
Age At Maturity ◽  
River Systems ◽  
Age Composition ◽  
Age Class ◽  
Skeena River ◽  
Two Populations

Age composition, size and sex data for sockeye salmon catches (1912–1954) at Rivers Inlet and Skeena River, B.C. were compared. For both river systems there were indications of 4- and 5-year cycles of abundance among the 4- and 5-year-old fish, respectively; but the two populations were not necessarily in phase. Tests for correlation between the numbers of parental and offspring fish strongly suggested the dominance of hereditary over environmental influence in determining age at maturity. The two stocks showed much similarity in annual size variation, among each sex and age-class.

Seasonal abundance of insect biocontrol agents ofMimosa pigrain the Northern Territory

2000 ◽  
Vol 39 (4) ◽  
pp. 328-335 ◽  
Author(s):  
Martin J Steinbauer ◽  
Penny B Edwards ◽  
Megan Hoskins ◽  
Tim Schatz ◽  
I Wendy Forno
Keyword(s):  
Northern Territory ◽  
Biocontrol Agents ◽  
Seasonal Abundance

Seasonal abundance, diel biting activity and parity of Aedes polynesiensis marks and A. samoanus (Grünberg) (Diptera: Culicidae) in Samoa

1987 ◽  
Vol 77 (2) ◽  
pp. 191-200 ◽  
Author(s):  
W. A. Samarawickrema ◽  
Fola Sone ◽  
R. F. Cummings
Keyword(s):  
Warm Season ◽  
Seasonal Abundance ◽  
Bancroftian Filariasis ◽  
Age Composition ◽  
High Rainfall ◽  
Daily Survival ◽  
Minor Peak ◽  
Aedes Polynesiensis ◽  
A Minor ◽  
Clear Relation

AbstractThe seasonal abundance, biting cycle, age composition and survival of females of Aedes polynesiensis Marks and A. samoanus (Grünberg), the major vectors of subperiodic bancroftian filariasis, were studied in Samoa. A. polynesiensis density was low during the high rainfall months and increased immediately following them. A. samoanus density showed no clear relation to rainfall. A. polynesiensis was active throughout the day, with peaks indoors and out at 08.00–09.00 h and 16.00–18.00 h. The nulliparous and parous populations showed similar patterns of activity. The biting cycles of 2-parous and 3- plus 4-parous females were asymmetric with time. A. samoanus was active throughout the night, with highest activity at 23.00– 01.00 h. A minor peak at 19.00–20.00 h was more pronounced among older females than among younger ones. Night biting by A. polynesiensis and day biting by A. samoanus were rare. The parous proportion of A. polynesiensis ranged from 36·3 to 59·5% and the epidemiologically significant 3- plus 4-parous proportion ranged from 1·0 to 6·7%. The parous proportion of A. samoanus was 37·9–49·7% and the 3- plus 4-parous proportion 1·4–2·6%. The proportions found to be parous in both vectors were generally higher in the cool than the warm season, suggesting higher daily survival during that period.

Specific status of Keratella cochlearis (Gosse) and K. earlinae Ahlstrom (Rotifera: Brachionidae): morphological and ecological considerations

1979 ◽  
Vol 57 (9) ◽  
pp. 1719-1722 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Vertical Distribution ◽  
Birth Rate ◽  
Recent Literature ◽  
Eutrophic Lake ◽  
Seasonal Abundance ◽  
Western Canada ◽  
Keratella Cochlearis ◽  
Stable Species ◽  
Shallow Eutrophic Lake ◽  
Two Populations

Keratella cochlearis and K. earlinae were found to coexist in a shallow eutrophic lake in western Canada. Differences between the two populations were found with respect to size, shape, seasonal abundance, birth rate, and vertical distribution. Results suggest that the two populations represent stable species and not ecophenotypes as suggested by recent literature.

Comparison of age composition, growth, and fecundity between two populations each of Fundulus heteroclitus and F. diaphanus (Pisces: Cyprinodontidae)

1975 ◽  
Vol 53 (4) ◽  
pp. 361-369 ◽  
Author(s):  
E. S. Fritz ◽  
E. T. Garside
Keyword(s):  
Growth Rate ◽  
Brackish Water ◽  
Fundulus Heteroclitus ◽  
Age Composition ◽  
Freshwater Environment ◽  
Weight Relationship ◽  
Two Populations ◽  
Banded Killifish

Age composition, growth rate, length–weight relationship, and fecundity comparisons were made among samples of two cyprinodontid fishes, the mummichog (Fundulus heteroclitus) and the banded killifish (F. diaphanus). from brackish water and freshwater sympatric and allopalric populations. Comparisons indicate that growth, both length and weight, of mummichog was not affected by habitation in weakly brackish water, but fecundity was reduced. However, both growth and fecundity of banded killifish were greater in brackish water than in a typical freshwater environment.

Demographic and reproductive attributes of dispersers in two populations of the subterranean rodent Ctenomys talarum (tuco-tuco)

1995 ◽  
Vol 73 (4) ◽  
pp. 732-738 ◽  
Author(s):  
Ana I. Malizia ◽  
Roxana R. Zenuto ◽  
Cristina Busch
Keyword(s):  
Sex Ratio ◽  
Body Mass ◽  
Litter Size ◽  
Age Composition ◽  
Subterranean Rodent ◽  
Ctenomys Talarum ◽  
Removal Studies ◽  
Two Populations ◽  
Experimental Plots ◽  
Subterranean Habitat

The demographic and reproductive characteristics of dispersers in the fossorial rodent Ctenomys talarum, the tuco-tuco, were studied by removing animals from two experimental plots. Data on dispersers' attributes were compared with those of resident and transient individuals from previous capture–mark–release and removal studies performed in the same localities. Average weekly dispersal by tuco-tucos was 2.38% (range 0–5.75%) at Necochea and 5.75% (range 0–15.75%) at Mar de Cobo. The low proportion of dispersers reflects their fossorial habit. At Mar de Cobo, the sex ratios of dispersers and transients showed a 1:1 relationship, whereas residents showed an excess of females. All groups did not differ from a sex ratio of 1:1 at Necochea. At both localities, dispersers did not differ qualitatively from residents in age composition, litter size, or body mass. Transients and dispersers of both populations were characterized by a higher proportion of immature individuals than residents. We conclude that dispersal may be an important factor regulating the C. talarum population and may counteract the restrictions imposed by its subterranean habitat.

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