Preliminary observations on seasonal changes in prevalence and intensity of Cosmocercoides variabilis (Nematoda: Cosmocercoidea) in Bufo americanus (Amphibia)

1987 ◽  
Vol 65 (7) ◽  
pp. 1666-1667 ◽  
Author(s):  
Daryl J. Vanderburgh ◽  
R. C. Anderson
Keyword(s):  
Seasonal Changes ◽  
Early Spring ◽  
Fourth Stage ◽  
Bufo Americanus

Individuals of Bufo americanus were examined from April to October for the presence of Cosmocercoides variabilis (Harwood, 1930) Travassos, 1931. Fourth-stage larvae were present in lungs in late April to early May. Larvae found in lungs in spring migrated to the rectum and matured by the end of May. Transmission of C. variabilis probably occurs throughout the season. Larval and adult worms encountered in toads in early spring were probably acquired the previous year.

Seasonal changes in abomasal worms (Ostertagia spp.) in white-tailed deer (Odocoileus virginianus) at Long Point, Ontario

1975 ◽  
Vol 53 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Michael R. Baker ◽  
Roy C. Anderson
Keyword(s):  
Odocoileus Virginianus ◽  
Seasonal Changes ◽  
Abundant Species ◽  
Early Spring ◽  
Host Age ◽  
Fourth Stage ◽  
Domesticated Animals ◽  
Grazing Season

Three species of nematodes were recovered from the abomasa of white-tailed deer (Odocoileus virginianus) collected at Long Point, Ontario, from September 1972 to August 1973. Ostertagia odocoilei was recovered from 45 deer (96%), O. mossi from 31 (66%), and O. dikmansi from 30 (64%). Abundance of adult stages of all three species was greatest in summer and least in winter. O. odocoilei was the most abundant species, especially during winter. Females were more abundant than males at all times of the year, particularly during winter.Numerous inhibited early fourth-stage larvae were recovered during winter and early spring, while few were found in July and August. The decrease in numbers of inhibited larvae in spring was coincident with a corresponding increase in abundance of adult worms. This is the first indication of the existence of inhibition (previously reported in domesticated animals) in species of Ostertagia parasitizing deer. Inhibition was not related to host age, indicating that the phenomenon is probably not due to development of immunity by the host over the grazing season.

Seasonal changes in serum thyroid hormone levels in ruffed grouse maintained under natural conditions of temperature and photoperiod

1979 ◽  
Vol 57 (10) ◽  
pp. 2022-2027 ◽  
Author(s):  
A. Garbutt ◽  
J. F. Leatherland ◽  
A. L. A. Middleton
Keyword(s):  
Thyroid Hormone ◽  
Seasonal Changes ◽  
Gonadal Development ◽  
Early Spring ◽  
Light Period ◽  
Ruffed Grouse ◽  
Natural Conditions ◽  
Blood Samples ◽  
Serum Thyroid Hormone ◽  
Thyroid Hormone Levels

Serum triiodothyronine (T3) and thyroxine (T4) concentrations were measured in a population of ruffed grouse, held outdoors under natural conditions of photoperiod and temperature. Blood samples were collected at monthly intervals, and at the solstices and equinoxes to test for variation through the light period. No changes in T4 or T3 levels were found during the light period but levels of T3 and T4 showed marked seasonal changes. Lowest T4 and T3 levels were found in birds during the winter months, with an increase in the concentration of both hormones in early spring concomitant with gonadal development in the adults. A lowering of serum T4 and T3 values was associated with the period of molt.

Seasonal changes in concentrations of plasma hormones in the male ring dove (Streptopelia risoria)

1986 ◽  
Vol 108 (3) ◽  
pp. 385-391 ◽  
Author(s):  
R. W. Lea ◽  
P. J. Sharp ◽  
H. Klandorf ◽  
S. Harvey ◽  
I. C. Dunn ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Plasma Corticosterone ◽  
Early Spring ◽  
Energy Requirements ◽  
Breeding Cycle ◽  
Plasma Prolactin ◽  
Winter Solstice ◽  
Natural Lighting ◽  
Short Day ◽  
Ring Dove

ABSTRACT Seasonal changes in concentrations of plasma LH, prolactin, thyroxine (T4), GH and corticosterone were measured in captive male ring doves exposed to natural lighting at latitude 56 °N. Plasma LH levels decreased steeply in autumn when the daylength fell below about 12·5 h but increased in November as the birds became short-day refractory. In comparison with plasma LH concentrations in a group of short-day refractory birds exposed to 6 h light/day from the winter solstice, plasma LH levels in birds exposed to natural lighting increased further in spring after the natural daylength reached about 12·5 h. There were no seasonal changes in plasma prolactin concentrations and plasma T4 concentrations were at their highest during December, January and February, the coldest months of the year. The seasonal fall in plasma LH levels in September was associated with a transitory increase in plasma T4, a transitory decrease in plasma corticosterone and a sustained increase in plasma GH. It is suggested that in the ring dove, short-day refractoriness develops rapidly in November to allow the bird to breed when the opportunity arises, during the winter and early spring. The annual breeding cycle is synchronized by a short-day induced regression of the reproductive system in the autumn, the primary function of which may be to enable the birds to meet the energy requirements for the annual moult. The changes in plasma T4, corticosterone and especially of GH at this time of year are probably concerned with the control of moult or the associated changes in energy requirements. J. Endocr. (1986) 108, 385–391

The reproductive cycle of the viviparous seaperch, Cymatogaster aggregata Gibbons

1968 ◽  
Vol 46 (6) ◽  
pp. 1221-1234 ◽  
Author(s):  
John P. Wiebe
Keyword(s):  
Oocyte Maturation ◽  
Reproductive Cycle ◽  
Sertoli Cells ◽  
Reproductive Behavior ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Interstitial Cells ◽  
Early Spring ◽  
Seminiferous Tubules ◽  
Male And Female

The natural reproductive cycle of male and female Cymatogaster aggregata is described with reference to gametogenesis, development of secondary sex structures, reproductive behavior, and gestation. Spermatocytogenesis starts in early spring and by June or July clusters of spermatozoa fill the seminiferous tubules. Concurrently the Sertoli cells and interstitial cells of Leydig increase in size and secondary sex structures develop on the male anal fin. When the sexes mingle in summer, the males perform very elaborate reproductive behavior. Fertilization occurs about mid-December—5 months after mating—and the ovary is then modified to maintain the young embryos until parturition in mid-summer. Oocyte formation is highest in July and August, just after parturition, while vitellogenesis and oocyte maturation occur mainiy from October to December. These seasonal changes are discussed in relation to changes in environmental temperature and photoperiod.

The effect of plane of nutrition and shearing on the pattern of the moult in Scottish Cashmere goats

2002 ◽  
Vol 74 (1) ◽  
pp. 177-188 ◽  
Author(s):  
M. Merchant ◽  
D.J. Riach
Keyword(s):  
Seasonal Changes ◽  
Early Spring ◽  
Energy Requirements ◽  
Plasma Prolactin ◽  
Length Data ◽  
Cashmere Goats ◽  
Ad Libitum ◽  
Maintenance Requirements ◽  
Circulating Levels ◽  
Staple Length

AbstractThe effect of plane of nutrition on the timing of the moult in cashmere goats was investigated. Three groups of mature does were individually offered food to supply 0·8 (L, no. = 14), 1·2 (M, no. = 14) or 20 (H, no. = 13) times their estimated maintenance energy requirements from mid December until mid May. Two other groups of goats which were shorn in mid January, were offered 1·2 times maintenance requirements from mid December until mid March when food levels were increased to either 1·6 M (SL, no. = 6) or ad libitum (SAL, no. = 6). In mid May mean live weights for treatments L, M, H, SL and SAL were 36·0, 41·5, 46·9, 33·0 and 43·1 kg (average s.e.d. = 2·27, P < 0·001).The pattern of moult was described by changes in a subjectively assessed moult score, the proportion of follicles with brushes and staple length. The loss of brushes, indicating the start of the moult, began from the primary follicles on days 143, 131, 76, 150 and 129 (average s.e.d. = 13·5, P < 0001), and from the secondary follicles on days 141, 128, 104, 144 and 125 (average s.e.d. = 14·1, P = 0·053) for treatments L, M, H, SL and SAL respectively. The loss of brushes from primary and secondary follicles was completed on average, by days 194 and 206 of the experiment respectively, and there were no differences between treatments. Moult score and staple length data confirmed the conclusion that lowering the plane of nutrition delayed the start of the moult. No additional effect of fleece removal in the shorn treatments was observed.Changes in circulating levels of plasma prolactin, thyroxine, tri-iodothyronine, insulin, insulin-like growth factor-1 and growth hormone were related to seasonal changes in daylength and plane of nutrition. Their rôle in the control of the moult is discussed.Manipulation of the nutrition of cashmere goats in early spring has the potential to delay and increase the synchrony of fibre moult and to improve the efficiency of cashmere harvesting.

Seasonal variations in forms of extractable sulfur in some New Zealand soils

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 985 ◽  
Author(s):  
Z Tan ◽  
RG Mclaren ◽  
KC Cameron
Keyword(s):  
New Zealand ◽  
Seasonal Variations ◽  
Seasonal Changes ◽  
Early Spring ◽  
Continuous Increase ◽  
Organic C ◽  
The Third ◽  
Permanent Pasture ◽  
Low Levels ◽  
Inorganic Sulfate

Seasonal variations in different forms of extractable sulfur (S) were examined in three New Zealand soils under permanent pasture. The concentrations of total extractable S, extractable inorganic sulfate-S (SO2-4-S), and extractable organic HI-reducible sulfur (HI-S) and carbon-bonded sulfur (C-S) were determined in field moist samples using four different extractants. During the course of the year, extractable SO2-4-S levels varied substantially. Concentrations of SO42--S in the soils peaked in the early spring and, for two of the soils, remained at relatively low levels throughout the rest of the year. The third soil, however, following a decrease in concentration in late spring, showed a continuous increase in SO2-4-S during the summer and autumn period. Concentrations of extractable organic C-S in soils were generally highest in the winter and declined significantly during the spring. Extractable organic HI-S concentrations fluctuated throughout the year with no clear trends. The proportions of the three forms of extractable S in soils also varied seasonally. The proportions of extractable organic HI-S in soils were more constant compared with the other two forms of S and generally accounted for less than 20% of the total extractable S. The seasonal changes in the proportions of SO2-4-S appeared to be inversely related to the changes in extractable C-S. This suggests that under the field conditions, the extractable organic C-S fraction is readily mineralized to sulfate when conditions are favourable for mineralization to take place.

Seasonal changes in biomass and vertical distribution of mycorrhizal and fibrous-textured conifer fine roots in 23- and 180-year-old subalpine Abiesamabilis stands

1981 ◽  
Vol 11 (2) ◽  
pp. 224-230 ◽  
Author(s):  
Kristiina A. Vogt ◽  
Robert L. Edmonds ◽  
Charles C. Grier
Keyword(s):  
Root Growth ◽  
Vertical Distribution ◽  
Seasonal Changes ◽  
Forest Floor ◽  
Fine Roots ◽  
Early Spring ◽  
Silver Fir ◽  
Growing Up ◽  
Young Stand ◽  
Mycorrhizal Roots

Seasonal changes in biomass and vertical distribution of fibrous, mycorrhizal, and total conifer fine roots (≤ 2 mm) were examined in 23- and 180-year-old Pacific silver fir (Abiesamabilis (Dougl.) Forbes) ecosystems. In both stands, > 80% of fine roots was located in the upper 15 cm of the soil profile, in the forest floor (O1 and O2) and A horizon. During periods of active root growth in the young stand, significantly higher conifer root biomass occurred in the A horizon (370 to 690 g/m2) than the forest floor (200 to 350 g/m2). At all sampling times, a significantly higher biomass of conifer fine roots was located in the forest floor (550 to 1090 g/m2) than the A horizon (290 to 640 g/m2) in the old stand. In both stands, mycorrhizal roots comprised 10 to 15% of the total weight of conifer fine roots during peak root growth, 2 to 6% when roots were not growing, and 21 to 29% during the winter and early spring when roots were growing. Up to 69% of the biomass of fibrous and mycorrhizal roots was located in the forest floor in both stands.

Plasmatic protein values in captive adult Iberian red deer stags (Cervus elaphus hispanicus)

2010 ◽  
Vol 5 (5) ◽  
pp. 724-728
Author(s):  
Enrique Gaspar-López ◽  
Jose Estevez ◽  
Tomás Landete-Castillejos ◽  
Francisco Ceacero ◽  
Laureano Gallego ◽  
...  
Keyword(s):  
Cervus Elaphus ◽  
Seasonal Changes ◽  
Red Deer ◽  
Early Spring ◽  
Protein Electrophoresis ◽  
Blood Protein ◽  
Total Proteins ◽  
Mating Period ◽  
Cervus Elaphus Hispanicus ◽  
Iberian Red Deer

AbstractThe aim of this study was to assess the time trend of plasmatic proteins in red deer stags. Blood samples were taken monthly from 17 male red deer for 22 months. Total plasmatic determination and protein electrophoresis were performed. Plasmatic proteins showed minimum values during spring and summer and a maximum at the peak of the mating period. Total globulins, β and γ, followed a pattern similar to that observed for total proteins, whereas α1 and α2 globulins showed no seasonal variations. Albumin showed higher values in early spring and summer and lower values at the beginning of autumn, coinciding with the mating season. These seasonal changes in plasmatic proteins should be taken into account when assessing blood protein analysis results.

Influences of phenological differences on leaf-level carbon budget between the upper and lower crown of Lyonia ovalifolia

Botany ◽  
2013 ◽  
Vol 91 (1) ◽  
pp. 25-33 ◽  
Author(s):  
Kenichi Yoshimura
Keyword(s):  
Seasonal Changes ◽  
Carbon Budget ◽  
Construction Cost ◽  
High Light Intensity ◽  
Early Spring ◽  
High Light ◽  
Physiological Characteristics ◽  
Single Crown ◽  
Leaf Level ◽  
Light Acquisition

To assess the significance of leaf phenology on leaf-level carbon budget, I measured seasonal changes in daily carbon budget of the upper and lower leaves within a single crown of Lyonia ovalifolia var. elliptica, a subcanopy tree species. Leaf-level carbon budget was evaluated as the product of area-based assimilation rates and leaf area minus leaf construction cost for a day. The area of the upper leaves gradually increased from spring to summer, whereas that of the lower leaves rapidly increased in early spring. Morphological, biochemical and physiological characteristics in lower leaves matured earlier than in upper leaves. Leaves in the lower crown produced a large amount of photosynthate (1.35 mg C·day−1) using the high light intensity of early spring. On the other hand the highest assimilation rate (5.23 mg C·day−1) was observed in late spring in the upper crown. Phenological differences in morphological and physiological characteristics among leaves in different positions within a crown can be interpreted as the acclimation to the seasonal changes in light acquisition for a leaf.

Seasonal changes in the germination responses of seeds of Veronica peregrina during burial, and ecological implications

1983 ◽  
Vol 61 (12) ◽  
pp. 3332-3336 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Natural Habitat ◽  
General Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
Seasonal Temperature ◽  
Light In August ◽  
Late Autumn ◽  
Response To Temperature

Seeds of Veronica peregrina collected from a field population in central Kentucky were buried in soil and exposed to seasonal temperature changes. Fresh seeds and those exhumed after 1–26 months were tested in light and darkness at five thermoperiods simulating those in the natural habitat from early spring through late autumn. Freshly matured seeds were dormant, but they came out of dormancy in June and July and germinated to 98–100% in light in August at thermoperiods of 20:10, 25:15, 30:15, and 35:20 °C. Seeds retained the ability to germinate to high percentages at these temperatures until late winter and spring, but they never germinated to high percentages in darkness. Thus, in the natural habitat in July and August germination is prevented only by darkness and (or) insufficient soil moisture. At simulated habitat temperatures, seeds germinated to 88–100% in March and April but to only 21–69% in May and June. Seeds incubated at 15:6 °C showed a decline in germination percentages in late summer and autumn and an increase during late autumn and winter. The same general pattern of seasonal changes in germination response to temperature occurred during the 2nd year of burial.

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