Annulus Formation on Scales of Four Species of Coregonids Reared Under Artificial Conditions

1968 ◽  
Vol 25 (10) ◽  
pp. 2111-2122 ◽  
Author(s):  
Walter J. Hogman
Keyword(s):  
Growth Rate ◽  
Metabolic Activity ◽  
Day Length ◽  
Lake Whitefish ◽  
Annulus Formation ◽  
Young Of The Year ◽  
Almost All ◽  
Coregonus Hoyi

Scales from known-age coregonids reared in the laboratory were examined to determine when annuli formed and to learn possible factors of their formation. Scales were taken monthly from marked fish for periods up to 21 months. Scales were also examined from fish that died and from preserved specimens of young-of-the-year for each species. Two marks formed on almost all scales each calender year. The stronger formed during March–April and the weaker in October–November. Both marks had all the usual characteristics of an annulus but the spring mark was considered the annulus and the fall mark an accessory check. The annulus formed during a period of constant temperatures and of little change in growth or increasing growth. The accessory check formed during a period of declining temperatures (1–5 degrees F, or 0.6–2.8 degrees C, per month) and of little change in growth or declining growth. Most fish grew throughout the winter; the only exceptions were one bloater (Coregonus hoyi) and several of the largest lake whitefish (C. clupeaformis). Fish were always given all the food they would eat to eliminate availability of food as a factor of mark formation. The temperature of the water during the winter (50 ± 0.3 F; 10.0 ± 0.2 C) did not arrest metabolic activity. The growth rate was related more closely to day length than to other variables examined.

Divergent Growth in Two Lake Whiteflsh (Coregonus clupeaformis) Populations

1973 ◽  
Vol 30 (11) ◽  
pp. 1683-1696 ◽  
Author(s):  
B. F. Bidgood
Keyword(s):  
Growth Rate ◽  
Growth Pattern ◽  
Fish Population ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Predator Prey ◽  
The Past ◽  
Population Reduction ◽  
Young Of The Year ◽  
Stable Growth

Divergence in the growth pattern of Pigeon Lake and Buck Lake whiteflsh (Coregonus clupeaformis) began during the winter months in young-of-the-year fish. The growth rate of individuals in the Pigeon Lake whitefish population has declined over the past 12 years whereas individuals in the Buck Lake population have maintained a relatively stable growth pattern. These differences did not appear to be genetically controlled. Increased interspecific and intraspecific competition for the available food supply likely suppressed the growth rate of the Pigeon Lake whitefish population. Reduction of predator numbers in Pigeon Lake by the removal of habitat and increased angling pressure accelerated recruitment to both the white-fish population and other competitive feeding forage fish. A predator–prey relationship conducive to the maintenance of a faster growing lake whitefish population has been maintained in Buck Lake over the same period of time.

Temperature Tolerance of Young-of-the-Year Lake Whitefish, Coregonus clupeaformis

1976 ◽  
Vol 33 (1) ◽  
pp. 177-180 ◽  
Author(s):  
Thomas A. Edsall ◽  
Donald V. Rottiers
Keyword(s):  
Temperature Tolerance ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Lethal Temperature ◽  
Young Of The Year ◽  
Coregonus Artedii ◽  
Coregonus Hoyi ◽  
Lake Herring

The ultimate upper lethal temperature of young-of-the-year lake whitefish, Coregonus clupeaformis, was 26.65 C; this value is closely similar to that reported for yearling bloaters, Coregonus hoyi (26.75 C) and young-of-the-year lake herring, Coregonus artedii (26.0 C).

scholarly journals The Influence of Maintenance Energy and Growth Rate on the Metabolic Activity, Morphology and Conidiation of Penicillium chrysogenum

1968 ◽  
Vol 50 (3) ◽  
pp. 399-412 ◽  
Author(s):  
R. C. RIGHELATO ◽  
A. P. J. TRINCI ◽  
S. J. PIRT ◽  
A. PEAT
Keyword(s):  
Growth Rate ◽  
Metabolic Activity ◽  
Penicillium Chrysogenum ◽  
Maintenance Energy

Detection of oomycide-insensitive Phytophthora isolates in Maryland ornamental nurseries and Mid-Atlantic landscapes provide data for reconsidering management strategies

2021 ◽  
Author(s):  
Justine Beaulieu ◽  
Johanna Del Castillo Munera ◽  
Yilmaz Balci
Keyword(s):  
Growth Rate ◽  
Mycelial Growth ◽  
Management Strategies ◽  
Resistance Management ◽  
Phytophthora Species ◽  
Oak Forests ◽  
Relative Growth ◽  
Off Label ◽  
Potting Media ◽  
Almost All

Five Phytophthora species comprising a total of 243 isolates (77 P. cinnamomi, 23 P. citrophthora, 18 P. multivora, 18 P. pini, and 107 P. plurivora) were screened for sensitivity to mefenoxam, fosetyl-Al, dimethomorph, dimethomorph + ametoctradin and fluoxastrobin using amended agar assays. Mefenoxam-insensitive isolates were detected within P. cinnamomi (4%), P. multivora (11%), and P. plurivora (12%) even at approximately 2.5x the recommended label rate. These isolates were also insensitive to higher (off-label) concentrations of fluoxastrobin. Concentrations of dimethomorph (400 g/mL) and dimethomorph + ametoctradin (100 g/mL) were mostly effective in mycelial growth inhibition, but two P. plurivora isolates were insensitive, suggesting that resistance management is required. All mefenoxam-insensitive isolates were sensitive to fosetyl-Al at the label rate. Surprisingly, the populations of P. cinnamomi from mid-Atlantic oak forests included insensitive isolates. With almost all species, isolates recovered from asymptomatic hosts (e.g., soil/potting media collected of randomly selected asymptomatic hosts) had a significantly greater relative growth rate when compared to isolates recovered from symptomatic hosts (e.g., isolates recovered from lesions or wilted plants). These findings suggest that mefenoxam should no longer be used to manage oomycetes in Maryland ornamental nurseries and that the use of fluoxastrobin should be limited.

The effect of supplementary light during winter on the growth, body composition and behaviour of steers and heifers

1997 ◽  
Vol 65 (2) ◽  
pp. 173-181 ◽  
Author(s):  
C. J. C. Phillips ◽  
P. N. Johnson ◽  
T. M. Arab
Keyword(s):  
Growth Rate ◽  
Body Composition ◽  
Food Intake ◽  
Day Treatment ◽  
Day Length ◽  
Fatty Tissue ◽  
Reduced Body ◽  
Entire Experiment ◽  
Female Cattle ◽  
Autumn And Winter

AbstractIn two experiments the growth, body composition and behaviour of steers and heifers kept in a building with natural day length only (average 9·7 h/day, treatment N) were compared with similar groups of animals kept in identical housing with the day length artificially extended to 16 h/day, (treatment L). The effects were recorded for 126 days in steers and 180 days in heifers, with both groups of animals being slaughtered in March when the two experiments ended. There were no effects over the entire experiment on the growth rate or food intake of either steers or heifers. The growth of the steers was reduced in the first 2 weeks after the lights were switched on but they gained more weight to compensate over the next 8 weeks. Over the whole experiment there was no treatment effect on food conversion ratio for either steers or heifers but it was reduced for steers on treatment L over the first 10 weeks. Steers in treatment N produced fatter carcasses than those on treatment L. Ultrasonic scanning of the heifers showed that those on treatment N deposited more fatty tissue between autumn and winter and less between winter and spring compared with those on treatment L.The behaviour of steers on treatment L did not vary over the experiment but steers on treatment N changed their behaviour with season. They slept for more time in winter and less in spring. Over the whole experiment steers on treatment L slept less and spent more time lying ruminating than those on treatment N but the total time spent lying was not affected by treatment. In contrast, the heifers on treatment L lay down for longer than those on treatment N, suggesting that the effect of supplementary light on lying time, which has been observed previously with dairy cows, is confined to female cattle. Heifers on treatment L started mounting each other earlier than heifers on treatment N and, like the steers, they spent less time sleeping It is concluded that extending the photoperiod for cattle in winter reduced body fatness in both steers and heifers and increased the time heifers spend lying down but that there were no major effects on growth rate or food intake.

Effects of ova transfer on the birthcoats of lambs

1972 ◽  
Vol 78 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Marca Burns
Keyword(s):  
Growth Rate ◽  
Meat Production ◽  
Transfer Experiment ◽  
Primary Follicle ◽  
Skin Expansion ◽  
Foetal Growth ◽  
Short Period ◽  
Selection For ◽  
Almost All ◽  
Size At Birth

SUMMARYBirthcoat samples from Lincoln and Welsh Mountain lambs born in an ova transfer experiment (Weiner & Slee, 1965) were examined to determine the fibre type arrays and any effect of ova transfer on manifestation of the prenatal check or the base (Dry, 1965).In the Lincoln breed arrays were Truncated Ravine or Truncated Valley thus showing central checking. Pre-curly tip fibres were mainly confined to central primary follicles. Post-natal medullation was plentiful, especially in peak curly-tips, but kemp was absent. In the Welsh lambs all identifiable arrays were either Plateau or Saddle, with the lateral primary fibres more checked than the centrals. Pre-curly tip fibres occupied almost all the primary follicles, with only a few curly-tips in primary laterals. Post-natal medullation was strongest in pre-curly tips and their successors.The effect of ova transfer was to decrease the manifestation of check in Lincoln-in-Welsh and increase it in Welsh-in-Lincoln, without affecting the base. Although this, in each case, changed the check of the lamb in the direction of that of the foster breed, it is suggested that this may not be due to any influence of maternal check on foetal check. The effect on pre-natal check may be due to foetal size, and in particular skin expansion, during a short period immediately following completion of primary follicle initiation. As compared to their respective controls, the Welsh transfer lambs had a higher S/P ratio at birth, whilst that of the transferred Lincolns was reduced.If increased prenatal fibre check is associated with increased foetal growth rate at the relevant period, it may also be correlated with increased lamb size at birth and therefore have been favoured in selection for meat production, at least in some breeds.

Water Relations of Beans I. Effects of Water Stress on Growth and Flowering

1969 ◽  
Vol 5 (3) ◽  
pp. 195-207 ◽  
Author(s):  
A. H. El Nadi
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Water Stress ◽  
Plant Growth ◽  
Relative Growth Rate ◽  
Broad Bean ◽  
Day Length ◽  
Vegetative Period ◽  
Relative Growth ◽  
Made In

SummaryExperiments were made in glasshouses, growth cabinets and growth rooms to study the differential responses of the broad bean to water stress during the vegetative and flowering phases of growth. Plants in the flowering phase proved to be more sensitive to drought than in the vegetative period, and there were different responses (Relative Growth Rate) to temperature at different stages of plant growth. Day length and temperature influenced the position of the earliest flower initials on the stem, and intensity of flower shedding was aggravated by high temperature.

High Growth Rate of Young-of-the-year Smallmouth Bass in Lake Erie: a Result of the Round Goby Invasion?

2004 ◽  
Vol 30 (3) ◽  
pp. 381-389 ◽  
Author(s):  
Geoffrey B. Steinhart ◽  
Roy A. Stein ◽  
Elizabeth A. Marschall
Keyword(s):  
Growth Rate ◽  
Lake Erie ◽  
Round Goby ◽  
High Growth ◽  
High Growth Rate ◽  
Smallmouth Bass ◽  
Young Of The Year
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