Temperature and Rate of Development of the Eggs of British Anura

10.2307/1483 ◽  
1948 ◽  
Vol 17 (2) ◽  
pp. 189 ◽  
Author(s):  
Roy Douglas
Keyword(s):  
Rate Of Development

Analysis of the rates of development and growth of Brachymystax lenok Savinovi during artificial reproduction by the industrial method

2020 ◽  
pp. 40-49
Author(s):  
S. Assylbekova ◽  
N. Badryzlova ◽  
L. Kushnikova
Keyword(s):  
Water Temperature ◽  
Fish Reproduction ◽  
Optimal Conditions ◽  
Artificial Reproduction ◽  
Fish Products ◽  
Rate Of Development ◽  
Stage Of Development ◽  
East Kazakhstan ◽  
Brachymystax Lenok ◽  
The Moment

The article presents the results of the first research on artificial reproduction in industrial conditions of the endemic, narrow-areal subspecies of Brachymystax lenok Savinovi, which lives in lake Markakol, East Kazakhstan region. The indicators of the heat sum characteristic for each stage of development, the rate of development and growth of the Markakolsky lenok from the moment of pre-breeding to late juveniles are described. To develop technological approaches for artificial fish reproduction, one of the most important points is to determine the optimal conditions for each stage and assess the risks (loss of fish products). At the stage of insemination and transportation of eggs to the place of incubation, the loss was 50 %. The largest losses of fish products were registered during the incubation stage. The most painlessly passed the period of holding and lifting on the float, where the loss was only 3 %. When growing pre-larvae and larvae in the pool, the daily waste did not exceed 1 %. Small-sized animals that were unable to adapt to artificial feeds fell into the waste. Losses during this period amounted to 15 % of the previous stage. In General, the yield of juveniles from the moment of fertilization to the end of the experiment was 16 %. The crucial factor in the development and growth of Lenok Markakolosky is the temperature regime. For the period of embryonic development, the most favorable water temperature is 7–8 °C. From the moment of hatching, the water temperature must be increased to 10–12 °C, and the optimal temperature for the cage growing of fingerlings varies from 12 to 14 °C.

Effects of rate of development of in vitro-produced ovine embryos on sex ratio and in vivo survival after embryo transfer

1997 ◽  
Vol 48 (8) ◽  
pp. 1369-1378 ◽  
Author(s):  
S.L. Catt ◽  
J.K. O'Brien ◽  
W.M.C. Maxwell ◽  
G. Evans
Keyword(s):  
Sex Ratio ◽  
Embryo Transfer ◽  
Rate Of Development

RATE OF DEVELOPMENT OF VIABILITY MUTANTS IN DROSOPHILA MELANOGASTER

Evolution ◽  
1957 ◽  
Vol 11 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Gert Bonnier ◽  
Ulla B. Jonsson
Keyword(s):  
Drosophila Melanogaster ◽  
Rate Of Development

Effects of Superparasitism on Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae)

1965 ◽  
Vol 97 (3) ◽  
pp. 326-331 ◽  
Author(s):  
H. G. Wylie
Keyword(s):  
Musca Domestica ◽  
House Fly ◽  
Food Shortage ◽  
Nasonia Vitripennis ◽  
Rate Of Development

AbstractSuperparasitism created a food shortage and thereby reduced survival and size of adult Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae) reared on pupae of the house fly, Musca domestica L. Superparasitism also reduced the percentage of females in the adult progeny but had no effect on rate of development, ability to emerge, or incidence of diapause in N. vitripennis.

The ecology of immature phases of trichostrongyle nematodes

Parasitology ◽  
1949 ◽  
Vol 39 (3-4) ◽  
pp. 274-280 ◽  
Author(s):  
H. D. Crofton
Keyword(s):  
Low Temperatures ◽  
Parasitic Disease ◽  
Larval Population ◽  
Rate Of Development ◽  
Pasture Contamination ◽  
Low Rate

Observations on the larvae of sheep trichostrongyles on hill pastures showed:1. A reduction in larval populations occurred when the ‘moving-flock’ type management was used. The large proportion of eggs passed in faeces is deposited on a part of the pasture where little or no grazing occurs.2. Local concentrations of larvae occurred on the grazed portions of a pasture when grazing was uneven. Thus, the apparent low rate of stocking on hill pastures does not give a true picture of the potential dangers of parasitic disease. Estimates of pasture contamination by Taylor's method of sampling were deceptively low.3. The number of larvae on grass blades was lowest when the grass was wet with dew. Sampling of pastures between 12 noon and 5 p.m g.m.t. gave maximal and most constant estimates.4. There was an increase in the number of larvae on a pasture during the warmer months of the year. While low temperatures prevent or delay hatching, the increase in population was not entirely due to the increased rate of development when temperature was high. The increase in numbers was partly due to an increase in the number of adult worms in the sheep hosts.5. Removal of sheep for 3 weeks reduced the number of larvae on a pasture. This reduction was not apparent, however, until after the first 12 days. After 3 weeks the pasture population was reduced by 55 %, while after 4 weeks (i.e. 7 days after the return of the sheep) the reduction was 90%. Two weeks later there was a small increase in the larval population, but this was again reduced with the onset of colder conditions.

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