Autogeny in Canadian Simuliidae (Diptera), with some experiments on rate of oögenesis

1990 ◽  
Vol 68 (11) ◽  
pp. 2429-2436
Author(s):  
D. M. Davies ◽  
H. Györkös
Keyword(s):  
Egg Production ◽  
Ovarian Development ◽  
Different Temperatures

Newly emerged females of 25 simuliid species were studied, 19 of which were maintained on dry sucrose and water to determine whether they could mature eggs autogenously. Females of nine species with reduced mouthparts and those of eight species with well-developed mouthparts proved to be autogenous, the latter group being presumably anautogenous for eggs cycles beyond the first. Females of the eight remaining species showed obligate anautogeny, requiring blood for any egg production. The literature indicated at least 19 Canadian simuliid species with obligate autogeny and at least 11 with facultative autogeny. The rate of ovarian development at different temperatures was examined in newly emerged females of 11 species and the completion of oögenesis varied from less than 2 days to 2 weeks in different species and in different females within species.

scholarly journals A gender bias in the calcification response to ocean acidification

2011 ◽  
Vol 8 (4) ◽  
pp. 8485-8513 ◽  
Author(s):  
M. Holcomb ◽  
A. L. Cohen ◽  
D. C. McCorkle
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Egg Production ◽  
Elevated Pco2 ◽  
Future Research ◽  
Astrangia Poculata ◽  
Population Structures ◽  
Different Temperatures ◽  
Increased Sensitivity ◽  
Ambient Co2

Abstract. The effects of nutrients and pCO2 on zooxanthellate and azooxanthellate colonies of the temperate scleractinian coral Astrangia poculata (Ellis and Solander, 1786) were investigated at two different temperatures (16 °C and 24 °C). Corals exposed to elevated pCO2 tended to have lower relative calcification rates, as estimated from changes in buoyant weights. No nutrient effect was observed. At 16 °C, gamete release was not observed, and no gender differences in calcification rate were observed. However, corals grown at 24 °C spawned repeatedly and male and female corals exhibited two different growth rate patterns. Female corals grown at 24 °C and exposed to CO2 had calcification rates 39 % lower than females grown at ambient CO2, while males showed only a 5 % decline in calcification under elevated CO2. At 16 °C, female and male corals showed similar reductions in calcification rates in response to elevated CO2 (15 % and 19 % respectively). At 24 °C, corals spawned repeatedly, while no spawning was observed at 16 °C. The increased sensitivity of females to elevated pCO2 may reflect a greater investment of energy in reproduction (egg production) relative to males (sperm production). These results suggest that both gender and spawning are important factors in determining the sensitivity of corals to ocean acidification and their inclusion in future research may be critical to predicting how the population structures of marine calcifiers will change in response to ocean acidification.

scholarly journals An investigation of the calcification response of the scleractinian coral <i>Astrangia</i> <i>poculata</i> to elevated <i>p</i>CO<sub>2</sub> and the effects of nutrients, zooxanthellae and gender

2012 ◽  
Vol 9 (1) ◽  
pp. 29-39 ◽  
Author(s):  
M. Holcomb ◽  
A. L. Cohen ◽  
D. C. McCorkle
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Scleractinian Coral ◽  
Egg Production ◽  
Elevated Pco2 ◽  
Future Research ◽  
Population Structures ◽  
Different Temperatures ◽  
Increased Sensitivity ◽  
And Gender

Abstract. The effects of nutrients and pCO2 on zooxanthellate and azooxanthellate colonies of the temperate scleractinian coral Astrangia poculata (Ellis and Solander, 1786) were investigated at two different temperatures (16 °C and 24 °C). Corals exposed to elevated pCO2 tended to have lower relative calcification rates, as estimated from changes in buoyant weights. Experimental nutrient enrichments had no significant effect nor did there appear to be any interaction between pCO2 and nutrients. Elevated pCO2 appeared to have a similar effect on coral calcification whether zooxanthellae were present or absent at 16 °C. However, at 24 °C, the interpretation of the results is complicated by a significant interaction between gender and pCO2 for spawning corals. At 16 °C, gamete release was not observed, and no gender differences in calcification rates were observed – female and male corals showed similar reductions in calcification rates in response to elevated CO2 (15% and 19% respectively). Corals grown at 24 °C spawned repeatedly and male and female corals exhibited two different growth rate patterns – female corals grown at 24 °C and exposed to CO2 had calcification rates 39% lower than females grown at ambient CO2, while males showed a non-significant decline of 5% under elevated CO2. The increased sensitivity of females to elevated pCO2 may reflect a greater investment of energy in reproduction (egg production) relative to males (sperm production). These results suggest that both gender and spawning are important factors in determining the sensitivity of corals to ocean acidification, and considering these factors in future research may be critical to predicting how the population structures of marine calcifiers will change in response to ocean acidification.

The Reproductive Capacity of the Larch Sawfly and Some Factors of Concern in its Measurement

1966 ◽  
Vol 98 (6) ◽  
pp. 561-578 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Egg Production ◽  
Ovarian Development ◽  
Fat Body ◽  
Adult Emergence ◽  
Individual Variability ◽  
Reproductive Capacity ◽  
Appreciable Effect ◽  
Larval Stages ◽  
Larch Sawfly ◽  
The Individual

AbstractOvarian development and egg production in the larch sawfly, Pristiphora erichsonii (Hartig), were studied in the development of a method for measuring reproductive capacity for population studies. Most of the oöcytes are mature at the time of adult emergence but some mature in the following few days. Quantitative differences in foliage consumption during the larval stages have an appreciable effect on egg production but normal environmental temperature differences and exposure to flooding during the spring development period influence ovarian development only to a limited extent.Reproductive capacity can be determined by oöcyte counts of dissected adults of uniform age. The sample size necessary for estimates of various degrees of precision was calculated.Several size measurements have a significant correlation with the numbers of oöcytes produced. The regression of numbers of oöcytes on adult weight is of limited usefulness in the estimation of reproductive capacity. This is largely due to the individual variability in the extent to which fat body tissue is utilized in ovarian development particularly in the case of the larger adults.

Effects of lighting program on reproductive development of female large white turkeys

1999 ◽  
Vol 79 (2) ◽  
pp. 149-155
Author(s):  
V. L. Melnychuk ◽  
F. E. Robinson ◽  
R. A. Renema ◽  
R. T. Hardin ◽  
D. A. Emmerson
Keyword(s):  
Egg Production ◽  
Ovarian Development ◽  
Reproductive Development ◽  
Day Length ◽  
Lower Body ◽  
Large White ◽  
Lower Body Weight ◽  
Younger Age ◽  
Mature Weight ◽  
Final Group

Female commercial turkeys were used to investigate the effects of lighting program on onset of egg production, reproductive development and egg production. Under a conventional (CON) lighting program, birds were photostimulated from 5L:19D to 14L:10D at 29 wk, with an additional hour of daylight added at 35 wk of age (15L:9D). The alternate (ALT) lighting program involved weekly 0.5 h decreases in day length from 14L:10D at 3 d to 6L:18D, at 17 wk followed by weekly 0.5-h increases in day length beginning at 20 wk, to a maximum of 15L:9D at 38 wk of age. Birds were killed either at 3-d intervals (140–206 d), to assess reproductive development, or on the day following the first oviposition. A final group of birds was maintained for egg-production records. The ALT birds reached first egg at a younger age (220 d vs. 224 d) and lower body weight (11.18 kg vs. 11.88 kg) than CON birds did. The oviduct of the CON treatment reached its mature weight 5 d before the ovary. The growing oviduct of the ALT birds reached its mature weight 4 d after the ovary. Ovarian development of the ALT birds was accelerated by 10 d, compared with that of the CON birds. The number of unreconciled ovulations, as evidenced by postovulatory follicles at first oviposition, did not differ between treatments (1.2, ALT; 1.6, CON). The number of large follicles was not different between the two treatments (12.9, ALT; 14.3, CON [P = 0.092]). First-egg weights were significantly lower (70.6 g, ALT; 77.2 g, CON) for the ALT treatment, which also had a higher incidence of small eggs for the first 4 wk of production (3.31%, ALT; 0.82%, CON). Total egg production and total settable egg-production did not differ between treatments. Key words: Turkey, sexual maturation, lighting program, ovary, oviduct

The influence of the host plant or males on ovarian development or oviposition in the diamondback moth Plutella maculipennis (Curt.)

1969 ◽  
Vol 47 (5) ◽  
pp. 805-816 ◽  
Author(s):  
R. J. Hillyer ◽  
A. J. Thorsteinson
Keyword(s):  
Egg Production ◽  
Host Plants ◽  
Ovarian Development ◽  
Broad Bean ◽  
Diamondback Moth ◽  
Larval Density ◽  
Allyl Isothiocyanate ◽  
Food Plants ◽  
Preoviposition Period ◽  
Prereproductive Period

The conditions of larval development, especially food quality and larval density, affected appreciably the length of the adult prereproductive period. The isolation of females from males after adult eclosion did not affect this prereproductive period but increased the preoviposition period. The presence of host tissue reduced the prereproductive period of adult females. Presence of non-host plants (wheat broad bean, and pea) did not significantly affect the length of the prereproductive period. The effect of the host on egg production was successfully simulated by exposing females to allyl isothiocyanate, a characteristic constituent of the food plants. The processes regulating number of eggs produced were discussed.

Pre-mating Blood Feeding by Anopheles pharoensis (Diptera: Culicidae) and Its Effects on Mating, Longevity and Egg Production

1990 ◽  
Vol 25 (1) ◽  
pp. 57-63
Author(s):  
Adel S. El-Akad ◽  
J. G. Humphreys
Keyword(s):  
Blood Meal ◽  
Egg Production ◽  
Ovarian Development ◽  
Reproductive Potential ◽  
Blood Feeding ◽  
Field Observations ◽  
Laboratory Studies ◽  
The Third ◽  
Anopheles Pharoensis ◽  
Blood Meals

Field observations and laboratory studies were conducted to determine the effects of a pre-mating blood meal on mating, ovarian development and oviposition in Anopheles pharoensis (Theobald). Approximately 24% of the females blood feed before mating; however, swollen abdomens of blood-fed females interfere with the mating process. In females which mated prior to first blood meal, first oviposition occurred at 6.6 days and required only a single blood meal. A second blood meal takes them to the second oviposition in an additional 2.5 days; the third oviposition required 1.4 blood meals and occurred 3 days after the second oviposition. Blood-fed unmated females reach first oviposition at 13.4 days and require an average of 4 blood meals prior to the first oviposition. At this age, the female is chronologically old and even if mating now occurs, egg production is greatly reduced and continues to decrease through subsequent ovipositions until death. The taking of a blood meal prior to mating greatly decreases the reproductive potential of this species.

scholarly journals EMBRYONIC DEVELOPMENT AND HATCHING EGGS RATIO OF BLACKSADDLED CORAL GROUPER (Plectropoma laevis) AT DIFFERENT TEMPERATURE MEDIA

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Wawan Andriyanto ◽  
Bejo Slamet ◽  
I Made Dharma Jaya Ariawan
Keyword(s):  
Embryonic Development ◽  
Egg Production ◽  
Incubation Temperature ◽  
Hatching Rate ◽  
Egg Hatchability ◽  
Different Temperatures ◽  
Hatch Success ◽  
C 30 ◽  
Hatching Eggs

In seed production, the success of spawning and egg production is very important to mantain the cultivating sustainability. The quantity and quality of the blacksaddled coral grouper eggs should be properly manipulated to produce the higher values. The purpose of this study was to determine the effect of different temperatures on the results of hatch success (embryo development, incubation time, hatching rate and larvae abnormality). The eggs used were obtained from natural spawning and collected with egg collector. The fertilized eggs were incubated in four pieces of container and were treated with different temperatures of 26°C, 28°C, 30°C, and 32°C which each treatment was repeated 3 times. The incubation equipment with automatic temperature control was used in this treatment. The results showed that the eggs which were incubated at 32°C produced a faster of embryonic development and hatch within 14 hours while the temperature of 26°C took 18 hours to hatch. However, the temperature of 32°C resulted in low egg hatchability, with 60.29%, as well as the abnormalities of 8.42%. The best temperature of each treatment was obtained at the incubation temperature of 30°C, whereas the phase of the hatch was achieved within 15 hours, with egg hatchability of 92.25% and the abnormality of 6.29%. From these results, it can be concluded that the optimum incubation temperature for Blacksaddled coral grouper was 30°C. Keywords: hatching, egg of Blacksaddled coral grouper, Plectropoma laevis, incubation temperature.

Observations on body proportions and egg production in the female parasitic copepod (Salmincola salmoneus) from the gills of Atlantic salmon (Salmo salar) kelts exposed to different temperatures and photoperiods

1987 ◽  
Vol 65 (2) ◽  
pp. 415-419 ◽  
Author(s):  
C. E. Johnston ◽  
D. Dykeman
Keyword(s):  
Low Temperature ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Egg Production ◽  
Parasitic Copepod ◽  
Body Proportions ◽  
Morphometric Measurements ◽  
Trunk Length ◽  
Reduced Body ◽  
Different Temperatures

A total of 651 adult female Salmincola salmoneus were removed from the gills of Atlantic salmon kelts exposed to four temperature and photoperiod regimes. A comparative analysis of body proportions and egg production was undertaken on copepod samples. Mean trunk lengths were significantly different between regimes, but trunk widths were only significantly different between low temperature and 12 °C regimes. Mean egg sac lengths, widths, egg numbers, and egg diameters were significantly different between low temperature and 12 °C regimes, but not between 12 °C regimes with different photoperiods. Photoperiod may have had an effect on trunk length, but not on any other morphometric measurements. Cool water temperatures significantly reduced body size and numbers of eggs and this may account for some of the differences in body proportions observed by other investigators.

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