Survival rates of the first and second offspring of Echthrodelphax fairchildii Perkins ( Hymenoptera : Dryinidae ) under self and conspecific superparasitism: The effects of body size of ovipositing females

2021 ◽  
Author(s):  
Weri Herlin ◽  
Hideto Yoshimura ◽  
Yoshihiro Y. Yamada
Keyword(s):  
Body Size ◽  
Survival Rates

The influences of pre- and post-smolt captive rearing environments on growth, maturation, body size, and reproductive success of steelhead (Oncorhynchus mykiss) released as adults.

2021 ◽  
Author(s):  
Donald M Van Doornik ◽  
Barry A Berejikian ◽  
Megan E Moore ◽  
Andrew Claiborne ◽  
Mark Downen ◽  
...  
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Oncorhynchus Mykiss ◽  
Age Differences ◽  
Survival Rates ◽  
Fish Population ◽  
Age At Maturity ◽  
Female Body Size ◽  
Rearing Conditions ◽  
Hatchery Program

Conservation hatcheries designed to aid in recovery of imperiled fish population often implement atypical rearing and release strategies. We evaluated a conservation hatchery program for steelhead (Oncorhynchus mykiss) that hydraulically removed naturally spawned eggs, and captively reared them in different freshwater hatcheries to the smolt stage, and reared smolts in both freshwater and seawater to sexual maturity, before releasing the sexually maturing adults onto the spawning grounds. The adult steelhead added to the spawning population, accounting for most of the adults observed during snorkel observations. They produced 32% of the juvenile offspring sampled, and females were 2.9 times more successful than males. Reproductive success was positively correlated with female body size, which was influenced by pre-smolt and post-smolt rearing conditions and their effects on growth rate and age-at-maturity. Juvenile offspring of the released adults showed size and age differences from offspring of naturally returning steelhead, but exhibited very similar early marine survival rates.

Seasonal Reproductive Patterns of Pumpkinseed (Lepomis gibbosus) Populations with Varying Body Size Characteristics

1994 ◽  
Vol 51 (3) ◽  
pp. 490-500 ◽  
Author(s):  
Andy J. Danylchuk ◽  
Michael G. Fox
Keyword(s):  
Body Size ◽  
Small Body ◽  
Gonadosomatic Index ◽  
Survival Rates ◽  
Significant Negative Correlation ◽  
Spawning Season ◽  
Lepomis Gibbosus ◽  
Reproductive Patterns ◽  
Adult Body Size ◽  
Adult Body

To assess the implications of reproduction on body size and the potential physiological constraint imposed by small body size on reproductive patterns, we examined seasonal nesting patterns and gonad allocation in six pumpkinseed (Lepomis gibbosus) populations exhibiting a range of adult body size characteristics, We found that the two populations exhibiting stunted adult body size initiated nesting activity 1-wk later and had nesting periods 3–7 wk longer than the other four populations. Mean adult body size showed a significant negative correlation with both length of spawning season and gonadosomatic index in the six populations. Within populations, smaller females matured later in the season than larger females. Our results suggest that small adult body size is associated with high reproductive effort and that variation in the timing of reproduction is a consequence of differences in energy reserves between small and large individuals. The extended spawning season of some populations may result in a higher cost of reproduction than that which would be predicted from gonad size alone. Small individuals forced by energy limitations to spawn late in the season are likely to produce offspring with lower survival rates, and their reproductive fitness should be discounted accordingly.

Inter-populational variations in body color related to growth stage and sex in Gaetice depressus (De Haan, 1835) (Decapoda, Brachyura, Varunidae)

Crustaceana ◽  
2015 ◽  
Vol 88 (1) ◽  
pp. 113-126 ◽  
Author(s):  
Yukiko Murakami ◽  
Keiji Wada
Keyword(s):  
Body Size ◽  
Field Experiments ◽  
Survival Rates ◽  
Color Difference ◽  
Color Pattern ◽  
Background Color ◽  
Body Color ◽  
Color Changes ◽  
Colored Background ◽  
Two Populations

The relative frequencies of color morphs in two populations of Gaetice depressus (De Haan, 1835) differed between size classes and sexes, the proportion of dark-colored crabs being greater in a habitat of dark colored cobbles, less where cobbles were light, indicating a conformance of G. depressus carapace color with background color. This difference between the two populations was apparent from the onset of the benthic stage. Field experiments demonstrated that a change in color proportion was greater on a dark-colored background compared to a light-colored background. However, a tethering experiment revealed no difference in the survival rate of young crabs of either color on either site, indicating that while body color difference between populations is attributable to the color pattern at settlement, the darkening of individual crabs on a dark-colored background was not due to different survival rates for individuals of different color patterns. As with carapace color in relation to body size, the proportion of dark-colored crabs was found to increase with increasing body size. Field and laboratory experiments demonstrated that light-colored crabs became darker with time, whereas dark-colored crabs exhibited little temporal change in body color. The proportion of dark-colored crabs was higher in females than in males, temporal color changes observed in the field also demonstrating that females became darker compared to males, irrespective of background color.

scholarly journals Morphology and Population Characteristics of Vancouver Island Cougars, Puma concolor vancouverensis

2004 ◽  
Vol 118 (2) ◽  
pp. 159
Author(s):  
Steven F. Wilson ◽  
Apryl Hahn ◽  
Aaron Gladders ◽  
Karen M. L. Goh ◽  
David M. Shackleton
Keyword(s):  
Body Size ◽  
Pacific Northwest ◽  
Puma Concolor ◽  
Survival Rates ◽  
Vancouver Island ◽  
Population Characteristics ◽  
Top Predator ◽  
Adult Females ◽  
The Pacific ◽  
Age And Sex

Cougars are a management concern on Vancouver Island because they are a top predator and because there have been frequent attacks on humans on the island. However, little is known about Cougar ecology in the Pacific Northwest of North America. We studied Cougar morphology and population characteristics as part of a larger study in two areas on Vancouver Island. We derived a multivariate measure of body size to describe changes with age and sex. Body size was similar in the two study areas. Survival rates for adult females were higher than those reported elsewhere; however, hunters avoided shooting females in general, and radio-collared Cougars in particular. Litter size at first detection was lower than reported in many other studies and may be related to food availability.Includes erratum for a figure in this article.

scholarly journals Immature development and survival of Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) on eggs of Tyrophagus curvipenis (Fain & Fauvel) (Acari: Acaridae)

Acarologia ◽  
2021 ◽  
Vol 61 (1) ◽  
pp. 84-93
Author(s):  
Guang-Yun Li ◽  
Nick Pattison ◽  
Zhi-Qiang Zhang
Keyword(s):  
Biological Control ◽  
Body Size ◽  
Prey Density ◽  
Food Source ◽  
Biological Control Agent ◽  
Survival Rates ◽  
Alternative Food ◽  
Neoseiulus Cucumeris ◽  
Supplementary Food ◽  
Significant Difference

Establishment and maintenance of the natural enemy are critical for successful biological control of pests on plants without alternative food for predators. Great efforts have been devoted to exploring suitable supplementary food for predators. In this study, we evaluated the feasibility of using Tyrophagus curvipenis (Fain and Fauvel) (Acari: Acaridae) as a supplementary food source for Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) by investigating the survival and development of N. cucumeris at different prey densities with the influence of conspecifics. Furthermore, we investigated predation rates and their body size at adult emergence. The results showed that N. cucumeris developed from egg to adult in approximately six days. Survival rates of immature predators increased significantly with the given prey density. No significant difference in body size was found between the survived adults fed at different prey density, but the females were always larger than males. To conclude, T. curvipenis can be an excellent alternative food source for the biological control agent N. cucumeris.

scholarly journals Atlantic salmon return rate increases with smolt length

2019 ◽  
Vol 76 (6) ◽  
pp. 1702-1712 ◽  
Author(s):  
Stephen D Gregory ◽  
Anton T Ibbotson ◽  
William D Riley ◽  
Marie Nevoux ◽  
Rasmus B Lauridsen ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Salmon ◽  
Survival Rates ◽  
Empirical Support ◽  
Return Rate ◽  
Imperfect Detection ◽  
Factors Affecting ◽  
Return Rates ◽  
Life Phase ◽  
Marine Survival

Abstract Recent declines in Atlantic salmon Salmo salar populations are generally attributed to factors in their marine life-phase. However, it is postulated that factors affecting their freshwater life-phase might impact their marine survival, such as the influence of body size. While larger smolts are widely hypothesized to have higher marine survival rates, empirical support remains scant, in part due to inadequate data and ambiguous statistical analyses. Here, we test the influence of smolt body size on marine return rates, a proxy for marine survival, using a 12-year dataset of 3688 smolts tagged with passive integrated transponders in the River Frome, Southern England. State-space models describe the probability of smolts surviving their marine phase to return as 1 sea-winter (1SW) or multi-sea-winter adults as a function of their length, while accounting for imperfect detection and missing data. Models predicted that larger smolts had higher return rates; the most parsimonious model included the effect of length on 1SW return rate. This prediction is concerning, as freshwater juvenile salmon are decreasing in size on the River Frome, and elsewhere. Thus, to maximize adult returns, restoration efforts should focus on freshwater life-stages, and maximize both the number and the size of emigrating smolts.

scholarly journals Body size, age structure and survival rates in two populations of the Beyşehir frog Pelophylax caralitanus

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 195-201 ◽  
Author(s):  
Ayşen Günay Arısoy ◽  
Eyup Başkale
Keyword(s):  
Body Size ◽  
Life Expectancy ◽  
Cross Sections ◽  
Age Structure ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Survival Rates ◽  
Adult Life ◽  
Lower Body ◽  
Two Populations

In many amphibians, skeletochronology is a reliable tool for assessing individual mean longevity, growth rates and age at sexual maturity. We used this approach to determine the age structure of 162 individuals from two Pelophylax caralitanus populations. All individuals exhibited Lines of Arrested Growth (LAGs) in the bone cross-sections and the average age varied between 4.5 and 5.4 years in both Işıklı and Burdur populations. Although intraspecific age structure and sex-specific age structure did not differ significantly between populations, we found that the Işıklı population had a lower body size in the same age class, had lower growths rates and lower values of survival rates and adult life expectancy than the Burdur population.

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

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