Reproductive potential of individual male Chinese mitten crabs Eriocheir japonica sinensis in a local pond-reared broodstock: Implications for parent crab selection and sex ratio optimization

2018 ◽  
Vol 49 (11) ◽  
pp. 3498-3507 ◽  
Author(s):  
Fujun Xuan ◽  
Xugan Wu ◽  
Naigeng Liu ◽  
Weibing Lu ◽  
Weibing Guan ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Reproductive Potential ◽  
Individual Male ◽  
Mitten Crabs ◽  
Eriocheir Japonica ◽  
Ratio Optimization ◽  
Eriocheir Japonica Sinensis

Studies of the Interaction Between Ciprofloxacin and the Hemocyanin From Chinese Mitten Crab Eriocheir Japonica Sinensis

2011 ◽  
Vol 44 (12) ◽  
pp. 2094-2106
Author(s):  
Hongmei Zhang ◽  
Boping Tang ◽  
Yanqing Wang ◽  
Daizhen Zhang ◽  
Huabin Zhang
Keyword(s):  
Chinese Mitten Crab ◽  
Mitten Crab ◽  
Eriocheir Japonica ◽  
Eriocheir Japonica Sinensis

scholarly journals Chromosome studies on the mitten crabs Eriocheir japonica and E. sinensis

2004 ◽  
Vol 70 (2) ◽  
pp. 211-214 ◽  
Author(s):  
Tai-Hung LEE ◽  
Nanami NAITOH ◽  
Fumio YAMAZAKI
Keyword(s):  
Mitten Crabs ◽  
Eriocheir Japonica

The sex ratio of a gilt’s birth litter can affect her fitness as a breeding female

2018 ◽  
Vol 58 (9) ◽  
pp. 1567 ◽  
Author(s):  
J. Seyfang ◽  
R. N. Kirkwood ◽  
A. J. Tilbrook ◽  
C. R. Ralph
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Reproductive Potential ◽  
Group Housing ◽  
Pork Industry ◽  
Welfare Issue ◽  
Breeding Herd ◽  
Uterine Environment ◽  
Animal Welfare Issue ◽  
Selection Of

Lifetime reproductive performance and behaviour are established in utero driven by genetics and the steroidal milieu of the uterine environment. Developing males synthesise androgens that can be absorbed by females in the litter. Consequently, the proportion of males in a litter has the potential to affect both lifetime reproductive performance and behaviour of female littermates. Although reproductive potential is understandably important for gilt selection, behaviour is becoming progressively more important as group housing of sows increases. Aggression can be a cause for removal from the breeding herd, and can also negatively affect reproductive performance and herd longevity. This review covers existing evidence of masculinisation in rodents and sheep, the mechanism causing masculinisation, and the knowledge gaps surrounding masculinisation in pigs. Premature culling of gilts is an economic and animal welfare issue in the pork industry resulting in low retention of gilts and reduced productivity. The selection of gilts needs to be improved to incorporate both lifetime reproductive potential and behaviour. We determined that there is cause to investigate the effect of the birth litter sex ratio of a gilt on her suitability for selection into the breeding herd.

scholarly journals Reproductive potential and nesting effects of Osmia rufa (syn. bicornis) female (Hymenoptera: Megachilidae)

2016 ◽  
Vol 60 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Karol Giejdasz ◽  
Monika Fliszkiewicz ◽  
Andrea Bednárová ◽  
Natraj Krishnan
Keyword(s):  
Sex Ratio ◽  
Reproductive Potential ◽  
Female Offspring ◽  
Male Offspring ◽  
Nesting Behavior ◽  
Solitary Bee ◽  
Male And Female ◽  
Individual Female ◽  
The Family ◽  
Number Of Cells

Abstract The red mason bee Osmia rufa is a solitary bee belonging to the family Megachilidae, and is prone to nest in aggregations. Each female builds a nest separately in pre-existing cavities such as holes in wood and walls or empty plant stems. This is done by successively setting the cells in a linear series. In this study, we elucidate the nesting behavior and the reproductive potential of a single O. rufa female. The reproductive potential of nesting females was evaluated after the offspring finished development. We observed that an individual female may colonize up to five nest tubes and build 5-34 cells in them (16 on an average). During the nesting time the number of cells decreased with the sequence of nest tubes colonized by one female, which built a maximum of 11 cells in the first occupied nest and 5 cells in the last (fifth nest). Our observations indicated that 40% of nesting females colonized one nest tube as compared to 7% colonizing five nest tubes. Furthermore, in subsequent nest tubes the number of cells with freshly emerged females gradually decreased which was the reverse with males. Thus, the sex ratio (proportion of male and female offspring) may change during the nesting period. The female offspring predominated in the first two nesting tubes, while in the subsequent three tubes male offspring dominated. We also cataloged different causes of reduction in abundance of offspring in O. rufa females such as parasitization or problem associated with moulting.

scholarly journals Egg production of Baltic cod (Gadus morhua) in relation to variable sex ratio, maturity, and fecundity

2002 ◽  
Vol 59 (12) ◽  
pp. 1908-1920 ◽  
Author(s):  
Gerd Kraus ◽  
Jonna Tomkiewicz ◽  
Friedrich W Köster
Keyword(s):  
Sex Ratio ◽  
Egg Production ◽  
Gadus Morhua ◽  
Reproductive Potential ◽  
Relative Fecundity ◽  
Spawning Stock ◽  
Class Strength ◽  
The Difference ◽  
Eastern Baltic ◽  
Baltic Cod

Observed fluctuations in relative fecundity of Eastern Baltic cod (Gadus morhua L.) were related to food availability during the main feeding period and were used to develop a predictive model that explained 72% of the interannual variations in fecundity. Time series of sex ratios, maturity ogives, and relative fecundity were combined with mean weights-at-age and stock sizes from an analytical multispecies model to estimate the potential egg production (PEP). Relationships between PEP and independent estimates of realized daily and seasonal egg production from egg surveys were highly significant. The difference between estimates of potential and realized seasonal egg production was of a magnitude corresponding to the expected loss of eggs as a result of atresia, fertilization failure, and early egg mortality. The removal of interannual variability in sex ratio, maturity, and fecundity on estimates of PEP deteriorated the relationships in all three cases. PEP proved to be superior to spawning stock biomass as measure of the reproductive potential in a stock-recruitment relationship of Eastern Baltic cod. PEP in combination with the reproductive volume explained 61% of the variation in year-class strength at age 2.

scholarly journals Variability of Selected Traits of Ips Typographus (L.) (Col.: Scolytinae) Populations In Beskid Żwiecki (Western Carpathians, Poland) Region Affected By Bark Beetle Outbreak

2014 ◽  
Vol 56 (2) ◽  
pp. 79-92 ◽  
Author(s):  
Wojciech Grodzki ◽  
Jerzy R. Starzyk ◽  
Mieczysław Kosibowicz
Keyword(s):  
Sex Ratio ◽  
Bark Beetle ◽  
Tree Mortality ◽  
Reproductive Potential ◽  
Ips Typographus ◽  
Spruce Stands ◽  
Gallery System ◽  
Infestation Density ◽  
Selected Traits ◽  
Very High

Abstract In 2010-2012, investigations on Ips typographus populations were carried out in Norway spruce stands recently affected by bark beetle outbreak in the Beskid Żywiecki Mts. in Poland. The aim of the study was to test the usefulness of several traits describing I. typographus populations for evaluation of their actual outbreak tendency. Infestation density, sex ratio, gallery length, progeny number and beetle length were used as the traits. Trait variability was analyzed in relation to infested tree mortality in the current year of observation and outbreak tendency defined by the comparison of data on tree mortality in the current year and that in the year before. The highest infestation density was found in the stands representing the highest tree mortality in the current year and in those characterized by decreasing outbreak tendency. The gallery system with 2 maternal galleries dominated. The sex ratio of attacking beetles inclined towards females (63.8%) and remained stable during 3 years of observations; the highest percentage of females was found in locations being in stabilization/latency outbreak phase. The length of maternal galleries was somewhat negatively affected by infestation density and positively correlated with the number of progeny in the gallery. The average beetle length was 4.800 mm (± 0.293), ranging between 3.718 and 5.817 mm and being the highest in the uppermost class of tree mortality recorded in the current year of observation. The shortest beetles were collected in the stands with increasing outbreak tendency, and slightly longer - in the stands with outbreak stable and decreasing tendencies. None of the traits tested can be selected as a direct indicator for prediction of outbreak tendency in I. typographus populations. Possible reasons of variability in the analyzed traits are discussed. The traits indicate that I. typographus in the study area represent very high reproductive potential, thus the risk of repeated outbreak is very high

scholarly journals Decline in body size and female fraction in the grass snake (Natrix natrix, Linnaeus 1758) population after 40 years (Southern Poland)

2021 ◽  
Author(s):  
Stanisław Bury ◽  
Bartłomiej Zając ◽  
Henryk Okarma ◽  
Aleksandra Kolanek
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Road Traffic ◽  
Prey Availability ◽  
Reproductive Potential ◽  
Environmental Pressures ◽  
Ambient Temperatures ◽  
Natrix Natrix ◽  
Resource Requirements ◽  
Grass Snake

AbstractDepletion of free-living populations is often associated with changes in fitness-related traits, e.g., body size. Ongoing decrease in body size has been reported in most vertebrates, but reptiles remain understudied. Moreover, sexual size dimorphism, commonly observed in reptiles, indicates that environmental pressures on body size may appear sex-specific. This can also result in shifts in sex ratio, an aspect even less studied. We investigated body size and sex ratio in population of grass snake (Natrix natrix) surveyed over 40 years ago in comparison with the current state. We found that both sexes express similar magnitude in body size decline. The current sex ratio does not deviate from 1:1, while in the past, females outnumbered males. The observed changes are likely an outcome of several non-mutually exclusive factors. In the studied area, an increase in road traffic and human presence and a drop in prey availability have been documented. Both factors may exert higher pressure on larger individuals, particularly females, due to their high costs of reproduction. It is recorded here that increase in ambient temperatures and summer duration may additionally enhance the mortality risk and resource requirements. Shifts in body size and sex ratio can catalyze further declines in abundance and reproductive potential of the population.

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