scholarly journals Inflammation induced by faulty replication during embryonic development causes skewed sex ratio

2019 ◽  
Vol 101 (2) ◽  
pp. 259-261
Author(s):  
Zhuqing Wang ◽  
Wei Yan
Keyword(s):  
Sex Ratio ◽  
Embryonic Development

scholarly journals Sex Ratio, Fecundity and Morphometry of the Eggs of Freshwater Prawn Macrobrachium Americanum (Bate, 1868) in the Petatlán River, Sinaloa, Mexico

2021 ◽  
Vol 79 (1) ◽  
pp. 1-14
Author(s):  
Genaro Diarte-Plata ◽  
Ruth Escamilla-Montes ◽  
Salvador Granados-Alcantar ◽  
Antonio Luna-González
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Linear Model ◽  
Potential Model ◽  
Total Weight ◽  
Stage Ii ◽  
Freshwater Prawn ◽  
Spherical Form ◽  
Relative Fecundity ◽  
Egg Diameter

Abstract Macrobrachium americanum has a high commercial value with good fishing and cultivation possibilities in Mexico. Currently there is little information on reproductive aspects so the present work analyzed the sex ratio, fecundity and morphometry of the eggs of M. americanum in the Petatlán River, Sinaloa, Mexico. A total of 31 ovigerous females were captured. The sex ratio was 0.39 F: 1 M. The partial fecundity (Pf) varied from 34, 554 to 342, 372 eggs (128, 246 ± 12, 306 eggs, average Pf). The relationships between body and length-fecundity (R2= 0.5546), cephalothorax and length-fecundity (R2= 0.4995) were adjusted to a linear model, and the total weight-fecundity to a potential model (R2= 0.5013). The average relative fecundity was 37, 132 ± 5, 162 eggs/g. A total of 7 stages of embryonic development were observed. In the first stages, the egg presents a spherical form and in the latter an ovoid shape. Maximum egg diameter values are presented in stages VII, VI and VIII. Stage II provided the largest number of eggs (1, 013, 073 eggs). It is essential to optimize the exploitation of the population of M. americanum present in the Petatlán River through the creation of scientific bases for the sustainability of the fishery.

scholarly journals Reproductive biology and embryonic development of Centroscymnus coelolepis in Portuguese mainland waters

2003 ◽  
Vol 60 (6) ◽  
pp. 1335-1341 ◽  
Author(s):  
Ana Veríssimo ◽  
Leonel Gordo ◽  
Ivone Figueiredo
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Reproductive Biology ◽  
Sexual Maturity ◽  
Sampling Period ◽  
Yolk Sac ◽  
Pregnant Female ◽  
Reproductive Parameters ◽  
Reproductive Characteristics ◽  
Total Length

Abstract A total of 871 females (76–122 cm) and 86 males (68–100 cm) of Centroscymnus coelolepis caught in Portuguese mainland waters were examined for reproductive characteristics. One hermaphroditic individual of 95 cm was found. Males were few in numbers and dominated by immature specimens. Female length at first sexual maturity was 98.5 cm. Mean ovarian and uterine fecundity were 13.2 oocytes per female and 9.9 embryos per pregnant female, respectively. Total length of embryos with completely absorbed external yolk sacs ranged between 233 and 300 mm. Sex ratio (F/M) of embryos with completely absorbed external yolk sac was 0.9. All stages of reproduction were found during the 12-month sampling period. Results were compared with those from other regions. A hypothesis is formulated on the existence of several regional populations based on morphometric and reproductive parameters observed in different areas.

Reproductive biology of Orchestia gammarellus (Crustacea: Amphipoda) living in a sewage treatment works

1993 ◽  
Vol 73 (2) ◽  
pp. 405-416 ◽  
Author(s):  
M. B. Jones ◽  
G. D. Wigham
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Embryonic Development ◽  
Body Length ◽  
Life History Traits ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Sewage Treatment ◽  
Female Size ◽  
Egg Volume

A population of the supralittoral Orchestia gammarellus (Pallas) (Amphipoda: Talitridae), living in a percolating filter of a sewage treatment works has been studied over 12 months. The population showed a seasonal pattern of occurrence, few animals being collected during the winter. The sex ratio was biased significantly to females except during the breeding season when it did not deviate significantly from 1:1. Ovigerous females, never collected in high numbers (1–14 per month), were found from April to August, with peak occurrence in May/June. Juveniles were present throughout the year, but peak recruitment occurred in summer, following the period of reproduction by females. The smallest ovigerous female had a body length of 12.6 mm and the largest measured 20.0 mm. Egg numbers (5–31 per brood) increased with increasing female size and egg volume more than doubled during embryonic development. These findings are discussed in relation to the possible methods of colonization of this unique habitat and the influence of sewage on crustacean life-history traits.

Reproductive ecology of the velvet swimming crab, Necora puber (Brachyura: Portunidae), at Plymouth

1993 ◽  
Vol 73 (2) ◽  
pp. 379-389 ◽  
Author(s):  
C. P. Norman ◽  
M. B. Jones
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Brood Size ◽  
Swimming Crab ◽  
Egg Volume ◽  
The United Kingdom ◽  
South West ◽  
Near Shore ◽  
Brood Number ◽  
South West England

Monthly samples of intertidal and near-shore Necora puber were collected over two years from a commercially unfished area around Plymouth (south-west England). A clear reproductive cycle, consistent between the two years, was observed, and relatively high numbers of ovigerous females were found from January to June. Zoeal release was estimated to occur from April to June. Ovigerous females had developing ovaries, indicating that sequential broods occur. During embryonic development, egg volume increased by 109%, and egg loss was significant, accounting for between 14 and 18.5% of initial brood number. Females suffering limb loss showed a further reduced brood size compared to females with a full limb complement. The sex ratio of immature crabs was 1:1, whereas the ratio for mature crabs was biased to males (1.46:1). Two sperm plugs were observed in 90% of early postmoult mature females, but 10% had only one or no plug intact, suggesting their failure to mate successfully. These results are reviewed in relation to the biogeography of N. puber and with reference to the developing fishery in the United Kingdom.

Low-Temperature Protection of Marine Turtle Eggs During Long-Distance Relocation

1989 ◽  
Vol 16 (3) ◽  
pp. 317 ◽  
Author(s):  
JL Harry ◽  
CJ Limpus
Keyword(s):  
Low Temperature ◽  
Sex Ratio ◽  
Embryonic Development ◽  
Incubation Period ◽  
Temperature Regime ◽  
Loggerhead Turtle ◽  
Caretta Caretta ◽  
Early Embryonic Development ◽  
Marine Turtle ◽  
Long Distance

Movement of marine turtle eggs, between about 3 hours and 3 weeks after oviposition, often results in substantial embryonic mortality. Eggs of the loggerhead turtle (Caretta caretta), which were cooled to 7-10�C within a few hours of oviposition, were relocated 1077 km in 14 h before being set at temperatures within the normal incubation range (26, 28 and 32�C). The percentage of viable embryos and hatchlings produced from these eggs was comparable to that of undisturbed eggs laid in natural nests. The incubation period and the sex ratio of the hatchlings, observed for each temperature regime, were unaffected by the initial cooling. Cooling C. caretta eggs effectively arrests early embryonic development, thereby extending the period during which eggs can be relocated without causing movement-induced mortality. This procedure is applicable in situations where turtle eggs must be transported for research or hatchery management purposes.

scholarly journals Epidemiological Clinical and Profile of Cranio-spinal Dysraphisms in Madagascar

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Bemora Joseph Synèse ◽  
Andrianaivo Radotina Tony ◽  
Masina Ndalana d’Assise ◽  
Ratovondrainy Willy ◽  
Rabararijaona Mamiarisoa ◽  
...  
Keyword(s):  
Risk Factors ◽  
Folic Acid ◽  
Sex Ratio ◽  
Embryonic Development ◽  
Neural Tube ◽  
Congenital Malformations ◽  
Antenatal Diagnosis ◽  
Descriptive Study ◽  
Early Management ◽  
The Mean

Cranio-spinal dysraphisms are a set of congenital malformations resulting from a defect in closing the neural tube during embryonic development. The objective of this study was to describe the epidemiological-clinical profile of these malformations in Madagascar. It was a retrospective, descriptive study and metacentric from January 01, 2016 to December 31, 2018; all cases of cranio-spinal dysraphisms seen in two neurosurgery centers in Madagascar. We have collected 32 cases of cranio-spinal dysraphisms. The hospital prevalence was 0.37%. Among these children, the mean age was 8.48 months with an extreme of 1 day to 6 years; there was a feminine predominance (53,12%), with a sex ratio of 0.88. The absence of maternal intake of folic acid, the intake of folic acid outside the recommended periods, the birth order of the children and maternal pathologies during pregnancy were found as etiology. Cranial topography predominated in 56.25% (18 cases) and 68.75% of the children were asymptomatic. An association with hydrocephalus was found in 31.25% of cases. Prevention of known risk factors is essential, antenatal diagnosis is important for early management and improved prognosis. The treatment is surgical.

INFLUENCE OF THERMAL MANIPULATION DURING EMBRYONIC DEVELOPMENT ON HATCHABILITY TRAITS AND SECONDARY SEX RATIO OF BROILER CHICKS

2019 ◽  
Vol 39 (4) ◽  
pp. 825-833
Author(s):  
Ayat El-zeniny ◽  
Ahmed El-Kaiaty ◽  
Hewida El-Allawy ◽  
Hosam Safaa ◽  
Gamal Kamel ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Broiler Chicks ◽  
Secondary Sex Ratio ◽  
Thermal Manipulation

scholarly journals A note on the breeding season, sex ratio and embryonic development of the dogfish Scyliorhinus canicula (L.)

1952 ◽  
Vol 31 (2) ◽  
pp. 269-275 ◽  
Author(s):  
John E. Harris
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Breeding Season ◽  
Temperature Characteristic ◽  
Spawning Season ◽  
Spawning Ground ◽  
Teleost Species ◽  
Scyliorhinus Canicula ◽  
Different Temperatures

Records of nearly 2000 dogfish collected from the Ilfracombe region suggest that the spawning season of this fish starts in November and continues at least until July. This area probably represents a spawning ground into which the females migrate during the spawning season; the males follow them much later in April and May.Figures are given to show the time taken at different temperatures for the embryo to develop to a series of definite morphological stages; these suggest that the temperature characteristic of the development (µ = 20,000) is substantially the same as for several teleost species.

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