Size at 50% maturity (l50%) is commonly evaluated for wild populations as a point of biological reference (see Table 1). To estimate l50%, a sample of organisms known to have just reached sexual maturity could be available and their arithmetic mean size can be used as an estimator. However, the sample needed to obtain such a designbased estimator (Smith, 1990) for wild populations might be too ...

the current study investigated the effect of short-term selection for four week body weight (bw) on performance of divergent lines of japanese quail and their crosses. the mean of bw at hatching time, one, two, three and four week oldand bw at sexual maturity time, age at sexual maturity, number of eggs (from 50 to 100 days old), mean of egg weight, percentage of fertility and hatchability in e...

introduction: genetic and health factors along with ethnicity and geographic location are factors that affect the time of puberty onset. the aim of the present study was to evaluate the mean age of onset of puberty and its stages in boys of yazd. methods: this cross- sectional study with random clustering sampling method was conducted on 1018 healthy 9-16 years old male students of yazd. all ca...

The current study investigated the effect of short-term selection for four week body weight (BW) on performance of divergent lines of Japanese quail and their crosses. The mean of BW at hatching time, one, two, three and four week oldand BW at sexual maturity time, age at sexual maturity, number of eggs (from 50 to 100 days old), mean of egg weight, percentage of fertility and hatchability in e...

Twenty four farmed great sturgeon, Huso huso (including 8 males and 16 females) over 6 years old were used to develop a method for determination of sex and maturity stages. Seasonal gonadal tissue and blood samples were collected from farmed great sturgeon for three years. The sex and stages of maturity were determined by histology and laparoscopy at the beginning and end of experiment. Plasma ...

Size and age estimates at sexual maturity were determined for 162 male and 273 female little skates Leucoraja erinacea collected from the western Gulf of Maine. Maturity ogives suggest that 50% maturity in females occurs at age 9.5 years and 480 mm total length (LT), whereas 50% maturity in males occurs at a slightly younger age of 7.7 years and smaller size of 460 mm LT. Age estimates were mad...

This study aimed to characterize production and reproduction performances in Rhode Island Red-White strain chicken developed and maintained at the Central Avian Research Institute, Izatnagar. Three hundred and forty six fertile eggs were set in automated electric incubation and 234 chicks were investigated in three hatches. The performance data was analyzed by least squares analysis of variance...

Thresholds to sexual maturity—either age or size—are critical life history parameters. Usually investigated in short-lived organisms, these thresholds and interactions among age, size, and growth are poorly known for long-lived species. A 34-year study of captive green turtles (Chelonia mydas) that followed individuals from hatching to beyond maturity provided an opportunity to evaluate these p...

Twenty four farmed great sturgeon, Huso huso (including 8 males and 16 females) over 6 years old were used to develop a method for determination of sex and maturity stages. Seasonal gonadal tissue and blood samples were collected from farmed great sturgeon for three years. The sex and stages of maturity were determined by histology and laparoscopy at the beginning and end of experiment. Plasma ...