An attempt was made to provide some vital aspects of reproductive biology of cobia Rachycentron canadum (Linnaeus, 1766). Samples for a period of two years from an exploratory vessel and from the landing centers of Mumbai were used for the study. The average sex ratio between males and females observed was 1:0.80. Dominance of the number of females above the size of 100 cm was noticed. The size...

Two studies using commercially fed cattle were conducted to determine the relationship of the USDA bone ossification-based maturity system to one based on the number of permanent incisors present at slaughter. These studies showed that 91.5 to 100% of cattle with zero permanent incisors (< 23.8 mo of age), 89.1 to 97.5% of cattle with two permanent incisors (23.8 to 30.4 mo of age), 75 to 82.2%...

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...

Wild and domesticated Atlantic salmon males display large variation for sea age at sexual maturation, which varies between 1-5 years. Previous studies have uncovered a genetic predisposition for age at maturity with moderate heritability, thus suggesting a polygenic or complex nature of this trait. The aim of this study was to identify associated genetic loci, genes and ultimately specific sequ...

  Estimates of age, growth parameters, length-weight relationship and length and age at first maturity of the otolithes ruber are required for fishery management. We used counting annuli on the section of sagittal otoliths to age O.ruber from the Northwest Persian Gulf in south of Iran. Estimated ages ranged from 0 to 6 years, and maximum frequency of fishes was observed in age-group 1. The val...

The Norwegian spring-spawning herring (Clupea harengus) population collapsed to the state of commercial extinction in the late 1960s; the stock remained at extremely low levels for over two decades, but has recovered fully since the 1980s. It is known that the collapse coincided with strong changes in maturation characteristics. However, the long-term patterns of maturation in this stock have r...

Fifty-one ewes, 50 wethers and 51 rams of Finn x whiteface or Suffolk x whiteface breeding were slaughtered at an average age of 271, 361, 459, 557 or 652 d to study changes in maturity characteristics with changes in age. When metacarpal epiphyseal cartilage (growth plates) ossifies with age, break joints on the distal end of the metacarpals fuse and the end of the bone then appears as a spool...

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...

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...