Age and size at maturity can have significant fitness consequences. Selection often favors early-maturing individuals because of their higher survival to maturity and greater relative contribution to population growth rate, but it may also favor delayed maturation if fitness increases with age or size at maturity. Males of several poeciliid fishes exhibit variation in age and size at maturity p...

The main types of reproductive system structure, development and functions in cephalopods are described from personal observations and use of the literature. There is one type in males and three in females which are order specific. These have provided a basis for examining possible evolutionary trends in reproductive system development and in reproductive strategies within coleoid cephalopods a...

The interrelationships among five measures of physiologic maturity for 50 French-Canadian girls are evaluated--menarche, peak height velocity (PHV), 75% skeletal maturity, appearance of the ulnar sesamoid, and 90% dental development. The mean ages of occurrence of the events differed significantly (P less than 0.01). Menarche and 90% dental maturity showed the least variability. Ages of PHV, me...

Ratios of effective populations size, N(e), to census population size, N, are used as a measure of genetic drift in populations. Several life-history parameters have been shown to affect these ratios, including mating system and age at sexual maturation. Using a stochastic matrix model, we examine how different levels of persistent individual differences in mating success among males may affect...

Sexual dimorphism evolves when selection favors different phenotypic optima between the sexes. Such sexually antagonistic selection creates intralocus sexual conflict when traits are genetically correlated between the sexes and have sex-specific optima. Brown anoles are highly sexually dimorphic: Males are on average 30% longer than females and 150% heavier in our study population. Viability se...

Citation: Foley JR and Takahashi M (2017) Shell Lip Thickness Is the Most Reliable Proxy to Sexual Maturity in Queen Conch (Lobatus gigas) of Port Honduras Marine Reserve, Belize; Informing Management to Reduce the Risk of Growth Overfishing. Front. Mar. Sci. 4:179. doi: 10.3389/fmars.2017.00179 Shell Lip Thickness Is the Most Reliable Proxy to Sexual Maturity in Queen Conch (Lobatus gigas) of ...

Abstract We present a detailed histological study of long bones from an ontogenetic series Mussaurus patagonicus , early sauropodomorph the Lower Jurassic Argentina. Twenty bones, including humeri, femora and fibulae, obtained 13 individuals different body sizes were sampled for analysis. In general terms, cortical bone is formed by well vascularized fibrolamellar parallel fibred bone. Except s...