Nurse egg feeding and energy balance in embryos of Crepidula dilatata (Gastropoda: Calyptraeidae) during intracapsular development

Temperature-mediated plasticity and genetic differentiation in egg size and hatching size among populations of Crepidula (Gastropoda: Calyptraeidae)

Offspring size is a key characteristic in life histories, reflecting maternal investment per offspring and, in marine invertebrates, being linked to mode of development. Few studies have focused explicitly on intraspecific variation and plasticity in developmental characteristics such as egg size and hatching size in marine invertebrates. We measured over 1000 eggs and hatchlings of the marine ...

Effects of food availability on sex change in two species of Crepidula (Gastropoda: Calyptraeidae)

Sex allocation theory predicts that growth rates should influence the optimal size at sex change, with sex change occurring at larger sizes with increasing growth rates. We examined how variation in food availability affects growth rates and therefore influences size at sex change in 2 protandrous calyptraeid gastropods, Crepidula cf. marginalis and C. incurva. The lowest food concentration tes...

Effects of stress on sex change in Crepidula cf.marginalis (Gastropoda: Calyptraeidae)

Crepidula badisparsa sp. nov. (Gastropoda: Calyptraeidae) from Bocas Del Toro Province, Panama

—The taxonomy of calyptraeid gastropods is made difficult by their morphologically simple, plastic shells and the numerous instances of morphological convergence within the family. The small speckled species of Crepidula from the West Atlantic have all previously been referred to as C. convexa Say, 1822. Recent developmental and genetic work has shown that there are two species along the coast ...

the role of russia in transmission of energy from central asia and caucuses to european union

پس ازفروپاشی شوروی،رشد منابع نفت و گاز، آسیای میانه و قفقاز را در یک بازی ژئوپلتیکی انرژی قرار داده است. با در نظر گرفتن این منابع هیدروکربنی، این منطقه به یک میدانجنگ و رقابت تجاری برای بازی های ژئوپلتیکی قدرت های بزرگ جهانی تبدیل شده است. روسیه منطقه را به عنوان حیات خلوت خود تلقی نموده و علاقمند به حفظ حضورش می باشد تا همانند گذشته گاز طبیعی را به وسیله خط لوله مرکزی دریافت و به عنوان یک واس...