Embryos of oviparous Reptilia (=turtles, lepidosaurs, crocodilians and birds) extract calcium for growth and development from reserves in the yolk and eggshell. Yolk provides most of the calcium to embryos of lizards and snakes. In contrast, the eggshell supplies most of the calcium for embryonic development of turtles, crocodilians and birds. The yolk sac and chorioallantoic membrane of birds ...

Palinurid lobsters are being exploited with increasing intensity in coral reef ecosystems, but marine protected areas may play a key role in preventing overfishing and local extinctions. In order to define the spatial requirements for protection, we compared the spatial and temporal patterns in distribution, density, biomass, size structure, and reproductive seasonality of Caribbean spiny lobst...

Se presentan nuevos registros de distribución para cuatro especies Clytini en los estados mexicanos Oaxaca y Chiapas. registra por primera vez la presencia Dexithea klugii (Castelnau & Gory, 1841) Placosternus crinicornis (Chevrolat, 1860) Oaxaca, guttatus Además, se proporcionan localidades erythropus 1835) Oaxaca. incluyen imágenes adultos sus mapas distribución.

Inbreeding in plants typically reduces individual fitness but may also alter ecological interactions. This study examined the effect of inbreeding in the mixed-mating annual Mimulus guttatus on visitation by pollinators (Bombus impatiens) in greenhouse experiments. Previous studies of M. guttatus have shown that inbreeding reduced corolla size, flower number, and pollen quantity and quality. Us...

—We examined vegetation characteristics around nest sites of the Hermit Thrush (Catharus guttatus) and Ovenbird (Seiurus aurocapillus) for three summers in the northernand mixed-hardwood forests of northern Wisconsin and the Upper Peninsula of Michigan to test the hypothesis that nests with greater concealment are less vulnerable to depredation. Because these two ground-nesting passerines diffe...

The risk imposed upon society by consumption of foods contaminated with metals and metalloids is an environmental problem attributed to the increasing number of mining extraction activities currently underway in Colombia. The aim of the current study was to determine concentrations of mercury (Hg), lead (Pb), cadmium (Cd), and a metalloid arsenic (As) found in the species of most consumed fish ...

Türkiye kıyılarından bildirilen yabancı balık türü sayısı 80'e ulaşırken, Ege Denizi 44'tür. Diğer taraftan, İzmir Körfezi'nden Lessepsiyen 15'tir. türleri sırasıyla Saurida lessepsianus, Lagocephalus sceleratus, Siganus rivulatus, S. luridus, Scomberomorus commerson, Bregmaceros nectabanus, Champsodon vorax, Etrumeus golanii, Stephanolepis diaspros, Nemipterus randalli, Upeneus moluccensis, He...