Nest site has influence on incubation duration and hatching success of two Neotropical turtles, the giant Amazon River turtle (Podocnemis expansa) and yellow-spotted side-neck turtle (Podocnemis unifilis--'Tracajá'). The 2000 and 2001 nesting seasons have been monitored at the Javaés River in Bananal Island, Brazil. Although they nest on the same beaches, there is a separation of the nesting ar...

Of the seven sea turtle species, the critically endangered leatherback sea turtle (Dermochelys coriacea) exhibits the lowest and most variable nest success (i.e., hatching success and emergence success) for reasons that remain largely unknown. In an attempt to identify or rule out causes of low reproductive success in this species, we established the largest sample size (n = 60-70 for most valu...

To determine the in vitro effects of various environmental and nutritional factors on the hatching of eggs, development and survival of larvae of Oesophagostomum columbianum, eggs were cultivated at different temperature gradients, humidity and P in phosphate buffer saline (PBS), tap water (TW) and normal saline (NS) using serum and liver extract at different concentrations during the period fr...

1. Synchrony in the timing of births is thought to have evolved as a general predator avoidance strategy. In turtles, synchronous hatching may facilitate group emergence from the nest, which in turn, may limit predation by diluting an individual’s risk of predation or by simply swamping predators upon emergence. However, synchronizing hatching should not be easily achieved in natural nests beca...

Abstract:  The optimum dose of UV irradiation to produce gynogenesis rainbow trout, Oncorhynchus mykiss with emphasis of Hertwing effect and photoreactivation (PR) was investigated. For this purpose, the sperm of rainbow trout were inadiated with UV at 2010±200 µw.cm-2 intensity in different alternatives of 0, 1, 3, 5, 8, 10, 15, 20, 25, 35 and 45 minutes and allowed to ferti...

Crocodilians are known to vocalize within the egg shortly before hatching [1,2]. Although a possible function of these calls - inducing hatching in siblings and stimulating the adult female to open the nest - has already been suggested, it has never been experimentally tested [1-5]. Here, we present the first experimental evidence that pre-hatching calls of Nile crocodile (Crocodylus niloticus)...

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The main objective of this study was to elucidate the effect of short- term exposure of Japanese quail eggs to acute high incubation temperature on embryonic development and on the ability of post- hatched chicks to cope with subsequent heat stress conditions during the growing period. A total of 998 Japanese quail eggs were divided into two groups, the first group (470 eggs) was maintained at ...