1 2 In teleost oocytes, yolk proteins (YP)-derived from the yolk precursors vitellogenins are 3 partially cleaved into free amino acids and small peptides during meiotic maturation prior to 4 ovulation. This process increases the osmotic pressure of the oocyte that drives its hydration 5 which is essential for the production of buoyant eggs by marine teleosts (pelagophil species). 6 However, th...

Seven species of fishes, Catostomus commersonii (Lacépède), Etheostoma nigrum Rafinesque, Micropterus dolomieu Lacépède, Notemigonus crysoleucas (Mitchill), Notropis hudsonius (Clinton), Perca flavescens (Mitchill), and Percina caprodes (Rafinesque) from the St. Lawrence River, Quebec, Canada, were found infected with progenetic specimens of Neochasmus spp. in the orbits and/or the body muscula...

In teleost oocytes, yolk proteins (YPs) derived from the yolk precursors vitellogenins are partially cleaved into free amino acids and small peptides during meiotic maturation before ovulation. This process increases the osmotic pressure of the oocyte that drives its hydration, which is essential for the production of buoyant eggs by marine teleosts (pelagophil species). However, this mechanism...

This study aimed to provide information about the reproductive biology of moonlight gourami (Trichopodus microlepsis) distributed in U Minh National Parks. Fish samples were collected monthly from January October 2019 at two locations: Ha (UMH, Ca Mau, n=462) and Thuong (UMT, Kien Giang, n=635). Results showed that maturation-stage ratios females similar between fish populations. Mature (with s...

1 Adult pine weevils Hylobius abietis emerge from conifer root-stumps, on which larvae develop, over an extended period during summer and autumn. Newly-emerged weevils were tested for their ability to fly and assessed for wing muscle and reproductive development. In addition, the effect of summer–autumn maturation feeding on reproductive development was assessed in field bioassays. 2 There was ...

younger birds laying slightly smaller eggs in each position within the laying sequence. Some physiological maturation process was probably responsible for the smaller eggs younger birds laid because the pattern held within individuals. However, changes in egg size and shape may be due to breeding experience rather than age itself. We detected no evidence for age-specific differences in egg size...

As first shown more than 100 years ago, fertilization of an aged (overripe) egg increases the rate of malformations and embryonic loss in several vertebrates, including possibly humans as well. Since the molecular events in aging eggs may be similar in these species, we established in the frog Xenopus tropicalis a defined protocol for delayed fertilization of eggs. A three-hour delayed fertiliz...