Abstract Cladocerans are a diverse group of species that show rapid responses to changes in environmental conditions. This adaptive capacity has important implications for egg production and life cycle, especially transitory environments such as temporary waterbodies. The present study investigated the history Alona gutatta Sars, 1862 (Crustacea, Cladocera), an abundant frequent from high-altit...

Insect parasitoids and herbivores must balance the risk of egg limitation and time limitation in order to maximize reproductive success. Egg and time limitation are mediated by oviposition and egg maturation rates as well as by starvation risk and other determinants of adult lifespan. Here, we assessed egg load and nutritional state in the soybean aphid parasitoid Binodoxys communis under field...

1. Ovarian dynamics describe the highly complex interplay between egg maturation, oviposition, egg resorption and the factors affecting them. While these processes have been intensively studied, further progress has been impeded by the lack of generally applicable quantitative tools to analyse experimental data. 2. The purpose of this study is to provide a quantitative framework based on a stat...

Cytoplasmic poly(A) elongation is one mechanism that regulates translational recruitment of maternal mRNA in early development. In Xenopus laevis, poly(A) elongation is controlled by two cis elements in the 3' untranslated regions of responsive mRNAs: the hexanucleotide AAUAAA and a U-rich structure with the general sequence UUUUUAAU, which is referred to as the cytoplasmic polyadenylation elem...

The ridged swimming crab Charybdis natator (Portunidae) is a commercially important crustacean species in China. purpose of this study to compare its population structure and reproductive pattern within the same fishing area (the southern Taiwan Strait) from two datasets over 25 years; one 1994−1996 early years C. fishery) other 2019. overall sex ratio (male:female) changed male bias (1:0.76, p...

In oogenesis, meiosis must be highly regulated to ensure that growth of the oocyte and chromosomal segregation are coordinated properly. To do this, meiosis arrests at two points to permit oocyte differentiation and coordination with fertilization. In Drosophila, the first arrest in prophase I is released by oocyte maturation, and the second arrest in metaphase I is released by egg activation. ...

Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itaiçaba...

Evolutionary transitions among maternal, paternal, and bi-parental care have been common in many animal groups. We use a mathematical model to examine the effect of male and female life-history characteristics (stage-specific maturation and mortality) on evolutionary transitions among maternal, paternal, and bi-parental care. When males and females are relatively similar - that is, when females...

Osmolality and circulating levels of estradiol-17P, thyroxine, androgens, progesterone, and sodium are measured concomitantly with determination of oocyte maturation in coho salmon (Oncorhynchus kisutch) during the spawning season. Male and female salmon are held in both fresh water (their natural environment) and seawater (an unnatural environment) throughout the season. During the early stage...