Stimuli associated with copulatory behavior are often needed to maximize reproductive output in internally fertilized sexual taxa. Although non-pseudogamous parthenogenetic females have no need for sperm, parthenogens descended from sexual ancestors may still require copulatory stimuli to reach their full reproductive potential. Retention of physiological dependence on copulation in parthenogen...

The meaning of alternative biotests is described and discussed. The paper also deals with the possible application of the developmental studies of the sea Artemia franciscana nauplinus. Five-day biotests including the validation criteria are described. The possibilities of the biotests are very wide. Additionally to the standard applications in ecotoxicology, there is a possibility of modelling...

Darevskia rock lizards include both sexual and parthenogenetic species, mostly distributed in the heterogeneous and ecologically diverse Caucasus. The parthenogenetic species originated via directional hybridogenesis, with only some of the sexual species known to serve as parentals. However, it remains unclear when and where these events happened and how many parental lineages were involved. A ...

Data were collected on the down color of 1,386 parthenogenetic embryos and poults from eggs of 306 young virgin and older nonmated bronze turkey hens. Each hen involved was heterozygous (Cc) for alleles which affect feather pigmentation. Six hundred and sixty nine white and 717 colored parthenogenetic embryos and poults were observed, a 1:1 ratio. Subsequently, 89 of these 306 heterozygous bron...

Parthenogenesis, a natural form of asexual reproduction produced from unfertilized eggs, occurs in many insects in Hemiptera and Hymenoptera, but very rarely in Lepidoptera. The current study aimed to test the larval density dependent occurrence of parthenogenesis in potato tuber moth, Phthorimaea operculella (Zeller; Lepidoptera: Gelechiidae) under laboratory conditions. More than 10% of femal...

Background: Prior research on the microorganisms associated with the brine shrimp, Artemia franciscana, has mainly been limited to culture-based identification techniques or feeding studies for aquaculture. Our objective was to identify bacteria and archaea associated with Artemia adults and encysted embryos to understand the role of microbes in the Artemia life cycle and, therefore, their impo...

long term monitoring programme on brine shrimp ( artemia sp.) is being carried out by the environment agency, abu dhabi, united arab emirates (ead) with the prime purpose of understanding the population dynamics, ecology and habitat requirements of artemia at al wathba lake, situated within al wathba wetland reserve, which is an artificial wetland near abu dhabi city. the present study, being a...

One explanation for the success of sexual reproduction is that sex increases the efficacy of natural selection. Recombination and segregation lead to fitness variance among offspring which then offers a wider target for natural selection. Consequently, adaptation to changing environments is accelerated and population mean fitness will increase. We investigated whether low levels of sex are asso...

Die Zusammensetzung und der Stoffwechsel der Carotinoide in adulten Exemplaren von Artemia salina wurden untersucht. Unabhängig von der Fütterung mit carotinoidfreier Hefe, mit an Oxicarotinoiden reicher Nahrung oder mit Oxocarotinoid-haltigen Algen lassen sich als Hauptpigmente Canthaxanthin (4.4'-Dioxo-/?-carotin) und Echinenon (4-Oxo-/?-carotin) nachweisen. Daneben wur­ den in einer Artemia-...

http://dx.doi.org/10.1016/j.anbehav.2014.12.017 0003-3472/© 2014 The Association for the Study of A Parthenogenesis is an asexual mode of reproduction that is rare in nature compared to sex. Parthenogenetic animals are derived from sexual progenitors, but little is known about how transitions to parthenogenesis evolve and persist. One hypothesis is that selection promotes transitions to parthen...