All genera of the world: Order Scorpiones (Animalia: Arthropoda: Arachnida)

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  All genera of the world: Order Scorpiones (Animalia: Arthropoda: Arachnida) Abstract The present contribution provides a consensus classification of the arachnid Order Scorpiones C.L. Koch, 1850, and updates the counts of extant and extinct genera and species through the end of 2025. Including the revisions implemented herein, there are 459 genus-group names available in Scorpiones by the end of 2025. Of these, 318 refer to currently accepted extant genera (220), subfossil genera (1) and extinct genera (97). Fifty-four genus-group names are newly synonymized, raising to 145 the number in synonymy, whereas sixteen genus-group names are revalidated and/or newly elevated to the rank of genus. Including the revisions implemented herein, Scorpiones includes 3,089 currently accepted species-group names (2,918 extant species, 1 subfossil species, and 170 extinct species) and 22 nomina dubia. Forty-seven species-group names are newly synonymized, whereas 43 species-group names are revali...

Tell Me How Much DNA You Have and I'll Tell You What Your Sex Is: Sex Determination by Flow Cytometry of Spiderlings of Allocosa marindia

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ABSTRACT

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Sex identification at early stages of development is of great interest for studies in evolutionary biology in many animals. Knowing the sex ratio, even more in offspring, allows testing hypotheses related to the cause of sex ratio biases in populations and species. Spiders born with a defined sex, mostly have an X1X20 sex chromosome system, but it is not possible to determine their sex phenotypically until the adult or near-adult stage. The wolf spider Allocosa marindia inhabits the sandy coast of Southern South America and shows sex role reversal. Laboratory and field studies suggest a strong bias in the sex ratio in favour of females in this species. Here, we analysed the 2C nuclear DNA content by flow cytometry in females and males of A. marindia to determine whether the difference between the sexes is enough to identify the sex of the individuals. The average 2C DNA content for females was 4.96 ± 0.036 pg and for males 4.72 ± 0.020 pg. Then, we tested the usefulness of the technique to sex A. marindia frozen spiderlings, in order to be able to decouple the collection time from the processing time. We analysed 59 spiderlings from four known females. Although we found greater variability in frozen samples, the difference in DNA content was enough to determine the sex of 54 frozen spiderlings (43 females and 11 males). Our results show a promising technique for sexing hatchlings of diplodiploid arthropods. In future studies, we will seek to sex spiderlings from a larger number of mothers to understand the causes of female bias in this species.

Bidegaray-Batista, L., N.Kacevas, F. F.Santiñaque, M.Vaio, and M.González. 2026. “Tell Me How Much DNA You Have and I'll Tell You What Your Sex Is: Sex Determination by Flow Cytometry of Spiderlings of Allocosa marindia.” Ecology and Evolution16, no. 4: e73453. https://doi.org/10.1002/ece3.73453.