Haplosyllis is a worldwide distributed genus of marine annelids, commonly associated with other invertebrates. Its characteristic simple bidentate chaetae have often led to mistakes in estimating the real diversity of the genus. Currently, Haplosyllis includes 38 species, nearly half of which inhabit the Indo‐West Pacific (IPW). Nevertheless, this number might be much higher given that some of the most common species in this a...

Approximately, 40% of earthworm species can reproduce by parthenogenesis. This is the case for the cosmopolitan species, Aporrectodea trapezoides , although sexual forms have been described sporadically. We analyse the genotypes and microbiomes of 30 individuals from four localities where both forms appear in order to understand the evolutionary mechanisms related to parthenogenesis. In all sites, heterozygosity values were ap...

Invasive species are one of the main threats to global biodiversity and, within marine ecosystems, tunicates feature some prominent examples. Styela plicata is an ascidian species inhabiting harbours in all temperate oceans and seas, thus being considered a thriving invasive species. However, this species' adaptive mechanisms, introduction history, and population structure have never been completely elucidated. Here, by genoty...

Population genomic studies have increased in the last decade, showing great potential to understand the evolutionary patterns in a great variety of organisms, mostly relying on RAD sequencing techniques to obtain reduced representations of the genomes. Among them, 2b-RAD can provide further secondary reduction to adjust experimental costs by using base-selective adaptors, although its impact on genotyping is unknown. Here we p...

Global environmental changes may have a profound impact on ecosystems. In this context, it is crucial to gather biological and ecological information of the main species in marine communities to predict and mitigate potential effects of shifts in their distribution, abundance, and interactions. Using genotyping by sequencing (GBS), we assessed the genetic structure of a keystone species in the Mediterranean shallow littoral ec...

Sponges have recently been proposed as ideal candidates to act as natural samplers for environmental DNA due to their efficiency in filtering water. However, validation of the usefulness of DNA recovered from sponges to reveal vertebrate biodiversity patterns in Marine Protected Areas is still needed. Additionally, nothing is known about how different sponge species and morphologies influence the capture of environmental DNA a...

Important changes in genetic relatedness may occur at extremely small scales in benthic invertebrates, providing key information about structuring processes in populations of these organisms. We performed a small‐scale study of the population structure of the sponge Crambe crambe , in which 177 individuals from the same rocky wall (interindividual distances from 0 to 7 m) were genotyped using six microsatellite markers. 101 sp...