Phylum Bryozoa Ehrenberg, 1831 in the first twenty years of Zootaxa.

This short account is an invited contribution to the Zootaxa special volume 'Twenty years of Zootaxa.' Zootaxa was first published on 28 May 2001. Between this date and December 2020, 116 papers were published in Zootaxa that mention Bryozoa, comprising mostly descriptions of new species and higher taxa, but also including molecular sequencing (e.g. Fehlauer-Ale et al. 2011; Taylor et al. 2011; Franjevic et al. 2015), invasive-species research (e.g. Ryland et al. 2014; Vieira et al. 2014), checklists (e.g. Vieira et al. 2008), classification (e.g. Bock Gordon 2013), bryozoans as associates of other organisms (e.g. Rudman 2007; Chatterjee Dovgal 2020; Chatterjee et al. 2020), metazoan phylogeny (e.g. Giribet et al. 2013), biographies of historical figures who worked on bryozoans (e.g. Calder Brinkmann-Voss 2011; Calder 2015) and a catalogue of the fossil invertebrate taxa described by William Gabb (including 67 bryozoan species) (Groves Squires 2018). Of the 116 papers, 15 (13%) were open-access.

A genome-skimmed phylogeny of a widespread bryozoan family, Adeonidae.

BACKGROUND: Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes. Here, we use a genome-skimming approach to extract sequence information for 15 mitochondrial and 2 ribosomal operon genes from the cheilostome bryozoan family, Adeonidae, Busk, 1884, whose current systematics is based purely on morphological traits. The members of the Adeonidae are, like all cheilostome bryozoans, benthic, colonial, marine organisms. Adeonids are also geographically widely-distributed, often locally common, and are sometimes important habitat-builders. RESULTS: We successfully genome-skimmed 35 adeonid colonies representing 6 genera (Adeona, Adeonellopsis, Bracebridgia, Adeonella, Laminopora and Cucullipora). We also contributed 16 new, circularised mitochondrial genomes to the eight previously published for cheilostome bryozoans. Using the aforementioned mitochondrial and ribosomal genes, we inferred the relationships among these 35 samples. Contrary to some previous suggestions, the Adeonidae is a robustly supported monophyletic clade. However, the genera Adeonella and Laminopora are in need of revision: Adeonella is polyphyletic and Laminopora paraphyletically forms a clade with some Adeonella species. Additionally, we assign a sequence clustering identity using cox1 barcoding region of 99% at the species and 83% at the genus level. CONCLUSIONS: We provide sequence data, obtained via genome-skimming, that greatly increases the resolution of the phylogenetic relationships within the adeonids. We present a highly-supported topology based on 17 genes and substantially increase availability of circularised cheilostome mitochondrial genomes, and highlight how we can extend our pipeline to other bryozoans.