Telestula humilis (Thomson, 1927) is a rare deep-sea stoloniferan octocoral distributed in the eastern Atlantic. Here we compared seven putative colonies of this species collected off Spain with the lectotype from the Oceanographic Museum of Monaco and found them to be identical morphologically. Phylogenetic analyses on both full mitogenomes and a concatenated alignment containing two mtDNA genes (mtMutS and Cox1) and nuclear 28S rRNA gene recovered Telestula humilis sister to Incrustatus and Inconstantia rather than to other species of Telestula. This therefore supports its taxonomic reassignment to Pseudotelestula gen. nov. as Pseudotelestula humilis comb. nov. The taxonomic reassignment is also supported by subtle differences observed between the morphology of the colony and the sclerome of Pseudotelestula humilis comb. nov. and the two sister genera. The occurrence of an intrusion tissue with sclerites in the basal part of the gastric cavity of the adult polyps is shared among Telestula and Pseudotelestula gen. nov. However, Pseudotelestula gen. nov. has sclerites arranged in a collaret and points below the tentacles, the sclerites of the calyx wall and the stolon are plump warty spindles, and the intrusion tissue has long sticks and spindles with cone-like spines.

Golden corals (chrysogorgiids sensu lato) are conspicuous components in deep-sea gorgonian assemblages. Although common, their taxonomy still conflicts with evolutionary histories, mostly due to low character availability and poor taxonomic knowledge. This is the case for the genus Pleurogorgia, which has been frequently reported in ROV surveys, dominating hard-bottoms throughout the Indo-Pacific. Herein, molecular phylogenetic reconstructions based on mitochondrial and nuclear datasets, and examination of new and old type material led us to suggest new systematic arrangements for some of the genera. We create a new genus, Ramuligorgia, to accommodate Pleurogorgia militaris, redescribing it as Ramuligorgia militaris comb. nov. within the family Chrysogorgiidae sensu stricto. Additionally, we describe Aurogorgia tasmaniensis gen. nov. et sp. nov., including it and the type species, Pleurogorgia plana, within Pleurogorgiidae fam. nov.

The routine use of DNA sequencing techniques and phylogenetic analysis has resulted in the discovery of many cryptic species, especially in the oceans. The common, globally introduced species Styela canopus is suspected to be a complex of cryptic species because of its widespread distribution and variable external morphology. We tested this possibility using COI and ANT marker sequences to uncover the phylogenetic relationship among 19 populations, and to examine genetic variability as well as gene flow. We obtained 271 COI and 67 ANT sequences and found surprising diversity among the 19 populations (COI: π = 0.18, hd = 0.99; ANT: π = 0.13, hd = 0.95). Corresponding topologies were found using Bayesian inference and maximum likelihood for both simple locus (COI) and multilocus (COI + ANT) analyses and so the clades received strong support. We used simple (ABGD, bPTP, GMYC) and multiple (BSD) locus methods to delimit species. The simple locus methods indicated that the current Styela canopus comprises at least 15 species. The BSD method for concatenated data supported 7 of the 15 species. We suggest that S. canopus should be treated as the Styela canopus complex. The large number of cryptic species found, often with more than one clade found in sympatry, creates opportunities for better understanding reproductive isolation, hybridisation or speciation. As several lineages have already been introduced widely around the world, we must quickly understand their diversity and invasive abilities.

The genus Obama Carbayo, Álvarez-Presas, Olivares, Marques, Froehlich & Riutort, 2013 currently comprises 41 species, most of them from Brazilian rainforests. This study describes three new species, viz. Obama autumnasp. nov., Obama leticiaesp. nov. and Obama aureolineatasp. nov., from remnants of Mixed Ombrophilous Forest in southern Brazil, based on an integrative approach and analyses their relationships within the genus. Obama autumna and O. aureolineata show distinctive colour patterns, contrasting yellow and black, which is unusual in species of the genus. The three species can be easily distinguished from their congeners by their external features and a combination of anatomical characteristics, such as the pharyngeal shape, shape and arrangement of the prostatic vesicle and anatomy of the penis papilla. The morphological hypotheses are corroborated by three species delimitation methods (ABGD, PTP and GMYC) and by phylogenetic analysis of the cytochrome c oxidase subunit I gene using maximum likelihood estimation and Bayesian inference. Furthermore, our phylogenetic analyses point out that Obama may be subdivided into three main clades, containing a variable number of well supported groups, the relationships of which remain unresolved. Obama autumna belongs to a distinct clade in relation to O. aureolineata and O. leticiae. Obama aureolineata belongs to one of the well supported groups, having a close relationship with O. apeva. Obama autumna may be more closely related to O. anthropophila and O. decidualis and O. leticiae to O. braunsi. However, the low nodal support does not allow the phylogenetic relationships of these species to be clearly established. We discuss morphological knowledge gaps in Obama, as well as issues regarding analyses based on molecular markers, which should be addressed to clarify relationships within the genus.

Leptonetidae are rarely encountered spiders, usually associated with caves and mesic habitats, and are disjunctly distributed across the Holarctic. Data from ultraconserved elements (UCEs) were used in concatenated and coalescent-based analyses to estimate the phylogenetic history of the family. Our taxon sample included close outgroups, and 90% of described leptonetid genera, with denser sampling in North America and Mediterranean Europe. Two data matrices were assembled and analysed; the first ‘relaxed’ matrix includes the maximum number of loci and the second ‘strict’ matrix is limited to the same set of core orthologs but with flanking introns mostly removed. A molecular dating analysis incorporating fossil and geological calibration points was used to estimate divergence times, and dispersal–extinction–cladogenesis analysis (DEC) was used to infer ancestral distributions. Analysis of both data matrices using maximum likelihood and coalescent-based methods supports the monophyly of Archoleptonetinae and Leptonetinae. However, relationships among Archoleptonetinae, Leptonetinae, and Austrochiloidea are poorly supported and remain unresolved. Archoleptonetinae is elevated to family rank Archoleptonetidae (new rank) and Leptonetidae (new status) is restricted to include only members of the subfamily Leptonetinae; a taxonomic review with morphological diagnoses is provided for both families. Four well supported lineages within Leptonetidae (new status) are recovered: (1) the Calileptoneta group, (2) the Leptoneta group, (3) the Paraleptoneta group, and (4) the Protoleptoneta group. Most genera within Leptonetidae are monophyletic, although Barusia, Cataleptoneta, and Leptoneta include misplaced species and require taxonomic revision. The origin of Archoleptonetidae (new rank), Leptonetidae, and the four main lineages within Leptonetidae date to the Cretaceous. DEC analysis infers the Leptoneta and Paraleptoneta groups to have ancestral distributions restricted to Mediterranean Europe, whereas the Calileptoneta and Protoleptoneta groups include genera with ancestral distributions spanning eastern and western North America, Mediterranean Europe, and east Asia. Based on a combination of biology, estimated divergence times, and inferred ancestral distributions we hypothesise that Leptonetidae was once widespread across the Holarctic and their present distributions are largely the result of vicariance. Given the wide disjunctions between taxa, we broadly interpret the family as a Holarctic relict fauna and hypothesise that they were once part of the Boreotropical forest ecosystem.

Among ∼1300 species of world nemerteans, seven species in five genera of lineid heteronemerteans have been known to possess a branched proboscis. In this paper, we describe the eighth branched-proboscis species: Gorgonorhynchus citrinus sp. nov. from Okinawa, Japan. We also report Gorgonorhynchus cf. repens Dakin & Fordham, 1931 with uniformly orange body, as a new member for the Japanese nemertean fauna. We infer the phylogenetic relationships between these forms and other members of Lineidae McIntosh, 1874 for which partial sequences of the mitochondrial 16S rRNA and cytochrome c oxidase subunit I, and the nuclear 18S rRNA, 28S rRNA, and histone H3 genes are available in public databases, along with newly sequenced data of another branched-proboscis heteronemertean, Polydendrorhynchus zhanjiangensis (Yin & Zheng, 1984) from China. In the resulting tree, Gorgonorhychus Dakin & Fordham, 1931 was sister group to non-branched-proboscis Dushia Corrêa, 1963, whereas P. zhanjiangensis was sister group to likewise non-branched-proboscis Cerebratulus lacteus (Leidy, 1851).