Data from: Taxonomy, biogeography and DNA barcodes of Geodia species (Porifera, Demospongiae, Tetractinellida) in the Atlantic boreo-arctic region

Geodia species north of 60°N in the Atlantic appeared in the literature
for the first time when Bowerbank described Geodia barretti and
G. macandrewii in 1858 from western Norway. Since then, a number of
species have been based on material from various parts of the region:
G. simplex, Isops phlegraei, I. pallida, I. sphaeroides, Synops
pyriformis, G. parva, G. normani, G. atlantica, Sidonops mesotriaena (now
called G. hentscheli), and G. simplicissima. In addition to these 12
nominal species, four species described from elsewhere are claimed to have
been identified in material from the northeast Atlantic, namely
G. nodastrella and G. cydonium (and its synonyms Cydonium muelleri and
Geodia gigas). In this paper, we revise the boreo-arctic Geodia species
using morphological, molecular, and biogeographical data. We notably
compare northwest and northeast Atlantic specimens. Biological data
(reproduction, biochemistry, microbiology, epibionts) for each species are
also reviewed. Our results show that there are six valid species of
boreo-arctic Atlantic Geodia while other names are synonyms or
mis-identifications. Geodia barretti, G. atlantica, G. macandrewii, and
G. hentscheli are well established and widely distributed. The same goes
for Geodia phlegraei, but this species shows a striking geographical and
bathymetric variation, which led us to recognize two species, G. phlegraei
and G. parva (here resurrected). Some Geodia are arctic species
(G. hentscheli, G. parva), while others are typically boreal
(G. atlantica, G. barretti, G. phlegraei, G. macandrewii). No
morphological differences were found between specimens from the northeast
and northwest Atlantic, except for G. parva. The Folmer cytochrome oxidase
subunit I (COI) fragment is unique for every species and invariable over
their whole distribution range, except for G. barretti which had two
haplotypes. 18S is unique for four species but cannot discriminate
G. phlegraei and G. parva. Two keys to the boreo-arctic Geodia are
included, one based on external morphology, the other based on spicule
morphology.