Arturia Azevedo et al., 2017

Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, Zootaxa 4426 (1), pp. 1-160 : 22

Genus Arturia Azevedo et al., 2017

Remarks. Our Calcinea phylogeny ( Figs 2, 2A, 2C ) shows a peculiar discrepancy in the affiliation of the two species of Arturia we found in our collection of Calcarea from the Western Indian Ocean. A. sueziana ( Klautau & Valentine, 2003) is grouped on its own in Figs 2 and 2C outside any of the Calcinean genus and family clades, whereas A. adusta ( Wörheide & Hooper, 1999) ended up close to the main group of Clathrina species. We investigated which of the two species is closest to the type species of Arturia , i.e. A. hirsuta ( Klautau & Valentine, 2003) , by downloading the available GenBank 18S sequences of Arturia species, because apart from Voigt et al. ’s (2017) 28S rRNA sequences and our own, there are no other Arturia sequences of that gene in GenBank. The 18S sequences of the type species (accession numbers KC843431 & KC985143 ), of A. sueziana ( KY366410 ), of Clathrina adusta (AM 180962), of two additional unnamed Arturia species ( KC985141 & KC985142 ), of Ernstia tetractina, of Clathrina sinusarabica Klautau & Valentine, 2003 ( KY366407 ), and of Leucetta floridana Haeckel, 1872 ( KC843456 ) were analyzed with the MEGA package.The result (not shown) clearly confirmed that A. sueziana is close to the type species A. hirsuta and the two unnamed Arturia , near Leucetta floridana , and that Clathrina adusta did not group with these, but ended up separately and nearer to Clathrina sinusarabica and Ernstia tetractina. In our Fig. 2A it is demonstrated that Arturia adusta is joined by the Indonesian Arturia tubuloreticulosa Van Soest & De Voogd, 2015 and Arturia angusta (Van Soest & De Voogd, 2015) (transferred here, but originally as Ascaltis ). We are not proposing a new genus for this second Arturia group, but we confirm Voigt et al. ’s (2017) suggestion that the Ernstia - Arturia relationships need to be analyzed further, not only molecularly, but also morphologically. The morphological characters provided by Klautau et al. (2013) fail to give sufficient support for recognition of three Clathrina -like generic taxa with tetractines, Ernstia, Arturia s.s. and ‘ Arturia ’.

Figures

FIGURE 2. Maximum-likelihood tree based on analysis of sequences of the partial 28S gene (C2–D2 region, comprising 442 sites) of Western Indian Ocean Calcinea newly generated by the Naturalis Biodiversity Center and sequences additionally obtained from GenBank, the Sponge Barcode Project and from Oliver Voigt (München) from the Red Sea, Indonesia, Australia, and a few sequences from other parts of the world, to demonstrate the affiliation of the compared species. Please note that Arturia sequences do not appear in the same clade, indicating Arturia is non-monophyletic. Numbers at the root of clades are bootstrap values of 1000 replicates. Since the high number of sequences were difficult to read in detail, we subdivided the present tree in three detailed sections 2A, 2B, and 2C.