Reproductive system of <i>Tergiposacca longicerata</i> sp. nov. (CASIZ 103768).

<p>Abbreviations: al, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; od, oviduct; p, penis; pr, prostate; rs, receptaculum seminis; vd, vas deferens.</p

Scanning electron micrographs of the radula, jaws and masticatory edge of <i>Tergiposacca longicerata</i> sp. nov. (CASIZ 203083).

<p>(A) Jaws of the specimen. (B) Detailed view of the masticatory border. (C-D) Radular teeth.</p

Photographs of the types species of the traditional genera of Fionidae recovered in this study (excluding <i>Cuthonella</i> and <i>Murmania</i>).

<p>(A) <i>Tenellia adspersa</i>, photograph by Terrence M. Gosliner. (B) <i>Tergipes tergipes</i>, photograph by Terrence M. Gosliner. (C) <i>Fiona pinnata</i>, photograph by Terrence M. Gosliner. (D) <i>Cuthona nana</i>, photograph by Terrence M. Gosliner. (E) <i>Calma glaucoides</i>, photograph by Fredrik Pleijel. (F) <i>Eubranchus tricolor</i>, photograph by Terrence M. Gosliner.</p

Phylogenetic hypothesis based on the combined dataset (H3+COI+16S) inferred by Bayesian analysis (BI).

<p>Support values shown represent posterior probabilities from Bayesian inference and bootstrap values from Maximum likelihood (PP/ML). **Referred to as <i>Cuthona</i> sp. 13 in Pittman and Fiene [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167800#pone.0167800.ref049" target="_blank">49</a>].</p

Photographs of the types species of the new genera of Fionidae.

<p>(A) <i>Abronica abronia</i>, photograph by Terrence M. Gosliner. (B) <i>Tergiposacca longicerata</i> photograph by Terrence M. Gosliner. (C) <i>Rubramoena amoena</i> photograph by Bernard Picton.</p

Accepted genera of Tergipedidae based on bibliography.

<p>Accepted genera of Tergipedidae based on bibliography.</p

Minimum COI gene pairwise uncorrected <i>p</i>-distances amongst Fionidae genera.

<p>Minimum COI gene pairwise uncorrected <i>p</i>-distances amongst Fionidae genera.</p

Different morphotypes of <i>Tergiposacca longicerata</i> sp. nov.

<p>(A) Specimen from Tingloy, the Philippines (CASIZ 177605). (B) Specimen from Puerto Galera, Philippines (CASIZ 208490). (C) Specimen from Tingloy, the Philippines (CASIZ 186236). All the photographs by Terrence M. Gosliner.</p

Minimum COI gene pairwise uncorrected <i>p</i>-distances amongst key species with names after analyses.

<p>Minimum COI gene pairwise uncorrected <i>p</i>-distances amongst key species with names after analyses.</p

A Radical Solution: The Phylogeny of the Nudibranch Family Fionidae

<div><p>Tergipedidae represents a diverse and successful group of aeolid nudibranchs, with approximately 200 species distributed throughout most marine ecosystems and spanning all biogeographical regions of the oceans. However, the systematics of this family remains poorly understood since no modern phylogenetic study has been undertaken to support any of the proposed classifications. The present study is the first molecular phylogeny of Tergipedidae based on partial sequences of two mitochondrial (COI and 16S) genes and one nuclear gene (H3). Maximum likelihood, maximum parsimony and Bayesian analysis were conducted in order to elucidate the systematics of this family. Our results do not recover the traditional Tergipedidae as monophyletic, since it belongs to a larger clade that includes the families Eubranchidae, Fionidae and Calmidae. This newly recovered clade is here referred to as Fionidae, the oldest name for this taxon. In addition, the present molecular phylogeny does not recover the traditional systematic relationships at a generic level, and therefore, systematic changes are required. We recognize the following clades within Fionidae: <i>Calma</i>, <i>Cuthona</i>, <i>Cuthonella</i>, <i>Eubranchus</i>, <i>Fiona</i>, <i>Murmania</i>, <i>Tenellia</i>, <i>Tergipes</i>, <i>Tergiposacca</i> gen. nov., <i>Rubramoena</i> gen. nov. and <i>Abronica</i> gen. nov. The type species of <i>Tergiposacca</i>, <i>T</i>. <i>longicerata</i> nov. sp. is described. The other two new genera have a previously described species as their type species. Most of these taxa, with the exceptions of <i>Eubranchus</i>, <i>Tergipes</i> and <i>Fiona</i> are composed of radically different constituent species from their traditional membership, but appear to be supported by morphological synapomorphies as well as molecular data. <i>Aenigmastyletus</i>, <i>Catriona</i>, <i>Phestilla</i>, <i>Tenellia</i> and <i>Trinchesia</i> are nested within other clades and, thus are here considered as synonyms of the larger clades. The phylogenetic position and validity of <i>Myja</i>, <i>Guyvalvoria</i>, <i>Leostyletus</i> and <i>Subcuthona</i> still need to be tested in future studies when material becomes available.</p></div