Coryphellina lotos, Korshunova, Tatiana, Martynov, Alexander, Bakken, Torkild, Evertsen, Jussi, Fletcher, Karin, Mudianta, I Wayan, Saito, Hiroshi, Lundin, Kennet, Michael Schroedl, & Picton, Bernard, 2017

Korshunova, Tatiana, Martynov, Alexander, Bakken, Torkild, Evertsen, Jussi, Fletcher, Karin, Mudianta, I Wayan, Saito, Hiroshi, Lundin, Kennet, Michael Schroedl, & Picton, Bernard, 2017, Polyphyly of the traditional family Flabellinidae affects a major group of Nudibranchia: aeolidacean taxonomic reassessment with descriptions of several new families, genera, and species (Mollusca, Gastropoda), ZooKeys 717, pp. 1-139 : 44-46

Coryphellina lotos sp. n. Fig. 38

Type material.

Holotype. ZMMU Op-515, 15.5 mm long (live), Japan, Pacific coast of Honshu, Osezaki, 10-15 m depth, 10.09.2016, coll. T.A. Korshunova, A.V. Mar tynov. 2 paratypes, ZMMU Op-516, up to 17 mm long (live), same locality and dates as holotype.

Type locality.

Osezaki, Pacific coast of Honshu, Japan.

Diagnosis.

Considerably reduced notal edge, forming several clusters, background colour light violet, digestive gland in cerata light brownish, subapical parts of cerata reddish lilac, apical parts of cerata without white pigment, rachidian tooth with up to seven distinct denticles, adpressed to rachidian cusp, lateral teeth with up to nine denticles, penis conical.

Etymology.

After the lotus flower in reference to the similarity of the colour of the new species to the common colour of the lotus flower.

Description.

External morphology (Fig. 38 A–E). Body relatively narrow. Foot and tail narrow, anterior foot corners long. Rhinophores ca. 1.5 times shorter than oral tentacles, strongly papillate. Dorsal cerata finger-shaped to fusiform, forming several slightly elevated clusters along dorsal edges. Apices of cerata gradually pointed, with elongate cnidosac. Distinct notal edge remains mostly below cerata clusters. Digestive gland diverticulum fills significant volume of the cerata. Anal opening pleuroproctic on right side below second large ceratal clusters. Reproductive openings lateral, below first anterior cluster of cerata.

Colour (Fig. 38A). Background colour light violet. Digestive gland diverticula light brownish. Rhinophore background colour similar to body. Oral tentacles lilac (except for translucent tips). Subapical parts of cerata and rhinophores brighter reddish lilac. Apical parts of cerata without opaque cap of white pigment.

Jaws (Fig. 38G, H). Masticatory process more than one-third as long as jaw body. Edge of masticatory processes bears ca. 35 sharp denticles that continue to form at least two rows of denticles on body of masticatory processes.

Radula (Fig. 38I). Radula formula: 26 × 1.1.1 (31 mm). Rachidian tooth elongate-triangular with short narrow cusp of less than 1/3 of the tooth length (Fig. 38I). Rachidian tooth bears between four and seven well-defined separated long lateral denticles strongly adpressed towards cusp. Cusp is compressed by adjacent first lateral denticles. Lateral teeth (Fig. 38I) broadly triangular with obtuse and very attenuated posteriorly outer process, bear seven to nine sharp denticles.

Reproductive system (Fig. 38J). Diaulic. Hermaphroditic duct leads to convoluted ampulla of about two whorls. Vas deferens is relatively long, no distinct prostate. Penial sheath is large, wide. Penis is conical. Oviduct connects through insemination duct into female gland complex. Vagina short and indistinct. Receptaculum seminis large, oval, bilobed. Distal receptaculum seminis present, small.

Ecology.

Shallow water species, stony and rocky habitats.

Distribution.

Pacific side of middle Japan (Honshu).

Remarks.

The three specimens of Coryphellina lotos sp. n. demonstrate uniformity in the body shape and colour and are readily distinguished from any previously described Coryphellina species, including C. rubrolineata , which is sister to C. lotos sp. n. according to the molecular phylogenetic analysis (Fig. 1).