Proximal, Korshunova & Fletcher & Martynov, 2025

Coryphellina O’Donoghue, 1929 View in CoL ( Figs 1, 2, 5C, 12)

= Nossis Bergh, 1902 View in CoL .

O’Donoghue 1929: 797–802.

Type species: Coryphellina rubrolineata O’Donoghue, 1929 .

Diagnosis: Body narrow. Notal edge present, reduced, discontinuous, in several indistinct pieces. Cerata on low elevations, in several groups. Rhinophores similar in length or shorter than oral tentacles, densely papillate. Anterior foot corners present. Anus pleuroproctic. Elaborate oral glands present. Central teeth with narrow compressed cusp and distinct denticles. Lateral teeth denticulated with attenuated process basally. Proximal receptaculum seminis usually bilobed.Distal receptaculum seminis present.Short prostatic, not granulated vas deferens. Penis conical to bulbous.

Species included: Coryphellina albomarginata ( Miller, 1971) , Coryphellina arveloi (Ortea and Espinosa, 1998) , Coryphellina aurora Ekimova et al., 2022 , Coryphellina (?) delicata (Gosliner and Willan, 1991), Coryphellina exoptata (Gosliner and Willan, 1991) , Coryphellinaflamma Ekimova etal.,2022, Coryphellina (?) hamanni (Gosliner, 1994) , Coryphellina indica (Bergh, 1902) , Coryphellina lotos Korshunova et al., 2017 , Coryphellina marcusorum (Gosliner and Kuzirian, 1990) , Coryphellina pannae Ekimova et al., 2022 , Coryphellina (?) poenicia (Burn, 1957), Coryphellina pseudolotos Ekimova et al., 2022 , Coryphellina rubrolineata O’Donoghue, 1929 , and Coryphellina (?) westralis (Burn, 1964).

Coryphellina iurmanovi sp.nov. ( Fig. 5C, 12) urn:lsid:zoobank.org:act:

Holotype: ZMMU Op-132.1, L = 9 mm (preserved), Vietnam, Nhatrang Bay , 10–15 m, 08.10.2007, coll O. V. Savinkin.

Paratype: ZMMU Op-132.2, L = 15 mm (preserved), Vietnam, Nhatrang Bay , 10–15 m, 08.10.2007, coll O . V. Savinkin .

Etymology: In honour of Anton Iurmanov ( Moscow, Institute of Plant Physiology RAS) who greatly helped with the organization of Kurile expeditions.

Description

External morphology ( Fig. 12A, G–I) Body relatively narrow. Foot and tail narrow, anterior foot corners long. Rhinophores c. 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 cnidosacs. Distinct notal edge remains mostly below cerata clusters. Digestive gland diverticulum fills significant volume of the cerata. Anal opening pleuroproctic on right side. Reproductive openings lateral, below first anterior cluster of cerata.

Colour ( Fig. 12G, H) Background colour opaque whitish-greyish to yellowish, with orange patches between clusters of cerata. Digestiveglanddiverticulalightreddish-orange.Rhinophorebackground colour similar to body, with reddish patches.Oral tentacles similar to body, with whitish spots, and lilac encrustations. Lilac pigment also occurs on anterior foot corners. Subapical parts of cerata and rhinophores with darker reddish-orange distinct to indistinct rings. Apical parts of cerata without opaque cap of white. A thin lilac line runs through the middle part of almost the whole dorsal side, similar lines run along reduced notal edge on both sides, and at the tail all three lines almost meet together.

Jaws ( Fig. 12B, C) Edge of masticatory processes bears up to ca. 30 sharp denticles that continue to form two or more rows of denticles on the body of the masticatory processes.

Radula ( Fig. 12D, E) Radula formula 29 × 1.1.1. Central tooth elongate-triangular with short narrow, compressed cusp. Central tooth bears up to at least c. 10 well-defined, separated, long lateral denticles strongly adpressed toward cusp. Cusp is strongly compressed by adjacent first lateral denticles. Lateral teeth broadly triangular with outer process obtuse and very attenuated posteriorly bearing up to at least c. 17 sharp denticles.

Reproductive system ( Fig. 12J) Hermaphroditic duct leads to voluminous ampulla. Vas deferens is short, prostatic. Penial sheath is large, wide. Penis is conical. Oviduct connects through insemination duct into female gland complex. Vagina short and indistinct. Proximal receptaculum seminis large, oval to pear-shaped, bilobed, comprised of two distinct reservoirs. Distal receptaculum seminis small.

Ecology: Shallow water species, stony and rocky habitats.

Distribution: Vietnam, possibly more broadly distributed in some parts of the Indo-West Pacific.

Remarks: All Coryphellina species constitute a highly-supported clade (PP = 1, BS = 100; Fig. 5C). Two Coryphellina iurmanovi sp. nov. formed a distinct, separate highly supported clade (PP = 1, BS = 100), and had the closest position to the clades C. lotos and C. pseudolotos with high support (PP = 1, BS = 100; Fig. 5C). Uncorrected COI p -distances within the C. iurmanovi sp. nov. clade are 1.3%.The COI minimal uncorrected p -distances between the C. iurmanovi sp. nov. clade and clade C. rubrolineata are 13.0%; clade C. arveloi are 14.5%; clade C. aurora are 12.0%; clade C. lotos are 8.6%; clade C. exoptata are 14.5%; clade C. pseudolotos are 9.9%; clade C. pannae are 12.6%; and clade C. flamma are 12.4%. The described herein species was identified as Coryphellina ‘ rubrolineata ’ in Korshunova et al. (2017a). Morphologically Coryphellina iurmanovi sp. nov. differs from all species (including the type species C. rubrolineata that possesses an almost continuous purple line through the middle of its back and lateral sides) by the details of its coloration. Interestingly, according to the molecular phylogenetic analysis, Coryphellina iurmanovi sp. nov. ( Fig. 5C, 12) is related to the taxa with an absence of, or indistinct, purple lines, such Coryphellina lotos ( Korshunova et al. 2017a) , but distantly related to the canonical type species with mostly continuous purple lines, Coryphellina rubrolineata ( Fig. 5C).