Philine mcleani Valdés, Cadien & Gosliner, 2016, sp. nov.

Philine mcleani sp. nov.

Figures 13–14

Type material. HOLOTYPE: Beaufort Sea, Arctic Ocean (70º35.1’N, 146º35.3’W), 48 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-459), 13 Aug 1972, 9 mm preserved length (LACM 3434).

Other material examined. Beaufort Sea, Arctic Ocean (71º41.5’N, 145º23.8’W), 79 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-456), 9 Aug 1972, 11 specimens 6–9 mm preserved length (LACM 72- 249.11). Beaufort Sea, Arctic Ocean (71º05.7’N, 148º41.0’W), 55 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-467), 19 Aug 1972, 13 specimens 7–9 mm preserved length (LACM 72-256.19). Beaufort Sea, Arctic Ocean (70º51.5’N, 145º17’W), 348 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-457), 9 Aug 1972, 1 specimen 8 mm preserved length (LACM 72-250.11). Beaufort Sea, Arctic Ocean (70º49.0’N, 143º45.0’W), 575 m depth, R/ V Ocean Sentinel (Oregon State University OTB-715), 7 Aug 1978, 1 specimen, 14 mm preserved length (LACM 1978-249.1). Beaufort Sea, Arctic Ocean (70º34.80’N, 144º23.10’W), 71 m depth, R/ V Glacier (Oregon State University OTB-450), 7 Aug 1972,> 20 specimens 6–19 mm preserved length + 1 broken shell (LACM 1972-243.13). Beaufort Sea, Arctic Ocean (70º10.30’N, 144º33.50’W), 27 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-453), 8 Aug 1972, 4 specimens 10–12 mm preserved length + 1 broken shell (LACM 72-246.23). Beaufort Sea, Arctic Ocean (70º31.75’N, 147º33.5’W), 20 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-463), 15 Aug 1972, 2 specimens 8–11 mm preserved length (LACM 72- 254.15). Northeast of Prudhoe Bay, Beaufort Sea, Arctic Ocean (70º26’N, 147º26.10’W), 16 m depth, R/ V Alumiak (Oregon State University SMG-1443, SMG-1445, SMG-1446), 28 Aug 1976, 2 shells, 1.5–2.1 mm long (LACM 1976-669.1). Beaufort Sea, Arctic Ocean (70º20’N, 144º40’W), 41 m depth, R/ V Glacier (WBS-72) (Oregon State University OTB-452), 7 Aug 1972, 12 specimens 6–9 mm preserved length (LACM 72-245.9). Northeast of Baxter Island, Beaufort Sea, Arctic Ocean (70º10.40’N, 143º33.40’W), 20 m depth, R/ V Alumiak (Oregon State University SMG-1461, SMG-1464), 31 Aug 1976, 2 shells, 1.8–4.1 mm long (LACM 1976-670.1).

Description. Live animals unknown. Preserved specimens to 9 mm long. Body oval, about twice as long as wide (Fig. 13 A). Cephalic shield short, wide, rounded posteriorly. Parapodia short and thick. Shell internal, occupying the entire posterior shield. Shell to 6.2 mm long, bulloid elongate (Fig. 13 B–C). Shell aperture broad, wider near the anterior end. Apex with a flat spire. Lip rising slightly above apex. Sculpture composed of fine spiral lines, formed by fused punctuations (Fig. 13 D).

Digestive system with a large, oval buccal bulb, surrounded by the central nervous system centrally (Fig. 14 A). Esophagus and salivary glands not observed. Gizzard large, muscular. Gizzard plates (3) large, oval, wider and thicker centrally, with indented ends (Fig. 13 E–F). Radular formula 17 x 1.0.1. Lateral teeth with large bases and robust, hook-shaped cusps bearing numerous denticles (Fig. 13 G).

Reproductive system with a long and convoluted prostate connected directly into the penis, lacking a tubular loop. Penis complex with a large basal projection and a hammer-head apex (Fig. 13 H, 14C). Penis with a strong retractor muscle attached to the base.

Range. Beaufort Sea (Fig. 3 C), 16–575 m depth.

Etymology. Dedicated to James H. McLean to honor his lifetime contribution to malacology and recognize his unpublished work on Philine, which constituted the foundation of this paper.

Remarks. Philine mcleani sp. nov. is clearly distinct from other species of Philine from the area of study, it has a wider shell and characteristic gizzard plates notched on both ends. This species is similar to Philine finmarchica M. Sars, 1859 from the North Atlantic and Arctic Oceans. These two species share a similar shell and radular morphology as well as a nearly identical penis (see Ohnheiser & Malaquias, 2013; Chaban & Soldatenko, 2009). Differences include the shape of the gizzard plates, which are slightly notched on both ends in Philine mcleani sp. nov., and the apical shell morphology, with a more distinct wing in P. finmarchica.

Another similar species is Globophiline kawamurai Habe, 1958 described from Chiba, Japan, which also has a globose shell with a n x 1.0.1 radular formula and three elongate gizzard plates, but the shell is more oval and less quadrangular than in P. mcleani sp. nov.

Chaban & Soldatenko (2009) erected the genus Praephiline for P. finmarchica (type species) as well as P. thurmanni Er. Marcus & Ev. Marcus, 1969 and P. chilla Er. Marcus & Ev. Marcus, 1969. Should molecular data support these species form a clade distinct from Philine sensu stricto, P. mcleani is likely to also belong there. The hammer-head shaped penis with warts seems to be a synapomorphy for this group.