Philine bakeri Dall 1919

Philine bakeri Dall, 1919

Figure 9

Philine bakeri Dall 1919: 300.

Type material. Holotype (USNM 225194): South Coronado Island, Baja California, Mexico (Fig. 9 D).

Other material examined. NORTHERN CALIFORNIA: Off Hopkins Marine Station, Pacific Grove, California (36º37.5’N, 121º54’W), 36 m depth, 1960–64, 1 shell, 2 mm long, leg. McLean (LACM 60-23.40).

SOUTHERN CALIFORNIA: About half mile west of Yellowbanks, South side of Santa Cruz Island, California (33º59’N, 119º38’W), 15–18 m depth, 23 Aug 1969, 1 shell, 1.6 mm long, leg. McLean (LACM 69- 32.40). Gull Island, off the south side of Santa Cruz Island, California (33º57.2’N, 119º49.6’W), 10–12 m depth, 24 Jun 1973, 1 shell, 1.3 mm long, leg. McLean (LACM 73-11.39). Crescent Bay, Laguna Beach, California (33º32.8’N, 117º48.0’W), 9 m depth, Jul 1974, 1 shell, 1.2 mm long, Leg. Bemis (LACM 74-80.13). Pier at Marine Lab, Fisherman Cove, Santa Catalina Island, California (33º26.7’N, 118º29.0’W), 3–5 m depth, 12 Oct 1977, 8 shells, 1.1–1.6 mm long, leg. LaFollette (LACM 77-110.9). Isthmus Cove, Santa Catalina Island, California (33º26.5’N, 118º29’W), 9–30 m depth, Jun–Jul 1971, 1 shell, 2.3 mm long, leg. McLean (LACM 71-99.58). La Jolla kelp beds, California (32º50’N, 117º18’W), 12 m depth, 9 Sep 1972, 2 shells, 1.5–1.9 mm long, leg. McLean, Margetts, Savino (LACM 72-110.31).

BAJA CALIFORNIA: Punta Final, 10 miles south of Bahía San Luis Gonzaga, Baja California, Mexico (29º48’N, 114º17’W), 36 m depth, 1 Jan 1961, 1 shell, 1.7 mm long, leg. Campbell, Shasky, Sphon (LACM 61- 1.12). Northeast of Isla Cedros, Baja California, Mexico (28º22’N, 115º11.5’W), 10 m depth, 24 Sep 1972, 1 shell, 1.8 mm long, leg. McLean (LACM 72-113.28). Northeast of Isla Cedros, Baja California, Mexico (28º20.41’N, 115º11.33’W), 18–30 m depth, 18–19 Oct 1971, 1 shell, 2.6 mm long, leg. McLean, LaFollete, Swift (LACM 71- 152.34). Off Cedros Village, east side of Isla Cedros, Baja California, Mexico (28º00.91’N, 115º08.75’W), 56–76 m depth, R/ V Searcher (248) 20 Oct 1971, 1 shell, 2 mm long, leg. McLean & LaFollette (LACM 71-157.9). Southwest side of Natividad Island, Baja California, Mexico (27º53.3’N, 115º12.7’W), 18–24 m depth, 25 Sep 1972, 1 shell, 2.1 mm long, leg. McLean (LACM 72-117.35). Punta Rompiente, Baja California, Mexico (27º43.25’N, 115º00.50’W), 15 m depth, R/ V Searcher (253), 21 Oct 1971, 1 shell with dried soft parts, 1.7 mm long, leg. McLean & LaFollette (LACM 71-161.42). Punta San Pablo, Baja California, Mexico (27º12.91’N, 114º27.50’W), 21–24 m depth, R/ V Searcher (281), 24 Oct 1971, 1 shell, fragmented, leg. Swift & Huddleston (LACM 71-177.32). Punta San Pablo, Baja California, Mexico (27º12.50’N, 114º28.83’W), 21–30 m depth, R/ V Searcher (282), 25 Oct 1971, 1 shell, 1.9 mm long, leg. McLean & LaFollette (LACM 71-178.52). Punta Pequeña, San Juanico Bay, Baja California, Mexico (26º15.00’N, 112º27.33’W), 9 m depth, 27 Oct 1971, 1 shell, 2 mm long, leg. McLean (LACM 71-180.22).

Description. Live and preserved animals unknown. Shell to 2 mm long, small, elongate, narrower posteriorly (at apex) than anteriorly (Fig. 9 A–F). Apex flat, with no spire. Lip edge straight, crenulate, in apertural view. Sculpture of conspicuous punctate striae.

Radular formula 13–14 x 2.1.0.1.2. Lateral teeth broad, with strong denticles (Fig. 9 G). Outer teeth hook-shaped. Gizzard plates absent. Reproductive system unknown.

Range. Pacific Grove, California to San Juanico Bay, Baja California (Fig. 3 A). Depth range 3– 76 m.

Remarks. Very little is known about this relatively common species in Southern California. All specimens here studied consisted of empty shells or dried specimens in which anatomical details could not be examined. The presence of a callus deposition on the inner whorl near the spire of 2 mm shells indicates that these specimens are mature.

Abbott (1974) stated that the shell of this species is buried in a body of 35 mm length, but gave no source; this claim is most likely a mistaken reference to Philinorbis albus, the only native species in southern California have such a large body size.

Gosliner (1996) correctly distinguished Philine bakeri from Philinorbis albus (as Philine alba), but also suggested that P. bakeri, Philine polystrigma (which he redescribed) and Laona californica (as Philine californica) are similar and require further study. However, L. californica, is easily distinguishable by having a unique net-like sculpture and P. polystrigma has a more globose shell.

Philine bakeri is similar to the European Philine scabra (O. F. Müller, 1784), type species of Hermania (Ohnheiser & Malaquias 2013). Further examination of specimens may provide additional similarities (i.e., gizzard plates and reproductive system) between these two species. Chaban et al. (2015) provided morphological support for the validity of Hermania as distinct from Philine sensu stricto, and Oskars et al. (2015: supplementary figure S2) produced a molecular phylogenetic tree in which P. scabra and P. indistincta are sister to species of Philine sensu stricto. However this relationship has low support values. If this is confirmed with supported phylogenetic evidence, and Hermania removed from the synonymy of Philine, P. bakeri is very likely to belong there.