Pterocirrus burtoni, Pleijel, Fredrik, Aguado, Maria Teresa & Rouse, Greg W., 2012

Pleijel, Fredrik, Aguado, Maria Teresa & Rouse, Greg W., 2012, New and lesser known species of Chrysopetalidae, Phyllodocidae and Syllidae from south California (Phyllodocida, Aciculata, Annelida), Zootaxa 3506, pp. 1-25 : 12-14

Pterocirrus burtoni , new species

Figs 9 , 10

Type material: Holotype SIO-BIC A2615, paratypes SIO-BIC A2616, SIO-BIC A2617, SIO-BIC A2618, SIO-BIC A2619, SIO-BIC A2620, SIO-BIC A2621, SIO-BIC A2622, SIO-BIC A2623, SIO-BIC A2624, SIO-BIC A2625, SIO-BIC A2626, SIO-BIC A2627, SIO-BIC A2628, SIO-BIC A2629, SIO-BIC A2630.

Material examined: California. Holotype, anterior end preserved in formaldehyde (SIO-BIC A2615), La Jolla, pilons of Scripps Pier, 32°52.024’N, 117°15.437’W, intertidally, colls FP & GWR 20 Aug 2007; 1 paratype, anterior end preserved in formaldehyde (SIO-BIC A2616), posterior end in ethanol (SIO-BIC A2617), same collection data; 1 paratype, preserved in formaldehyde (SIO-BIC A2618), same collection data; 1 paratype, anterior end preserved in formaldehyde (SIO-BIC A2619), posterior in ethanol (SIO-BIC A2620), La Jolla, off La Jolla Cove, 32°51.211’N, 117°16.273’W, 19 m depth, Macrocystis pyrifera holdfasts, SCUBA, colls FP and GWR 23 Aug 2007; 1 paratype preserved in formaldehyde (SIO-BIC A2621), same collection data; 2 paratypes preserved in formaldehyde (SIO-BIC A2622), La Jolla, off La Jolla Cove, 32°50.713’N, 117°17.058’W, 12 m, colls FP and GWR 29 Aug 2007; 1 paratype, mature male, anterior end preserved in formaldehyde (SIO-BIC A2623), posterior in ethanol (SIO-BIC A2624), same collection data; 1 paratype, mature female, anterior end preserved in formaldehyde (SIO-BIC A2625), posterior end in ethanol (SIO-BIC A2626), same collection data; 1 paratype, mature female, preserved in formaldehyde (SIO-BIC A2627), same collection data; 1 paratype preserved in formaldehyde (SIO-BIC A2628), same collection data; 2 paratypes, preserved in formaldehyde (SIO-BIC A2629), La Jolla, off Casa Cove, 32°48.531’N, 117°17.239’W, 18 m depth, Macrocystis pyrifera holdfasts, SCUBA, coll. Eddie Kisfaludy 2 Feb 2010; 1 paratype, preserved in ethanol (SIO-BIC A2630), La Jolla, off Casa Cove, 32°51.058’N, 117°16.802’W, 17 m depth, Macrocystis pyrifera holdfasts, SCUBA, coll. Eddie Kisfaludy 11 Feb 2010; 1 paratype, preserved in ethanol, La Jolla, off Windansea, 32°50.26’N, 117°17.11’W, holdfasts of Macrocystis pyrifera , 15 m depth, colls GWR & Phil Zerofski 15 Oct 2010, destroyed for DNA sequencing.

Description: Entire specimen 24 mm long for 88 segments (paratype SIO-BIC A A2629). Live specimens yellowish white with brown pigmentation dorsally on small visible portion of segment 1 and on segment 2 and 3, absent on segment 4 and 5, and present on all following segments as transverse, midsegmental band ( Fig. 9 A, B). Venter unpigmented. Eyes dark red. Brown pigmentation retained in preserved specimens. Body slender, elongated cylindrical with truncate anterior and tapering posterior end, venter flattened. Prostomium rounded, about as long as wide ( Fig. 9 B). Palps and paired antennae tapering to fine tips, insert point without prostomial protuberance. Median antenna inserted near anterior border of prostomium, similar in shape and size to paired antennae and palps. Eyes large, rounded ( Fig. 9 B). Posterior part of prostomium incised with triangular part of segment 1 visible. Nuchal organs not observed. Everted proboscis densely covered with diffusely distributed filiform papillae, terminal ring with about 25 papillae. Cirri of segment 1 reaching segment 5–6, dorsal cirri of segment 2 and 3 reaching about segment 12, ventral cirri of segment 2 reaching about segment 6–7, with large foliaceous ventral extension ( Fig. 10 A). Segment 3 without neuropodial lobes and chaetae, segment 4 with neuropodial lobes and chaetae. Dorsal cirri almost twice as long as wide, asymmetrical at bases around longitudinal axis, with pointed tips ( Fig. 10 B). Supraacicular parapodial lobes distinctly larger and more elongated than subacicular lobes ( Fig. 10 C). Chaetae ca. 25. Rostrum of chaetal shaft with small teeth, similar to other Pterocirrus ( Eibye-Jacobsen 1991b, fig. 3H) and many other phyllodocids. Ventral cirri oval, near twice as long as wide, with poorly defined tips. Pygidial cirri long, cylindrical, evenly tapering with long pointed ends ( Fig. 9 A). Pygidial papilla absent. Several mature females with emerald green eggs collected in August, size ca. 100µm.

Etymology: Named in honor of Ron Burton, Marine Biology Research Division, Scripps Institution of Oceanography, for his interest in invertebrates.

Habitat: Only known from holdfasts of Macrocystis pyrifera and scrapings from the pilons of Scripps Pier in La Jolla.

Remarks: Pterocirrus burtoni n. sp., is a member of Pterocirrus as evidenced by the lack of a prostomial protuberance, the presence of a proboscis covered with long, filiform papillae, and an enlarged ventral wing on the ventral cirri of segment 2 ( Pleijel 1991). Pleijel in that study listed 11 species and subspecies of Pterocirrus worldwide, although for three of these ( Pterocirrus brevicornis Ehlers, 1905 , Pterocirrus ceylonicus Michaelsen, 1892 and Pterocirrus imajimai Ushakov, 1972 ) the generic affinity was considered uncertain and two ( Pterocirrus marginata Claparède, 1868 and Pterocirrus velifer ajacis Giard, 1913 ) were treated as nomina dubia. Pterocirrus slastnikovi Annenkova, 1946 and P. imajimai Uschakov, 1972 are deep-water species that lack eyes, and P. hunteri (Benham, 1921) and P. nidarosiensis Pleijel, 1987 have much wider dorsal cirri. Based on parapodial morphology it is close to P. macroceros and P. montereyensis , but is distinguished from these and other members of Pterocirrus by the unique pigmentation pattern, consisting of brown transverse bands which are absent on segment 4 and 5. The sequence for COI for Pterocirrus burtoni n. sp. (GenBank accession number JQ623497 ) showed a closest BLAST match to the phyllodocid Notophyllum crypticum ( GQ464333 , GQ464334 , GQ464341 ), with a maximum identity of 85%. The uncorrected pairwise distances from other known Pterocirris sequences; Pterocirrus montereyensis ( Hartman, 1936) (see below) and P. macroceros (GenBank AY996111 ) were 15%–17%.

Figures

FIGURE 9. Micrographs of live, relaxed specimen of Pterocirrus burtoni, new species (paratype SIO-BIC A 2629). A, entire specimen, dorsal view. B, anterior end, dorsal view. Scale bars A 250 µm, B 100 µm.

FIGURE 10. LM micrographs of Pterocirrus burtoni (SIO-BIC A 2625). A, ventral cirrus segment 2. Scale bar A 200 µm. B, dorsal cirrus median segment. Same scale. C, parapodial lobe and ventral cirrus, median segment. Same scale.