Proceraea hanssoni, Nygren, Arne, 2004

Nygren, Arne, 2004, Revision of Autolytinae (Syllidae: Polychaeta)., Zootaxa 680, pp. 1-314 : 53-56

Proceraea hanssoni sp. n. (Fig. 13A–H)

Proceraea sp1 Nygren & Sundberg 2003: GenBank sequences, 16S rDNA partial sequence AF474275 , and 18S rDNA partial sequence AF474321 .

Material examined. USA: holotype ( SMNH 5949), and 31 spms (21 spms in formalin, 5 spms on slides (3 rear ends in author's collection for DNA analyses)), 5 spms in author's collection for DNA analyses, Washington, San Juan Island, 48°32.73'N 123°00.75'W, epifauna on floating dock outside Friday Harbor laboratory, sponges, hydroids, barnacles, Jan 2001; 2 paratypes ( SMNH 5950, 5951) (female and male epitokes), and additional 9 male epitokes and 4 female epitokes, Washington, San Juan Island, 48°32.73'N 123°00.75'W, collected with light on floating dock outside Friday Harbor laboratory, Jan 2001.

Diagnosis. Proceraea with black transverse intersegmental bands on every segment.

Description. Length 2.9–4.2 mm for first 13 chaetigers, including regenerating stolonial chaetigers 7–11 mm for 41–80 chaetigers, width 0.3–0.4 mm. Live specimens white with transverse intersegmental black bands on dorsal side (Fig. 13A); nuchal epualettes brownish; intestinal region yellowish­brownish; anterior appendages with red­brown tips; eyes dark red. Colour markings preserve well. Ciliation present on prostomium, nuchal epaulettes, and a few segments ventrally.

Eyes large, separated (Fig. 13B); eye spots absent. Palps in dorsal view projecting 1/4– 1/3 of prostomial length (Fig. 13B), fused. Extension of nuchal epaulettes to end of tentacular segment (Fig. 13B).

Median antenna reaching chaetiger 12–16 (n=9). Lateral antennae and dorsal tentacular cirri, length 1/3–1/2 of median antenna. Ventral tentacular cirri 1/3–2/3 as long as dorsal pair. First dorsal cirri as long as or 2/3 of median antenna, second dorsal cirri as long as or 2/3 of dorsal tentacular cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length, 2/3 of or equal to body width (Fig. 13A, B). Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded conical, small. Anterior 13 chaetigers with 3–5 aciculae, 1–2 in regenerating part. Chaetal fascicle with 10–15 compounds in anterior chaetigers, 3–7 in regenerating part. Compound chaetae with small distal tooth (Fig. 13F, G); serration present. Single thick bayonet chaetae (Fig. 13H), present in regenerating stolonial chaetigers.

Pharynx with sinuation anterior to proventricle. Trepan in chaetiger 1–2, with 18 unequal teeth (Fig. 13E); 9 large teeth and 9 smaller; 1 large alternating with 1 small, arranged in 2 rings. Basal ring present; infradental spines absent. Proventricle equal in length to 1–2 segments in chaetiger 6–10 with 35–41 rows of muscle cells (n=5). Anal cirri equal in length to body width.

Reproduction. Schizogamous reproduction by anterior scissiparity behind chaetiger 13. Stolon­forming specimens and swarming stolons common in January.

Morphology of epitokous stages.

Male. Length in preserved specimens 6–11.2 mm for 6+(26–34)+(35–68) chaetigers (n=10), width in region a 0.4–0.6 mm, width in region b 0.7–1.2 mm. Live specimens with black transverse intersegmental bands (Fig. 13C); body white in region a, dark brown in region b, more yellowish brown in region c; antennae, first dorsal cirri and nuchal epaulettes brown, dorsal cirri slightly brown; ventral side dark brown especially parapodial lobes in region b. Preserved specimens with black intersegmental bands, dorsal cirri pale brownish, ventral side brownish, especially in a midventral longitudinal line and in glandular portions of parapodial lobes. Ciliation absent, except for nuchal epaulettes.

Prostomium with concave anterior margin. Nuchal epaulettes triangular, reaching beginning of chaetiger 1.

Median antenna reaching middle of region b (chaetiger 20–25) in live specimens. Lateral bifid antennae (Fig. 13C), 3–4 times as long as prostomial width; basal part 1/3 of total length, outer ventral rami 1/2–3/ 4 in length of inner dorsal rami. Frontal processes, equal to 1/3 of prostomial width. Tentacular cirri 2 pairs, dorsal pair as long as 2–3 times prostomial width (Fig. 13C), ventral pair 1/ 3 in length of dorsal. First dorsal cirri, equal in length to median antenna; achaetous knobs present. Cirri in region a (Fig. 13C), equal to 1/ 2–3/4 of body width; cirri in region b and c successively shorter, in region b equal to 1/5– 1/4 of body width, in region c 1/4 of body width. Ceratophore on median antenna, small cirrophores on tentacular cirri, large cirrophores on first dorsal cirri, and cirrophores on cirri in region a, present; cirrophores otherwise absent. Cirri in region a slightly fusiform, other appendages cylindrical (Fig. 13C).

Region a and b with 2 neuropodial aciculae, 1–2 in region c; 2 anterodorsal, and 4 thick and 5 thin posteroventral notopodial aciculae in region b. Neuropodial chaetal fascicle with 7–12 compounds in region a and b, 4–6 in region c; single bayonet chaetae beginning at chaetiger 1. Notopodial chaetal fascicle with c. 25 swimming chaetae. Anal cirri equal in length to cirri in region c.

Female. Length in preserved specimens 9.6–15.2 mm for 6+(20–22)+(77–86) chaetigers (n=5), width in region a 0.4–0.7 mm, width in region b 1.0– 1.3 mm. Live specimens with black transverse intersegmental bands; body with scattered dark pigments especially on ventral side; body filled with either yellow or pinkish egg. Preserved specimens with black intersegmental bands, otherwise yellowish with scattered black pigments, more concentrated in glandular portions of parapodial lobes. Ciliation absent, except for nuchal epaulettes.

Prostomium with straight anterior margin. Nuchal epaulettes triangular, reaching end of chaetiger 1, winding back around bases of first dorsal cirri and dorsal tentacular cirri (Fig. 13D).

Median antenna reaching chaetiger 4. Lateral antennae, slightly shorter than median antenna. Tentacular cirri 2 pairs, dorsal pair 2/3–4/ 5 in length of lateral antennae, ventral pair 1/4–1/ 3 in length of dorsal. First dorsal cirri, equal in length to dorsal tentacular cirri; achaetous knobs present. Cirri in region a, equal to 1–1.5 times body width; cirri in region b longer than in a, equal to body width; cirri in region c successively shorter towards the end, c. 1/4 of body width. Small tentacular cirrophores, cirrophores on all dorsal cirri, except in posterior part of region c, present. Cirri in region a slightly fusiform, other appendages cylindrical (Fig. 13D).

Region a and b with 2 neuropodial aciculae, 1–2 in region c; 2 anterodorsal, and 3–4 thick and 4–5 thin posteroventral notopodial aciculae in region b. Neuropodial chaetal fascicle with 7–12 compounds in region a and b, 4–6 in region c; single bayonet chaetae beginning at chaetiger 1. Notopodial chaetal fascicle with c. 25 swimming chaetae. Anal cirri equal in length to posterior cirri in region c.

Habitat. Found almost exclusively in Halichondria sp., 1 m of depths.

Distribution. North East Pacific. Washington. Only known from type locality.

Etymology. Named in honour of Hans G. Hansson.

Remarks. This is an easily recognized species both alive and preserved, as the black transverse markings are retained. In the molecular analysis it is most closely related to P. prismatica . Other banded species include P. fasciata and P. m a d e i re n s i s nom. n., but P. f a s ­ ciata has broad red bands often at irregular intervals, and not on every segments; P. m a d e i ­ rensis has brown intrasegmental bands. Autolytus (Polybostrichus) triangulifer Grube, 1878 ( Procerini incertae sedis ), only known from male stolons, could also be a close relative, but in A. triangulifer the black colour markings are triangle shaped.

Proceraea longilappeta ( Imajima, 1966) comb. n. (Fig. 14A–E) Autolytus (Regulatus) misakiensis longilappetus Imajima, 1966: 63 –65, fig. 19A–F.

Material examined. Japan: 2 paratypes NSMT­Pol P­ 18, Onagawa, intertidal.

Diagnosis. Proceraea with nuchal epaulettes reaching end of chaetiger 1, and with large trepan teeth.

Description. Paratypes complete, length 7.4–13 mm for 64–103 chaetigers, width 0.4–0.5 mm. Preserved material yellowish without colour markings; eyes brownish red. Colour in live specimens orange ( Imajima 1966). Ciliation not possible to assess.

Eyes confluent, or almost confluent (Fig. 14A, B); eye spots absent. Palps in dorsal view projecting c. 1/4 of prostomial length (Fig. 14B), fused. Extension of nuchal epaulettes to end of chaetiger 1 (Fig. 14A), distinctly curved.

Median antenna reaching chaetiger 9–10. Lateral antennae and dorsal tentacular cirri, length 1/2 of median antenna. Ventral tentacular cirri 1/3 as long as dorsal pair. First dorsal cirri as long as median antenna, second dorsal cirri 2/3 as long as dorsal tentacular cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length, c. 1/3 of body width (Fig. 14A, B). Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded conical, small. Anterior chaetigers with 2–3 aciculae, 1–2 in median and posterior. Chaetal fascicle with 10–15 compounds in anterior chaetigers, 5–10 in median and posterior. Compound chaetae with small distal tooth (Fig.14D, E); serration present. Single thick bayonet chaetae, beginning at chaetiger 50.

Pharynx with sinuation anterior and lateral to anterior half of proventricle (Fig. 14B). Trepan in chaetiger 4, with 18 unequal teeth, 9 large and 9 smaller; 1 large alternating with 1 small, arranged in 2 rings; trepan teeth large (Fig. 14C). Basal ring present; infradental spines absent. Proventricle equal in length to 5–6 segments in chaetiger 6–12 (Fig. 14B) with 65–71 rows of muscle cells. Anal cirri equal in length to 1/4 of body width.

Reproduction. Unknown.

Habitat. Intertidal.

Distribution. North West Pacific. Northern Japan.

Remarks. Proceraea longilappeta was originally described as a subspecies of P. m i s ­ akiensis ( Imajima 1966), but the taxon has more in common with other Proceraea ­species than with P. misakiensis . See remarks for P. monoceros .