Proceraea scapularis ( Claparède, 1864 ), Claparede, 1864

Nygren, Arne, 2004, Revision of Autolytinae (Syllidae: Polychaeta)., Zootaxa 680, pp. 1-314 : 75-78

Proceraea scapularis ( Claparède, 1864) (Fig. 28A–E)

Autolytus (Stephanosyllis) scapularis Claparède, 1864: 567 –569, pl. 7, fig. 5. Autolytus megodon Saint­Joseph, 1887: 240 –241, pl. 11, fig. 111–113; Fauvel 1923: 317, fig. 122B–D.

Proceraea scapularis Okada 1933a: 647 –653, fig. 6B; Nygren & Sundberg 2003: GenBank sequences, 16S rDNA partial sequence AF474270 , and 18S rDNA partial sequence AF474316 .

Material examined. France: holotype of Autolytus megodon MNHN 920, Dinard, 13 Jul 1877; 1 spm in formalin (rear end in author's collection for DNA analyses), Banyuls­sur­ Mer, 42°28.9'N 03° 08.2E, dive, 10 m, sponges, hydroids, May 1997; 2 spms (1 spm on slide (rear end in author's collection for DNA analyses), 1 spm in author's collection for DNA analyses, Banyuls­sur­Mer, 42°29.6'N 03°10.2'E, epibenthic sledge, 59–62 m, tunicates and shells with epifauna, 26 Apr 2001.

Diagnosis. Proceraea with nuchal epaulettes reaching end of chaetiger 1; dorsum yellow with 2 black longitudinal lines at each side.

Description. Length 7.5–21.2 mm for 36–50 chaetigers, width 0.5 mm. Live specimens with 2 longitudinal black lines at each side of a yellow dorsum (Fig. 28A); nuchal epualettes brown; antennae, dorsal tentacular cirri, and first dorsal cirri brown; eyes red. Ciliation present on prostomium, nuchal epaulettes, and a few segments ventrally.

Eyes confluent (Fig. 28B); eye spots absent. Palps in dorsal view projecting c. 1/4 of prostomial length (Fig. 28B), fused. Extension of nuchal epaulettes to end of chaetiger 1 (Fig. 28B).

Median antenna reaching chaetiger 13–16 (n=2). Lateral antennae and dorsal tentacular cirri, length c. 1/2 of median antenna. Ventral tentacular cirri c. 1/3 as long as dorsal pair. First dorsal cirri c. 4/5 as long as median antenna, second dorsal cirri as long as ventral tentacular cirri. From chaetiger 1–27 cirri with usual alternation in direction, followed by 2 DDUU­groups (n=1). Dorsal cirri from chaetiger 3, of equal length, c. 1/3 of body width. Cirrophores present on tentacular segment and first dorsal cirri; cirrophores otherwise absent. All appendages cylindrical (Fig. 28A, B).

Parapodial lobes rounded conical, small. Anterior chaetigers with 2–3 aciculae, 1–2 in median and posterior. Chaetal fascicle with 12–20 compounds in anterior chaetigers, 3–10 in median and posterior. Compound chaetae with small distal tooth in anterior 10–20 chaetigers (Fig. 28D), more posterior with large distal tooth (Fig. 28E), still somewhat smaller than subdistal tooth; serration present. Single thick bayonet chaetae beginning between chaetiger 25–30.

Pharynx with sinuation anterior and lateral to anterior half of proventricle (Fig. 28A). Trepan in chaetiger 2–3 (Fig. 28B), with 18 unequal teeth, 9 large and 9 smaller; 1 large alternating with 1 small (Fig. 28C), arranged in 2 rings. Basal ring present; infradental spines absent (Fig. 28C). Proventricle equal in length to 3–4 segments in chaetiger 6–9 (Fig. 28A) with 45–50 muscle cells (n=3). Anal cirri equal in length to c. 1/3 of body width.

Reproduction and morphology of epitokous stages. Schizogamous reproduction by anterior scissiparity from behind chaetiger 13. One of the examined specimens is developing a head behind chaetiger 13. Okada (1933a) found that atokes without pigmentation pattern ( P. scapularis ) also produced stolons without pigmentation pattern, and that atokes with pigmentation pattern (P. p i c t a) produced pigmented stolons. Descriptions of stolons are lacking. Reproductive period between April and September ( Okada 1933a).

Habitat. Hydroids and algae.

Distribution. North East Atlantic, Mediterranean.

Remarks. See remarks for P. p i c t a. Synonymy of P. megodon is based on both information from literature and examination of type material.

Proceraea setoensis ( Imajima, 1966) comb. n. (Fig. 29A–F)

Autolytus (Regulatus) setoensis Imajima, 1966: 67 –69, fig. 21A–H.

Material examined. Japan: 1 paratype NSMT­Pol P­ 11, Seto, intertidal, May 1964. Diagnosis. Proceraea with serrations on large teeth in trepan; unidentate compound chaetae present in anterior three chaetigers.

Description. Paratype with regenerating posterior end consisting of a few small achaetous segments; length 3.2 mm for 13 chaetigers, width 0.5 mm. Preserved material yellowish without colour markings, eyes faintly reddish. Live specimens orange, without colour markings ( Imajima 1966). Ciliation not possible to assess.

Eyes confluent (Fig. 29A); eye spots absent. Palps in dorsal view projecting c. 1/4 of prostomial length (Fig. 29A), fused. Extension of nuchal epaulettes to half of chaetiger 1.

Median antenna reaching chaetiger 8–9. Lateral antennae and dorsal tentacular cirri, length 2/3 of median antenna. Ventral tentacular cirri 1/3 as long as dorsal pair. First dorsal cirri as long as median antenna, second dorsal cirri as long as or ventral tentacular cirri. From chaetiger 3–13 cirri with usual alternation in direction. Dorsal cirri from chaetiger 3, of equal length, 1/3 of body width. Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded, of small–medium size. Aciculae numbering 2–3 in all chaetigers. Chaetal fascicle with 10–12 compounds. Chaetiger 1 with 6 inferior unidentate compound chaetae (Fig. 29C), and 6 superior bidentate (Fig. 29D); chaetiger 2 with 4 inferior unidentate chaetae, and 8 superior bidentate; chaetiger 3 with 3 inferior unidentate chaetae, and 9 superior bidentate; from chaetiger 4 all compound chaetae bidentate (Fig. 29E). Compound chaetae with small distal tooth, especially in chaetiger 1–3; serration absent. Single thick bayonet chaetae beginning at chaetiger 7 (Fig. 29F).

Pharynx with a long sinuation with several small sinuations anterior to and along most of proventricle (Fig. 29A). Trepan in chaetiger 2 (Fig. 29A), with 18 unequal teeth, 9 large tricuspid teeth and 9 smaller; 1 large alternating with 1 smaller (Fig. 29B), in 2 rings. Basal ring present; infradental spines absent. Proventricle equal in length to 2 segments in chaetiger 7–8 (Fig. 29A) with 23 rows of muscle cells. Pygidium regenerating with 2 small anal cirri.

Reproduction. Indications on schizogamy by anterior scissiparity. The paratype is regenerating a posterior end behind chaetiger 13, which is the normal situation in taxa with anterior scissiparity.

Habitat. Intertidal.

Distribution. North West Pacific. Southern Japan, only known from type locality.

Remarks. Proceraea setoensis is unique in its trepan structure with large teeth tricuspid. Its possession of unidentate compound chaetae in anterior chaetigers is a feature shared only with Proceraea vulgaria Imajima, 1966 .

Proceraea vulgaria ( Imajima, 1966) comb. n. (Fig. 30A–F)

Autolytus (Regulatus) vulgarius Imajima, 1966: 59 –61, fig. 17A–J; 1967: 416–417. Autolytus monoceros Fauvel 1934: 313 –314.

Material examined. Japan: 1 paratype NSMT­Pol P­ 20, Usa, intertidal, Jun 1964. Diagnosis. Proceraea with unidentate compound chaetae in anterior 3 chaetigers, nuchal epaulettes reaching end of chaetiger 1.

Description. Paratype complete, length 9 mm for 56 chaetigers, width 0.4 mm. Preserved material yellowish without colour markings, eyes faintly reddish. Live specimens orange, without colour markings ( Imajima 1967). Ciliation not possible to assess.

Eyes large, almost confluent (Fig. 30A); eye spots present. Palps in dorsal view projecting 1/4 of prostomial length (Fig. 30A), fused. Extension of nuchal epaulettes to end of chaetiger 1 (Fig. 30A).

Median antenna reaching chaetiger 7–8. Lateral antennae and dorsal tentacular cirri, length c. 3/4 of median antenna. Ventral tentacular cirri c. 1/3 as long as dorsal pair. First dorsal cirri as long as median antenna, second dorsal cirri 1/2 as long as dorsal tentacular cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length, 1/3 of body width. Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded conical, small to medium in size. Anterior chaetigers with 3–4 aciculae, 1–2 in median and posterior. Chaetal fascicle with 10–12 compounds in anterior chaetigers, 5–10 in median and posterior. Chaetiger 1 with all compound chaetae unidentate; chaetiger 2 with 6 unidentate chaetae and 6 slightly bidentate (Fig. 30C); chaetiger 3 with 2 unidentate chaetae and 10 slightly bidentate (Fig. 30D); more posterior chaetigers with only bidentate compound chaetae (Fig. 30E). Uni­ and bidentate chaetae in chaetiger 2 and 3 mixed with no obvious order. Compound chaetae with small distal tooth; minute serration sometimes present on bidentate compound chaetae (Fig. 30D, E). Single thick bayonet chaetae (Fig. 30F), beginning at c. chaetiger 50.

Pharynx with sinuation anterior and lateral to anterior half of proventricle. Trepan in chaetiger 2, with 18 unequal teeth, 9 large and 9 smaller; 1 large alternating with 1 small (Fig. 30B), arranged in 2 rings. Basal ring present; infradental spines absent. Proventricle equal in length to 4–5 segments in chaetiger 6–9 with 51 rows of muscle cells. Anal cirri equal in length to dorsal cirri.

Reproduction. Schizogamy by anterior scissiparity ( Imajima 1966) behind chaetiger 16 (n=1).

Habitat. Intertidal.

Distribution. North West Pacific. Japan, common in Honshu and Shikoku.

Remarks. A typical Proceraea that may be identified on the unidentate chaetae present in anterior chaetiger 1–3, a feature shared with P. setoensis . However the trepans differ in that P. setoensis has additional small serrations on its large trepan­teeth; the nuchal epaulettes are somewhat longer in P. vulgaria reaching end of chaetiger 1 compared with middle of chaetiger 1 in P. setoensis ; in addition the pharynx has several sinuations lateral to proventricle in P. setoensis , compared with only 1 sinuation anterior to it, in P. vulgaria . According to Imajima (1966) Fauvel's specimens of A. monoceros belong to this taxon.