Proceraea paraurantiaca Nygren, 2004, sp. n.

Proceraea paraurantiaca sp. n. (Fig. 22A–F)

Proceraea aurantiaca Nygren & Gidholm 2001: fig. 3D.

Proceraea sp2 Nygren & Sundberg 2003: GenBank sequences, 16S rDNA partial sequence AF474277, and 18S rDNA partial sequence AF474323.

Material examined. Spain: holotype SMNH 5948 and 4 additional spms (2 spms on slides (rear ends in author's collection for DNA analyses), 2 spms in author's collection for DNA analyses), El Caboda, Trafalgar, 36°11'N 6°01'W, dive, 5 m, Corallina sp., Codium sp., sponges, hydroids, Nov 1999. France: 2 spms (1 mounted for SEM, 1 in author's collection for DNA analyses), Banyuls­sur­Mer, 42°28.9'N 03°08.2'E, sponges, hydroids, dive, 10 m, May 1997; 1 spm, Banyuls­sur­Mer, 42°28.9'N 03°08.2'E, dive, 1–3 m, algae, hydroids, 23 Apr 2001; 1 spm, Banyuls­sur­Mer, 42°28.6'N 03°09.7'E, dive, 30 m, "coralligene", 24 Apr 2001.

Diagnosis. Proceraea with well­developed ciliated ridge on palps.

Description. Length 5.2–10 mm for 34–76 chaetigers, width 0.2–0.35 mm. Live specimens faintly yellowish, intestinal region greenish, proventricle yellowish to weekly orange, parapodial bases with one red spot; eyes red. Preserved specimens without colours. Ciliation present on prostomium, nuchal epaulettes, and a few segments ventrally.

Eyes confluent (Fig. 22A); eye spots present (Fig. 22B). Palps in dorsal view projecting 1/3–1/2 of prostomial length (Fig. 22A, B), fused. Palps with an extra ridge, well ciliated (Fig. 22B). Nuchal epaulettes extending over anterior part of chaetiger 1 (Fig. 22A, B).

Median antenna reaching chaetiger 12–20 (n=4) in live specimens. Lateral antennae and dorsal tentacular cirri, length 1/2 of median antenna. Ventral tentacular cirri 1/2 as long as dorsal pair. First dorsal cirri as long as or 2/3 of median antenna, second dorsal cirri as long as 1.5 times the tentacular cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length, 1/2 of body width. Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded conical, small. Anterior chaetigers with 2 aciculae, 1 in median and posterior. Chaetal fascicle with 8–10 compounds in anterior chaetigers, 4–7 in median and posterior. Compound chaetae with small distal tooth in anterior 5–15 chaetigers (Fig. 22C), more posterior with large distal tooth (Fig. 22D). Single thick bayonet chaetae (Fig. 22E) beginning between chaetiger 4–15 (n=4).

Pharynx with short sinuation anterior to proventricle. Trepan in chaetiger 1–2 (Fig. 22A, B), with 18 unequal teeth, 9 large and 9 smaller; 1 large alternating with 1 small, arranged in 2 rings (Fig. 22F). Basal ring present; infradental spines absent (Fig. 22F). Proventricle equal in length to 2–3 segments in chaetiger 7–10 (Fig. 22A) with 31–38 rows of muscle cells (n=7). Anal cirri equal in length to c. body width.

Reproduction. Unknown.

Habitat. Hydroids, bryozoans, algae, 5– 30 m.

Distribution. North East Atlantic, Mediterranean.

Etymology. Named for its similarity with P. aurantiaca.

Remarks. Proceraea paraurantiaca is a rather cryptic species, probably confused with P. aurantiaca as was done in Nygren & Gidholm (2001: fig 3D). The most distinctive character that separates the two is that P. paraurantiaca has an additional ciliated ridge on their palps; in addition the pharynx is not as convoluted and the proventricle is generally paler than in P. aurantiaca. Of the sequenced autolytines, P. aurantiaca closest relative is the West Atlantic P. rubroproventriculata Nygren & Gidholm, 2001.

Proceraea penetrans (Wright & Woodwick, 1977) comb. n. (Fig. 23A–E)

Autolytus (Regulatus) penetrans Wright & Woodwick, 1977: 43 –47, figs 2, 3A–D.

Material examined. USA: holotype LACM POLY­ 1176, California, Farnsworth Bank off Santa Catalina Island, and Gull Island off Santa Cruz, within blisters on the hydrocoral Allopora california, 6–18 m depths.

Diagnosis. Proceraea with compound chaetae lacking serration, forms blisters on the hydrocoral Allopora california, in which it lives.

Description. Holotype complete. Length 2.6 mm for 38 chaetigers, width 0.2 mm. Preserved material whitish­greyish with scattered black pigments (Fig. 23A). Ciliation not possible to assess.

Eyes separated; eyes spots absent. Palps in dorsal view projecting 1/4–1/3 of prostomial length, fused. Nuchal epaulettes extending over tentacular segment.

All anterior appendages curled, not evaluated. Cirri on chaetiger 2, length 1.5 times the following cirri. Alternation in direction of cirri not assessed. Dorsal cirri from chaetiger 3, of equal length, 1/4–1/5 of body width excluding parapodia. Cirrophores on tentacular segment and first dorsal cirri present; cirrophores otherwise absent. All appendages cylindrical.

Parapodial lobes rounded conical, small (Fig. 23A). Single acicula in all chaetigers. Chaetal fascicle with 7–8 compounds in anterior chaetigers, 4–5 in median and posterior. Compound chaetae with small distal tooth; serration absent (Fig. 23D, E). Single thick bayonet chaetae, beginning at chaetiger 7.

Pharynx with 1 sinuation anterior to the proventricle. Trepan in chaetiger 3, with 18 unequal teeth, 9 large and 9 slightly smaller (Fig. 23C); 1 large alternating with 1 small, in 2 rings. Absence/presence of basal ring and infradental spines not possible to assess. Proventricle equal in length to 2.5 segments in chaetiger 7–9, with 34 rows of muscle cells (Fig. 23B). Anal cirri equal in length to 1/8 of body width.

Reproduction and morphology of epitokous stages. Schizogamy, indications on anterior scissiparity. Body segments behind chaetiger 13 thinner. Possibly small antennae developing behind chaetiger 13. Wright & Woodwick briefly describes a male stolon: length 2 mm for 6+19+10 chaetigers.

Habitat. In blisters on the hydrocoral Allopora california.

Distribution. North East Pacific. California, only known from type locality.

Remarks. Wright & Woodwick described the trepan as having 9 equal teeth, closer inspection revealed a trepan with 18 unequal teeth, 1 large alternating with 1 small, in 2 rings, typical of most Proceraea. Other Proceraea ­species with similar trepan, with nuchal organs only extending over tentacular segments and small distal tooth in compound chaetae include Proceraea cornuta, P. micropedata, P. okadai, P. nigropunctata, and P. okadai. Proceraea penetrans may be separated from these by examination of the compound chaetae. The progenitor chaetae (Wright & Woodwick 1977, fig. 3C) could not be found, but the compound chaetal blades lack serration and the distal tooth is less developed in P. p e n ­ etrans than in all mentioned species (compare Fig. 23D with e.g. Fig. 20D). Proceraea penetrans is interesting as it forms blisters on the hydrocoral Allopora california, in which it lives. Autolytines are for what is known, mostly less associated with their hosts; there is one other report of commensal/parasitic behaviour in the autolytine Proceraea rhavskyi (see remarks for Epigamia alexandri (Malmgren, 1867)) where the theca of Abietinaria is modified to host the developing larvae.