Proceraea bifidentata Ben­Eliahu, 1977

Nygren, Arne, 2004, Revision of Autolytinae (Syllidae: Polychaeta)., Zootaxa 680, pp. 1-314 : 45-46

Proceraea bifidentata Ben­Eliahu, 1977 (Fig. 7A–D)

Procera bifidentata Ben­Eliahu, 1977: 87 –88, fig. 14A–C.

Material examined. Israel: holotype BMNH 1997.1076, Gulf of Elat, Dendropoma habitat, 30 Apr 1971.

Diagnosis. Proceraea with 9 large teeth alternating with 18 smaller in 2 rings, small teeth fused for half their length.

Description. Holotype mounted on slide, length 7.2 mm for 60–70 chaetigers, width 0.7 mm, but specimen compressed. Preserved material without colour markings. Ciliation not possible to assess.

Eyes confluent (Fig. 7A); eye spots present. Palps in dorsal view projecting 1/3 of prostomial length, fused. Nuchal epaulettes not possible to observe.

All antennae and tentacular cirri lost, first left dorsal cirri present, damaged. Dorsal cirri equal in length, 1/6–1/8 of body width. Absence/presence of cirrophores on tentacular cirri, and first dorsal cirri not possible to determine; cirrophores on dorsal cirri that are possible to inspect, absent (Fig. 7B). All appendages cylindrical.

Parapodial lobes rounded, small (Fig. 7B). Anterior chaetigers with 2 aciculae, 1 in median and posterior. Chaetal fascicle with 7–10 compounds. Chaetal blades with small distal tooth (Fig. 7C); serration present. Single thick bayonet chaetae (Fig. 7C), beginning at chaetiger 8.

Pharynx sinuated, lying outside body; position of trepan not known. Trepan with 27 teeth; 9 large and 18 smaller; 1 large alternating with 2 small, arranged in 2 rings (Fig. 7D); small teeth are fused for 1/2 their length. Basal ring present; infradental spines absent (Fig. 7D). Number of rows of muscle cells not possible to assess. Anal cirri lost.

Additional information. Ben­Eliahu described the nuchal epaulettes as covering the tentacular segment, and the proventricle as equal in length to 3 segments in chaetiger 6–8, with 50 rows of muscle cells.

Reproduction. Unknown.

Habitat. Dendropoma infauna.

Distribution. Indian Ocean, Gulf of Elat, only known from type specimen.

Remarks. Proceraea bifidentata is unique among Proceraea to have a trepan with 9 large and 18 smaller teeth. The trepan is very similar to the trepan found in Epigamia noroi Imajima & Hartman, 1964 ; P. bifidentata differs from E. noroi in e.g. the shape of bayonet chaetae.