Pseudofabriciola rousei, Fitzhugh, 2002

Fitzhugh, K., 2002, New species of Fabricinuda Fitzhugh and Pseudofabriciola Fitzhugh (Polychaeta: Sabellidae: Fabriciinae), with an emendation of Pseudofabriciola australiensis (Hartmann-SchroÈder), Journal of Natural History 36 (8), pp. 893-925 : 904-906

Pseudofabriciola rousei n. sp.

(®gures 4, 5; tables 4, 6)

Material examined. Indian Ocean, Western Australia, Shark Bay, Denham. HOLOTYPE: LACM-AHF 2005 , 200 ± 300 m oOE Denham beach, south of jetty, encrusting mats of algae scraped oOE razor oyster and pearl oyster shells on sandy bottom, depth less than 2 m, 21 April 1995, coll. G. W. Rouse. PARATYPES: LACM- AHF 2006 , same locality as holotype, six complete specimens and two specimens without branchial crowns .

Description. Holotype complete (sex unknown) with eight thoracic and three abdominal setigers. Branchial crown length 1.00 mm, remainder of body 2.60 mm long, maximum width 0.25 mm. Body slender, slightly tapering posteriorly (®gure 4A). Branchial crown with three pairs of radioles, distal ends ®lamentous, same width as pinnules. Radioles with six to seven pairs of pinnules, all terminating at about same height, at about one-third total length of radioles. Dorsal lips poorly developed as low, broadly rounded shelf-like processes (®gure 4B). Ventral lips absent. Ventral ®lamentous appendages absent. Dorsal margins of branchial lobes not fused to one another; lobes very elongate, narrowing proximally to short, peduncle-like stalk (®gure 4B). Lobes slightly curved, placing crown in dorsally directed attitude (®gure 4A). Branchial hearts present. Mid-dorsal medial lobe just ventral to mouth well developed, terminating just below collar margin (®gure 4C). Anterior margin of anterior peristomial ring a well-developed, entire, membranous collar of even height all around (®gures 4A, 5). Dorsolateral collar margins with shallow, V-shaped incisions (®gure 5A); mid-dorsal collar margin entire, broadly rounded. Mid-dorsal length of collar slightly thickened, remainder of collar of even thickness. Collar about same length as anterior peristomial ring. Annulation between collar and anterior peristomial ring visible dorsally. Length of anterior peristomial ring plus collar about same length as posterior peristomial ring. Annulation between rings visible all around (®gure 5). Pair of round black eyes at posterior margin of anterior peristomial ring. Setiger 1 slightly longer than posterior peristomial ring, wider than long; setigers 2±4 each about same length as setiger 1 or slightly longer; setigers 5±8 each two to three times longer than setiger 4. Setiger 9 slightly longer than anterior thoracic setigers, with setigers 10±11 each slightly shorter than 9. Pygidium about same length as setiger 11, posterior margin slightly tapered, rounded. Pair of round, black pygidial eyes (®gure 4A). Superior thoracic notosetae elongate, narrowly hooded, three to six per fascicle. Inferior thoracic notosetae in setigers 2± 8 elongate narrowly hooded, two to three per fascicle. Abdominal neuropodia of setigers 9±11 with very elongate, narrowly hooded setae, two to three per fascicle. Thoracic uncini acicular, main fang slender (®gure 4D); teeth behind main fang slender and slightly decreasing in size away from fang; hood present; six to nine uncini per fascicle in irregular single rows. Abdominal uncini with seven to eight rows of teeth in pro®le, three to ®ve teeth per row (®gure 4E); manubrium about 1.5 times longer than dentate region, slightly expanded proximally; uncini in setigers 9±11 number 27, 28 and 18, respectively. Anus midventral, along anterior margin of pygidium. Distribution of male and female gametes not determined. Preserved specimens white, no pigmentation on crown or body wall. Tubes unknown. Brooding of young not observed.

Etymology. It is a great honour to name this species after Dr Greg Rouse, who has made numerous contributions to sabellid systematics.

Remarks. Pseudofabriciola rousei is most similar to P. peduncula Fitzhugh, 1996 , P. so X a Fitzhugh, 1996 and P. W laris n. sp. in that the collar margin only has a single pair of dorsolateral, V-shaped notches, with no mid-dorsal notch or incision (®gure 5A; table 4). All four species also have dorsal lips as low, narrow ridges, and ventral ®lamentous appendages are absent. Within this species group, P. rousei is similar to P. so X a in that both have a medial lobe dorsal to the mouth that extends to near the collar margin (cf. ®gure 4C, Fitzhugh, 1996: ®gure 7B), whereas this lobe is very low in P. peduncula and P. W laris. Pseudofabriciola rousei diOEers from P. so X a in having a larger number of thoracic uncini, six to nine as opposed to three to four. Relative to habitat, P. rousei occurs at intertidal depths, whereas P. so X a is only known at 26 m depth in the Gulf of Mexico ( Fitzhugh, 1996). The relationship of P. rousei to other species in the genus is presented in the cladistic analysis below.

Pseudofabriciola rousei occurs at the same locality as the specimen of P. australiensis described above.