Chaetacanthus harrisae, Salazar-Silva & López-Sánchez & Salazar-Vallejo, 2020

Salazar-Silva, Patricia, López-Sánchez, Daniel A. & Salazar-Vallejo, Sergio I., 2020, Revision of Chaetacanthus Seidler, 1922 (Annelida, Phyllodocida, Polynoidae), Zootaxa 4885 (3), pp. 395-422 : 406-407

Chaetacanthus harrisae n. sp.

urn:lsid:zoobank.org:act:E304CEF1-D40F-404C-89D3-710D8087C618

Figure 9

Lepidonotus pomareae panamensis Hartman 1939a: 44–46 , Pl. 6, Figs 70–77 (partim).

Lepidonotus panamensis: Hartman 1948: 28 (n. status, partim).

Type material. Pacific Panama. Holotype LACM 245-34 , Pacora Island, Panama, 27–45 m, R/ V Velero III, Sta. 245-34, 07°44’19” N, 81°35’23”W, dredged off North West Point Rock , large shells and nullipores, 21 Jul. 1934.

Diagnosis. Chaetacanthus with branchial filaments single, thick lobes; elytra with pale to brownish round spinous macrotubercles; microtubercles bulbous up to three times longer than wide, spinous surface extended along ½– 2 / 3 basal length; elytra without large, amber-colour macrotubercles arranged in honeycomb like groups.

Description. Holotype (LACM 245-34) 5.5 cm long, 1.35 cm wide, 26 segments. Prostomium bilobed with facial tubercle prominent, acute. Two pairs of eyes, anterior pair on widest prostomial area, posterior pair hidden under anterior projection of second segment. Median antenna with ceratophore inserted frontally, style long, subdistally swollen. Lateral antennae with ceratophores inserted frontally, styles similar to median antennal one. Palps with rows of thick papillae. Pharynx not everted.

Tentacular segment not visible dorsally. Tentaculophores thin, tentacular cirri similar to median antenna. Second segment with anterior border projected over prostomium as a short round nuchal lobe.

Elytral margin with fringe of long abundant, filiform papillae ( Fig. 9A ), some with globular tips, including a distinctive bundle of papillae. Elytral surface verrucose with abundant globular, non-sclerotized spinous macrotubercles ( Fig. 9G ), and clavate micropapillae ( Fig. 9B ). First pair of elytra with scattered microtubercles along its whole surface, globular macrotubercles close to elytrophoral plug area ( Fig. 9A, G ). On middle and posterior elytra globular macrotubercles scarce ( Fig. 9F ), spinous surface extended along ½– 2 / 3 basal length, microtubercles numerous, bulbous with long peaks ( Fig. 9 B–E).

Parapodia biramous. Notopodia thick with acicular tips emergent. Neuropodia distally truncate, acicular tips emergent. Branchial filaments present between successive parapodia. Dorsal cirri thin, long, reaching neurochaetal tips, cirri subdistally swollen, resembling antennae. Cirrophores robust. Nephridial papillae long, thick.

Notochaetae thin capillaries, long, with spinous surface, lower notochaetae shorter, slightly curved, serrated. Neurochaetae with upper region short, subdistally with long thin spines, tips entire, long, acute.

Etymology. This species is named after Mrs. Leslie Harris, our long-term friend and teacher, in recognition of her efforts supporting taxonomy of polychaetes, and especially because she has been very generous by housing us during repetitive visits to Los Angeles during the last 20 years.

Remarks. Hartman (1939a) described Lepidonotus pomareae panamensis and indicated its differences from the nominal form by having elytra “conspicuously covered with numerous large headed, high tubercles, the sixth pair of elytra is rectangular, not triangular, and the total length is over 35 mm as against 13 mm specified for L. pomareae .” As indicated below, the holotype of this subspecies, later raised to species level as L. panamensis , is regarded as a junior synonym of C. pilosus ( Treadwell, 1937) . However, the specimen investigated here belongs neither to L. pilosus nor to L. pomareae , and is described here as C. harrisae n. sp. The material was erroneously referred from station 254-34, but it comes from station 245-34.

Further, C. harrisae n. sp. differs from C. pilosus because its elytra do not have pedunculated tubercles, in the first pair of elytra of C. harrisae the macrotubercles are mainly globular, scarce and concentrated along the area corresponding to the elytrophoral plug. In elytra of median and posterior segments, the macrotubercles are smaller, and the microtubercles bear long, tapered peaks.

On the other hand, members of C. harrisae n. sp. also differ from members of C. pomareae ( Kinberg, 1856) in that the latter lacks the long conical tubercles scattered along the posterior elytral half area, and only the anterior elytra have long macrotubercles.

Type locality. Pacora Island , Panamá, in 27–90 m depth .

Distribution. Only known from the original record.

Figures

FIGURE 9. Chaetacanthus harrisae n. sp., holotype (LACM 245). A. First elytron, dorsal view. B. Same, spiny microtubercles. C–E. Same, close up of spiny microtubercles. F. Elytron of middle segment, dorsal view. G. Globular central macrotubercles from first elytron. Scale bars: A, F: 1.1 mm; B, G: 0.1 mm; C: 0.3 mm; D, E: 0.01 mm.