Halosydna latior Chamberlin, 1919

Salazar-Silva, Patricia, 2013, Revision of Halosydna Kinberg, 1856 (Annelida: Polychaeta: Polynoidae) from the Tropical Eastern Pacific and Grand Caribbean with descriptions of new species, Journal of Natural History 47 (17 - 18), pp. 1177-1242 : 1196-1199

Halosydna latior Chamberlin, 1919

( Figures 9 , 10 )

Halosydna latior Chamberlin, 1919a: 1–2 .

Halosydna obtusa-cirrata Treadwell, 1937: 143–144 , plate 1, figures 8–11.5.

Halosydna latior: Hartman, 1939a: 32 ; Salazar-Silva, 2006: 148.

Halosydna brevisetosa: Skobsberg, 1942: 482–489 (non Kinberg, 1856).

Type material

Holotype ( MCZ 2138) of Halosydna latior, Mussel Point, Laguna Beach , California, USA, coll. Hamilton, Field # PO 3. One paratype ( AMNH 2379) of Halosydna obtusacirrata Treadwell, 1937 , East of Cedros Island, Baja California Sur, Mexico, 73.15 m, dried, 22 May 1936.

Additional material

Three specimen ( LACM-AHF POLY 2387 ) of Puerto San Carlos, Sonora, Mexico, 27 ◦ 57 ′ 15 ′′ N, 111 ◦ 04 ′ 45 ′′ W, rock shingle, shore, R / V Velero III, station 1091-40, 8 February 1940, coll. Allan Hancock Foundation. Commensal worm, found in shells with large hermit, commensal in shell apex inhabited by Petrochiros californiensis, Bouvier, id. as H. latior .

Description

Holotype with 36 segments, 4.1 cm long, 1.2 cm wide, subrectangular in cross-section, pigmentation absent. Prostomium bilobed, as wide as long, slightly retracted into segment 2; lobes slightly separated, rounded, without peaks; facial tubercle short and rounded; two pairs of eyes, anterior pair on widest part of prostomium; posterior pair near posterior margin; median antenna with ceratophore inserted frontally, style subdistally expanded and ring of pigmentation, distally tapering to fine tip; lateral antennae with ceratophores inserted terminally as prolongations of prostomium lobes, styles similar to median antenna. Palps smooth, papillae absent. Pharynx not everted.

Tentacular segment not visible dorsally; tentaculophores lateral to prostomium, chaetae absent; tentacular cirri similar to antennae. Segment 2 with two small tubercles dorsally. First pair of elytrophores lateral to prostomium, prominent.

Body with 18 pairs of elytra, on segments 2, 4, 5, 7, 9, 11, then alternate to 21, 23, 25, 27, 28, 30, 31, 33. Three posteriormost segments with dorsal cirri. First pair of elytra missing. Second pair reniform ( Figure 10A ). Elytra in median and posterior segments oval. All elytra with fringe of short and thick marginal papillae; surfaces granular, with microtubercles and macrotubercles. Microtubercles conicalblunt ( Figure 9A ), scattered over entire surface. Macrotubercles over elytrophore scar, larger, circular as flattened disc-shape ( Figure 9B ).

Notopodia shorter than neuropodia ( Figure 9C ). Neuropodia distally truncate, prechaetal lobe with small rounded lobe near acicular tip. Dorsal cirri reaching neurochaetae tips, with ring of pigment subdistally. Cirrophores basally expanded. Elytrophores wider than dorsal tubercles. Ventral cirri short, not reaching distal neuropodial margin. Nephridial papillae long in median segments. Anus dorsal. Pygidium with anal cirri missing. Notochaetae shorter than neurochaetae; with rows of spines; tapering to capillary tips ( Figure 9D ), the smaller curved with blunt tips. Neurochaetae with rows of spines on upper region, tips entire ( Figure 9E ).

Remarks

The other specimens of H. latior measure from 7.9 cm long and 1.6 cm wide to 1.8 cm long and 0.8 cm wide. However, all coincide with regard to elytra, parapodia and chaetae. The holotype lacks the anterior elytra, which are present in non-type specimens, where the first three pairs show a fringe of marginal papillae ( Figure 10C ), granular surfaces with abundant microtubercles, macrotubercles over the elytrophore scar. The features of the remaining elytra agree with those of the holotype ( Figure 10D–G ). Although the paratype of H. obtusa-cirrata Treadwell, 1937 , is dried, it is possible to distinguish the fringe and microtubercles on all elytra ( Figure 10C–E ) and the macrotubercles on median elytra, like those present in H. latior ( Figure 10E–G ) Hence H. obtusa-cirrata is considered a synonym of H. latior . Halosydna latior was described from Laguna Beach, California, and the records of Hartman (1939a) and the paratype of H. obtusa-cirrata are from Baja California, Mexico. Rioja (1963) recorded the species from Topolobampo, Mexico. Skobsberg (1942) reported H. brevisetosa from Monterey and Carmel Bays, but the features described agree with H. latior .

Type locality

Laguna Beach at Mussel Point, California, USA.

Distribution

Laguna Beach, California, USA; Cedros Island, Baja California Sur, Mexico; Puerto San Carlos, Sonora, Mexico.

Figures

Figure 9. Halosydna latior Chamberlin, 1919a. Holotype MCZ 2138. (A) Microtubercles from elytra of middle segment; (B) same, macrotubercles; (C) parapodium, posterior view; (D) notochaeta, detail; (E) unidentate neurochaetae.

Figure 10. Halosydna latior Chamberlin, 1919a. (A, B) Holotype MCZ 2138. (A) Right elytron of middle segment; (B) same, details. (C–G) paratype AMNH 2379 of Halosydna obtusa-cirrata, (C) first elytron; (D) left elytron from middle segment; (E) right elytron from middle segment; (F) same, macrotubercles; (G) same, microtubercles.