Semiodera glynni, Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, 3562, Zootaxa 3562, pp. 1-62 : 21-23

Semiodera glynni n. sp.

Figure 6

Type material. Eastern Tropical Pacific, Gulf of Panama. Holotype (USNM-1191186) and seven paratypes (USNM-1191187), Isla Señorita, Islas de las Perlas (08º20' N, 79º07' W), Panama, Stat. 68, dead basal portions of corals, 19 Jun. 1971, P. Glynn & M.E. Rice, coll. Paratypes three complete specimens and three anterior fragments (+ 1 post. fragm.). Size: trunk + cephalic cage, and (first chaetiger) with first (entire?) neurohooks: 8+2(6), 12+3.5(7), 13+3(7), 13+3(7), 15+4(5), 17+3(6), 17+4(7), 21+5(7).

Additional material: Eastern Tropical Pacific. México. Baja California Sur. One specimen ( ECOSUR 2032 ), mature female, ovary extruded, Presidente, El Caimancito , La Paz Bay (24º08'32" N, 110º18'39" W), 1.5 m depth, 28 Nov. 1986, SISV, coll. (16 complete mm long, 2 mm wide, cephalic cage 7 mm long, 62 chaetigers; oocytes 125– 150 µm). Seven specimens ( ECOSUR 1764 ), five complete, El Caimancito, La Paz Bay , 2 m depth, 8 Oct. 1987, J.A de León & SISV, coll. (7–14 complete mm long, 1–2 mm wide, cephalic cage 6–8 mm long, 43–44 chaetigers; largest without dorsal shield particles). Four specimens ( ECOSUR), three complete, with rusty or dark orange spots, Loreto Harbor (26º00'46" N, 111º20'36" W), 1 m, 3 Mar. 2004, P. Salazar, coll. (17.5–20.0 mm long, 2 mm wide, cephalic cage 9.5–10.0 mm long, 60–67 chaetigers). One specimen ( ECOSUR), La Paz, 2 Mar. 2004, P. Salazar, coll. (9.5 mm long, 1.8 mm wide, cephalic cage 6 mm long, 51 chaetigers). One specimen ( ECOSUR), nuchal shield without sediment particles, Marina La Paz , M.A. Tovar, 14 Aug. 2011 (mature male; 11 mm long, 2 mm wide, cephalic cage 7 mm long, 52 chaetigers) . Sinaloa. Three specimens ( ECOSUR 1766 ), one complete, two others incomplete, Eastern shore, Isla Venados , Mazatlán (23º14'29" N, 106º24'35" W), 2 m depth, 26 Feb. 2004, P. Salazar, coll. (11 mm long, 1.8 mm wide, cephalic cage 5 mm long, 50 chaetigers). Two specimens ( ECOSUR 1767 ), one complete, both extruding their enteron, Playa Pinitos, Mazatlán, 4 m depth, on rock oyster, 27 Feb. 2004, P. Salazar, coll. (complete 22 mm long, 1.5 mm wide, cephalic cage 4.5 mm long, 86 chaetigers) . Nayarit. Six specimens ( ECOSUR 1768 ), juveniles, three complete, Aticoma, 1 m depth, 25 Nov. 2004, P. Salazar, coll. (complete 3–9 mm long, 0.5–1.5 mm wide, cephalic cage 2.5–4.0 mm long, 22–39 chaetigers). One specimen ( ECOSUR), anterior fragment, anterior end exposed, Sayulita (20º52'08" N, 105º26'27" W), 28 Nov. 2004, B. Yáñez & P. Salazar, coll. Two specimens ( ECOSUR), one complete, Playa La Manzanilla , 1 m depth, 29 Nov. 2004, P. Salazar, coll. (8 mm long, 0.8 mm wide, cephalic cage 4 mm long, 42 chaetigers) . Jalisco. Seven specimens ( ECOSUR), four complete, Melaque (19º13'31" N, 104º42'04" W), Andador , 1 m depth, 2 Dec. 2004, P. Salazar, coll. (complete 5.5–15 mm long, 1.0– 1.5 mm wide, cephalic cage 5.0– 5.5 mm long, 51–63 chaetigers; mature females with oocytes 100–125 µm). One specimen ( ECOSUR), Barra de Navidad , 1 m depth, 3 Dec. 2004, P. Salazar, coll. (9.5 mm long, 1 mm wide, cephalic cage 3 mm long, 83 chaetigers) . Guerrero. One specimen ( ECOSUR), mature female, Manzanillo, Acapulco (16º51'42" N, 99º53'11" W), 2 m, 4 Aug. 1988, N.E. González & SISV, coll. (27 mm long, 2 mm wide, cephalic cage 5 mm long, 100 chaetigers; oocytes 100 µm). One specimen ( ECOSUR), Cantiles, La Quebrada, Acapulco, 2 m, 26 May 2000, A. Medina, coll. (complete 9 mm long, 1 mm wide, cephalic cage broken, 3 mm long, 70 chaetigers; neurohooks dark, rarely three per bundle) . Oaxaca. One specimen ( ECOSUR), without posterior end, Puerto de Abrigo, Huatulco (15º50'03" N, 96º19'20" W), 1 m, 22 May 2000, SISV, coll. Gulf of Panama. Fifteen specimens ( USNM 1177520 ), eight complete, others partially dried-out, Paitilla Beach , 28 Oct. 1970, A.A. Reimer, coll. (complete 9.0– 15.5 mm long, 1.0– 3.5 mm wide, cephalic cage 3.5–6.0 mm long, 56–66 chaetigers; mature females with a darker background). Throughout this please give lats and longs –so people could go back and recollect .

Description. Holotype (USNM-1191186) white, with anterior end everted, cylindrical, tapering posteriorly ( Fig. 6A); 14 mm long, 1 mm wide, cephalic cage 3 mm long, 51 chaetigers. Tunic thin, without sediment particles; body papillae small, digitate, arranged in 3 irregular rows per segment.

Cephalic hood very short, barely exposed, margin papillated. Prostomium low cone with four medium-sized, dark-brown eyes, not coalescent (larger, coalescent in mature non-type specimens). Caruncle not projected dorsally. Palps lost in holotype (in some paratypes as long as branchiae, slightly thicker than thickest branchiae, Fig. 6C); palp keels rounded, elevated. Lateral lips rounded, well developed.

Branchiae cirriform, sessile on branchial plate, decreasing in size laterally; 6 larger, distal filaments, 3–4 proximal smaller filaments per side. Nephridial lobes as long as and as wide as thinner branchiae, arise internally below distal larger branchiae.

Cephalic cage chaetae 1/5 as long as body or three times longer than body width. Chaetigers 1–2 forming the cephalic cage. Cephalic cage chaetal arranged in short lateral and ventral rows on each chaetiger; four chaetae per bundle in chaetiger 1, three in chaetiger 2.

Anterior dorsal margin of first chaetiger slightly damaged in holotype, with a median trifid (or multifid) lobe. Anterior chaetigers with long papillae restricted to chaetal lobes. Chaetigers 1–2 of about the same length, chaetiger 3 longer. Sand cemented anterior shield thin, oval, flat, dorsal; particles small, embedded, extending over chaetigers 1–4 in holotype ( Fig. 6B), thicker, extending up to chaetiger 5 in paratypes. Chaetal transition from cephalic cage to body chaetae gradual; pseudocompound hooks in chaetigers 4–6 ( Fig. 6E–F) (3–5 in the smallest paratype). Simple falcate neurohooks from chaetiger 7. Gonopodial slits present in chaetiger 5, transverse fusiform low cushions; one paratype with a slightly everted, dark lobe ( Fig. 6D).

Parapodia poorly developed; only chaetigers 1–2 with projected lobes and long papillae; others with chaetae emerging from the body wall. Parapodia lateral, neuropodia ventrolateral. Notopodia with a long digitate papilla ( Fig. 6G, H). Neuropodia without long papillae. Noto- and neuropodia close to each other.

Median notochaetae arranged in transverse tufts. Notochaetae of median chaetigers multiarticulate capillaries, articles long; about as long as ¼ or 1/5 body width, two per fascicle. Neurochaetae multiarticulate capillaries in chaetigers 1–3, pseudocompound hooks in chaetigers 4–6, simple falcate hooks from chaetiger 7. Falcate neurohooks arranged in a J-pattern, mostly 3 per fascicle ( Fig. 6G, H); up to four by chaetiger 12, decreasing afterwards.

Posterior end tapering; pygidium conical, blunt, without anal cirri.

Etymology. This species is named after Dr. Peter Glynn, who has devoted most of his research activities to coral environments in the Gulf of Panama, and also because he collected the specimens.

Variation: The four complete paratypes included two mature females (12.5–13 mm long); they were 12.5–17.0 mm long, 1.0– 1.5 mm wide, cephalic cage 3–4 mm long, 53–62 chaetigers. Some anterior fragments belonged to larger specimens, two of them were mature females; they were 1.0– 2.5 mm wide with cephalic cage 3.5–5.5 mm long.

Remarks. Semiodera glynni n. sp. groups with S. curviseta ( Caullery, 1944) and S. villalobosi n. sp. because they have reduced dorsal shield and carry 3–4 neurohooks per ramus. As stated above, S. curviseta differs from the two other species because the neurohooks start in chaetiger 8, instead of chaetigers 6 or 7. Thus, S. glynni is more closely allied to S. villalobosi ; they differ, in that S. glynni has the dorsal shield restricted to the dorsal surface and has three transverse rows of papillae per segment, whereas in S. villalobosi the shield extends laterally and ventrally and there is only one row of papillae present per segment.

Distribution. Only known from the type locality, boring coral substrates in shallow waters of the Gulf of Panama.