Semiodera tovarae, Salazar-Vallejo, 2012

Salazar-Vallejo, Sergio I., 2012, 3562, Zootaxa 3562, pp. 1-62 : 36-38

Semiodera tovarae n. sp.

Figure 14

Type material. Eastern Tropical Pacific. Holotype ( ECOSUR140 ) and paratypes ( ECOSUR 141 ), El Caimancito, La Paz Bay (24º08'32" N, 110º18'39" W), Baja California Sur, México, 1.5 m, 29 Feb. 2004, P. Salazar, coll. (complete paratypes 10–16 mm long, 1.5–2.0 mm wide, cephalic cage 6.0 (damaged)– 7.5 mm long, 42–62 chaetigers; oocytes 100 µm).

Additional material: Eastern Tropical Pacific. Baja California Sur, México.

One specimen ( ECOSUR 2037 ), anterior fragment, damaged, with a longitudinal dissection, El Requesón, Bahía Concepción (26.67075º N, 111.81359º W), 1 m, 8 Apr. 1982, SISV, coll. One specimen ( ECOSUR 2026 ), juvenile, integument detached, dorsal shield broken, El Requesón, Bahía Concepción , 1 m, 14 Abr. 1983, SISV, coll. (9 mm long, 1 mm wide, cephalic cage 5 mm long, 44 chaetigers). One specimen ( ECOSUR), dorsal shield broken, head exposed, several parapodia removed, breaking into two parts, El Caimancito, La Paz Bay (24º08'32" N, 110º18'39" W), 1.5 m, 28 Nov. 1986, SISV, coll. (13.5 mm long, 2 mm wide, cephalic cage 7.5 mm long, 50 chaetigers; right gonopodial slit swollen, darker). Three specimens ( ECOSUR 2038 ), one inside a piece of calcareous rock, El Caimancito, La Paz Bay , 1.5 m, 2 Mar. 2004, P. Salazar, coll. (complete 11.5 mm long, 2 mm wide, cephalic cage 5 mm long, 50 chaetigers). One specimen ( ECOSUR 2036 ), without posterior region, El Caimancito, La Paz, 1 m, 2 Mar. 2004, P. Salazar, coll. One specimen ( ECOSUR 2028 ), without posterior region, El Caimancito, La Paz, 1 m, 3 Mar. 2004, P. Salazar, coll. (mature male; testis lobes pale; anterior chaetigers slightly pigmented ventrally). One specimen ( ECOSUR 2027 ), twisted, depressed, Loreto Harbor, Loreto, 2 m, 3 Mar. 2004, P. Salazar, coll. (14 mm long, 2.5 mm wide, cephalic cage 6 mm long, 69 chaetigers). One specimen ( ECOSUR 2033 ), juvenile, El Caimancito, La Paz, 1 m, 6 Mar. 2004, P. Salazar, coll. (8 mm long, 1 mm wide, cephalic cage 4 mm long, 44 chaetigers). Sinaloa, México. One specimen ( ECOSUR 2029 ), Southern Point, Isla Venado, Mazatlán (23º14'29" N, 106º24'35" W), 2 m, 26 Feb. 2004, P. Salazar, coll. (17 mm long, 2 mm wide, cephalic cage 5 mm long, 69 chaetigers). Nayarit, México. Three specimens ( ECOSUR 2035 ), juveniles, Aticama, 2 m, 25 Nov. 2004, P. Salazar, coll. (complete 9 mm long, 1 mm wide, cephalic cage (anterior fragment) 3 mm long, 43 chaetigers). Jalisco, México. One specimen ( ECOSUR 2031 ), juvenile, Melaque (19º13'31" N, 104º42'04" W), 1 m, 1 Dec. 2004, P. Salazar, coll. (6 mm long, 1 mm wide, cephalic cage 4.5 mm long, 45 chaetigers; anterior chaetigers without dark pigment ventrally). One specimen ( ECOSUR 2030 ), juvenile, Melaque, Andador, 1 m, 2 Dec. 2004, P. Salazar, coll. (6 mm long, 1 mm wide, cephalic cage 4 mm long, 43 chaetigers; anterior chaetigers without dark pigment ventrally). One specimen ( ECOSUR 2034 ), mature specimen, without posterior end, Barra de Navidad (19º12'29" N, 104º40'50" W), 1 m, 3 Dec. 2004, P. Salazar, coll. (few anterior chaetigers with dark pigment ventrally). Would be good to add lats and longs to all these sites and obtain registration nos .

Description. Holotype (ECOSUR 140) whitish ( Fig. 14A), with an anterior, ventral dark transverse band over chaetigers 1–2, fading in following chaetigers ( Fig. 14B). Body tapering into a cylindrical, thin cauda; 21 mm long, 2 mm wide, cephalic cage (damaged) 7.5 mm long, 65 chaetigers. Tunic thin, without sediment cover; body papillae short, digitate, arranged in 2–3 irregular transverse bands per segment, each with abundant papillae, alternating large and small.

Cephalic hood not exposed; anterior end observed in one paratype. Prostomium low cone, four black eyes, anterior ones free from each other, posterior ones coalescent. Caruncle poorly developed, not separating branchiae. Palps long, pale; palp keels rounded, low. Lips distorted by contraction, not separable in lateral, dorsal or ventral views.

Branchiae cirriform, sessile on branchial plate, arranged in single, curved row, with 14 filaments, decreasing in size ventrally, largest about as long as palps. Nephridial lobes placed below second dorsalmost branchiae, as thick as smaller branchial filaments.

Cephalic cage chaetae damaged, as long as 1/3 body length (about half as long in some paratypes), or about four times longer than body width. Chaetigers 1–2 involved in the cephalic cage; chaetiger 3 with chaetae longer than those present in following chaetigers, but not contributing to the cage. Chaetae arranged in short, ventrolateral rows; chaetiger 1 with 4 noto- (8 in paratypes), and 8 neurochaetae, chaetiger 2 with 4 noto- and 4 neurochaetae per bundle.

Anterior dorsal margin of first chaetiger papillated without lobes (probably eroded). Anterior chaetigers without longer papillae on chaetal lobes. Chaetigers 1–3 progressively smaller; chaetiger 3 about as long as following chaetigers. Sand cemented anterior shield dorsal, rugose (lost in some specimens), extend over chaetigers 1–4 ( Fig. 14A, insert), continued laterally. Chaetal transition from cephalic cage to body chaetae gradual; chaetigers 4–6 with two pseudocompound hooks (up to 3 in juveniles, from chaetiger 3), becoming smaller, pseudoarticulation progressively fading in posterior chaetigers ( Fig. 14C); falcate neurohooks from chaetiger 7. Gonopodial slits barely visible in chaetiger 5, slightly darker than surrounding body wall surface.

Parapodia poorly-developed, chaetae emerge from body wall. Parapodia lateral, median neuropodia ventrolateral. Noto- and neuropodia low lobes, with long digitate interramal papillae in anterior and median chaetigers; posterior chaetigers with papillae similar, digitate, longer. Noto- and neuropodia well separated.

Median notochaetae arranged in short, transverse rows; all notochaetae multiarticulate capillaries, about 1/3 as long as body width, 3 per fascicle, articles long, continue to chaetal tip. Neurochaetae multiarticulate capillaries in chaetigers 1–3; chaetigers 4–6 with two pseudocompound hooks. Falcate neurohooks from chaetiger 7, arranged in transverse rows, 3–4 (mostly) per bundle in median chaetigers ( Fig. 14D), decreasing to 1–2 in posterior chaetigers. Each hook markedly falcate, tapered, barely widened medially, becoming thinner in posterior chaetigers ( Fig. 14E).

Posterior end tapering to rounded lobe; pygidium with terminal anus, without anal cirri.

Etymology. This species is being named after Dr. María Ana Tovar Hernández, a distinguished specialist of sabellid polychaetes, in recognition of her fine publications and her support of my taxonomic studies.

Type locality. El Caimancito Beach, La Paz Bay , La Paz, Baja California Sur .

Remarks. Semiodera tovarae n. sp., resembles S. blakei n. sp. and S. dubia ( Treadwell, 1929) n. comb. because they all have 2–3 rows of papillae, smooth integument and four neurohooks per bundle in median chaetigers. It has been shown above that S. blakei can be separated by the earlier start of falcate neurohooks (chaetiger 6 vs chaetiger 7), and because it has large papillae over anterior chaetigers.

Semiodera tovarae closely resembles S. dubia . They differ because in S. tovarae the dorsal shield is laterally projected and has tapered neurochaetae, whereas in S. dubia the shield is restricted to the dorsal surface, and its neurochaetae are subdistally swollen.

Distribution. Southern Gulf of California to Jalisco, México, in shallow water, in harbors or shallow water environments.