Ephesiopsis shivae, Rizzo, Alexandra Elaine, 2009

Rizzo, Alexandra Elaine, 2009, A new species of Ephesiopsis (Polychaeta: Sphaerodoridae) from off southeastern Brazil, Zootaxa 2307, pp. 61-67 : 63-67

Ephesiopsis shivae new species

( Figures 1–3 )

Type material: MZSP 883 (holotype), 24 0 07.637'S 45 0 51.895'W, 0 9.01.1998, Sta. 6661, 147 m, Santos/São Paulo to Ilha Grande Bay/Rio de Janeiro, collected with dredge; MZSP 1031 (paratypes, 2), 24 0 07.637'S 45 0 51.895'W, 0 9.01.1998, Sta. 6661, 147 m, Santos/São Paulo to Ilha Grande Bay/Rio de Janeiro, collected with dredge.

Diagnosis: Macrotubercles with distal papillae. Eyes absent. Chaetae simple, and compound falcigers in all chaetigers. First chaetiger with a pair of falcate hooks. Pygidium with four macrotubercles with terminal papillae.

Description: Holotype measuring 20.5 mm long and 0.9 mm wide, with 100 chaetigers; paratypes are 10 and 16 mm long, 0.7 and 0.8 mm wide, and have 49 and 78 chaetigers respectively. All are complete specimens. Two individuals (holotype and one paratype) with inflated body, filled by large eggs with dark nuclei, apparently in final stage of maturation ( Figures 1−2 E). Body long, slender, with minute epidermal papillae ( Figure 2 A). Prostomium indistinctly fused to peristomium; with two pairs of lateral antennae and a median, papilliform antenna. Median antenna slightly shorter and with larger base than lateral antennae. One small papilla located at base of each lateral antenna. A pair of papilliform peristomial cirri located between lateral antennae and first chaetiger. Several papillae present among the antennae ( Figure 2 B). Eyes absent. Mouth ventro-frontal. Proboscis invaginated, long, cylindrical. Macrotubercles arranged in two longitudinal rows; sessile, rounded, each with a terminal papilla ( Figure 2 C). Microtubercles with narrow bases and elongated distal papillae, slightly larger than terminal papillae of macrotubercles ( Figure 2 D); microtubercles visible mainly on anterior region. Parapodia uniramous and poorly developed, consisting of a conical, distally slender acicular lobe with papillate surface that is slightly longer than the macrotubercles. A single aciculum is present, which may project outwards. Ventral cirrus digitiform, irregular ( Figure 3 A–C). Parapodia of posterior chaetigers rudimentary. Parapodia of chaetiger 1 bear a pair of strong recurved hooks, visible only with light microscopy ( Figure 3 D). Following chaetigers supra-acicular with 3-4 simple chaetae and infraacicular with 1-2 compound falcigers. Simple chaetae have a subdistal protuberance and are distally triangular ( Figure 3 E). Compound falcigers short, with a robust shaft that is distally triangular and spinulate; with ligament extending from end of shafts to lateral bases of distal appendages ( Figure 3 F). Chaetae can be absent from some chaetigers, in particular the median ones. Pygidium with four macrotubercles that bear terminal papillae.

Discussion: Three specimens of E. guayanae were recorded (record Ch 35 Dr34) and deposited at the Natural History Museum of Los Angeles County; however, this type material is probably lost (Salazar- Vallejo, Carrera-Parra & Tovar-Hernandes, pers. com.). This species was first described as Sphaerodorum sp. C from off Brazil [sic], by Hartman (1965: 96). Later, the type locality was corrected to off Guyana ( Hartman and Fauchald 1971). The taxon was assigned to the monotypic genus Ephesiopsis Hartman and Fauchald 1971 , to contain species having two rows of macrotubercles with terminal papillae, and hooks on the first chaetiger, in addition to simple and compound chaetae on all chaetigers. Two other genera resembling Ephesiopsis also have a pair of hooks on the first chaetiger, but they have either simple chaetae on all chaetigers ( Sphaerodorum ) or only compound chaetae ( Ephesiella ), never with both types present.

Ephesiopsis shivae sp. nov., differs from Ephesiopsis guayanae in having macrotubercles with slightly smaller terminal papillae. The simple chaetae are not as pointed distally as those illustrated by Hartman and Fauchald (1971: 311). Eyes were not observed. In Ephesiopsis shivae sp. nov., the microtubercles are visible only on the anterior region, but this may result from body modifications because of the number of large eggs inside the body cavity. The posterior region of E. guayanae was not mentioned in the original description, although the holotype is a complete specimen. It is smaller than the specimens of E. shivae sp. nov., being 2.2 mm long and 0.2 mm wide, with 26 chaetigers. Eggs were not observed in the specimens from Guyana. E. shivae sp. nov. also has four macrotubercles with terminal papillae on the pygidium, similar to that of the longitudinal row. Corresponding macrotubercles were not mentioned in the original description of E. guayanae , and it is possible that they are not present in this species.

Distribution: Southwestern Atlantic Ocean, off Brazil (São Paulo State) at 147 m depth.

Etimology: The species is named shivae after Shiva, a Siberian husky belonging to the author.

Figures

FIGURE 1. Ephesiopsis shivae new species – Holotype: A. anterior and median region, laterodorsal view (scale: 0.5 mm).

FIGURE 2. Ephesiopsis shivae new species – Holotype: A. Complete specimen, twisted body; B. Anterior edge in dorsal view; detail of cephalic appendages, hook and first chaetiger; C. Macrotubercle; D. Microtubercle between two macrotubercles; E. Egg from anterior region, near cephalic appendages. (Abbreviations: Pr—prostomium, v—ventral, h—hook, la—lateral antenna, ma—macrotubercle, par 1 — first parapodium, vc—ventral cirrus, tp—terminal papilla).

FIGURE 3. Ephesiopsis shivae new species – Holotype: A. Parapodium 4; B. Parapodium 12; C. Parapodium 23; D. Hook from first chaetiger; E. Simple chaeta; F. Compound falcigerous chaeta. (Abbreviations: pa—papilla, vc—ventral cirrus).