Erinaceusyllis, Guillermo San Martin, 2005

Guillermo San Martin, 2005, Exogoninae (Polychaeta: Syllidae) from Australia With the Description of a New Genus and Twenty-two New Species, Records of the Australian Museum 57, pp. 39-152 : 73-75

Genus Erinaceusyllis n.gen.

Diagnosis. Body small to minute, more or less densely covered by papillae, usually small, short, scarce, sometimes also distributed on cirri and parapodia. Prostomium with 3 antennae, 4 eyes and 2 anterior eyespots. Peristomium usually large, covering posterior margin of prostomium, sometimes forming 2 dorsolateral wings covering nuchal organs; single pair of tentacular cirri. Dorsal cirri on chaetiger 2 absent or present, depending upon the species, usually absent. Antennae, tentacular cirri and dorsal cirri spindle-shaped to pyriform, with slightly bulbous bases and short to moderately long tip. A pair of anal cirri similar to dorsal cirri, usually longer. Compound chaetae heterogomph, with blades short or long, sometimes long and slender, bidentate, bidentate and unidentate, or unidentate. Pharyngeal tooth small, conical to rhomboidal, located near anterior margin, sometimes near middle of pharynx; pharynx usually without papillae around opening, but present on larger species. Proventricle long and wide, barrelshaped, with numerous, slender muscle cell rows (15–22). Mature males with natatory chaetae; females brooding eggs dorsally, by means of capillary notochaetae.

Type species. Sphaerosyllis erinaceus Claparède, 1863 , herein designated.

Remarks. This new genus consists of several species previously described under Sphaerosyllis and several described as sub-species of Sphaerosyllis erinaceus , differing by the compound chaetae; these differences are sufficient to consider all of them as different species. Erinaceusyllis n.gen. is obviously similar to Sphaerosyllis .

Species of Sphaerosyllis , however, always have papillae on the pharynx opening, the pharyngeal tooth is conical, always located on the anterior margin of pharynx or very near, usually with a short proventricle provided with few, a large muscle cell rows, large posterior acicula distally bent at a right angle, blades of compound chaetae always short and unidentate, and brood developing ventrally embryos and juveniles, without capillary notochaetae on the females, only on males. Sphaerosyllis horrockensis , Sphaerosyllis belizensis , and S. centroamericana , are herein transferred to Erinaceusyllis n.gen. because their characters agree with the diagnosis given above and they are different to that of Sphaerosyllis as given below. Prosphaerosyllis is close to Erinaceusyllis n.gen., but the pharyngeal tooth is rhomboidal to oval and located usually near middle of pharynx, antennae are always short, tentacular and dorsal cirri have a bulbous cirrophore and retractile cirrostyle, and the papillae are more numerous, usually of different sizes.

The genus Cicese Díaz-Castañeda & San Martín, 2001 is identical to Erinaceusyllis but has two pairs of tentacular cirri instead of a single pair (Díaz-Castañeda & San Martín, 2001).

The type species of this genus is Sphaerosyllis erinaceus Claparède, 1863 ; the original description, however, is incomplete (Claparède, 1863); the species has been reported worldwide but probably these records represent a complex of different species, that need to be re-examined.

Key to species of Erinaceusyllis recorded from Australia

1 Dorsal cirri present on chaetiger 2 .......................................................................... E. horrockensis

—— Dorsal cirri absent on chaetiger 2 .................................................................................................. 2

2 Blades of compound chaetae all bidentate .................................................................. E. bidentata

—— All or some blades unidentate ........................................................................................................ 3

3 Longer blades of compound chaetae bidentate, remaining blades unidentate .................................................................................................................... E. belizensis

—— All blades unidentate ...................................................................................................................... 4

4 At least some compound chaetae with long, slender blades ......................................................... 5

—— All blades relatively short, falcate ................................................................................................. 7

5 Median antenna located close to lateral antennae, on anterior margin of prostomium, similar in size to lateral ones. Anterior eyes in line with eyespots ................................................................................ E. centroamericana

—— Median antenna longer than lateral ones, inserted posteriorly. Anterior eyes near posterior ones, posterior to eyespots ............................................................... 6

6 Long and mid-sized blades of each parapodium provided basally with long, erect pointed spines ............................................................................. E. serratosetosa

—— Long and mid-sized blades with short, fine marginal spines. Blades slender, sabre-shaped ........................................................................................... E. ettiennei n.sp.

7 Dorsal cirri each provided with 1–2 distinct, long, mushroomshaped papillae .............................................................................................. E. cirripapillata n.sp.

—— Dorsal cirri without this kind of papillae ....................................................................................... 8

8 Pharyngeal tooth located in front of middle of pharynx .................................... E. opisthodentata

—— Pharyngeal tooth located near anterior rim ................................................................................... 9

9 Blades of compound chaetae of each parapodium all similar in size, those of dorsal chaetae with long marginal spines and remaining smooth or with short marginal spines ........................... E. hartmannschroederae n.sp.

—— Compound chaetae with dorsoventral gradation in length of blades, all of which are provided with short marginal spines ....................................... E. kathrynae n.sp.