Syllis cf. schmardiana Haswell, 1886

Martín, Guillermo San, Lucas, Yolanda & Hutchings, Pat, 2024, The genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae: Syllinae) from Australia (Fourth part), Zootaxa 5453 (1), pp. 1-32 : 11-13

Syllis cf. schmardiana Haswell, 1886

Figure 7

Syllis schmardiana Haswell, 1886: 742 , pl. 51, figs 4–8.

Material examined. AUSTRALIA. WESTERN AUSTRALIA: Cape Range National Park, inshore limestone reef off Neds Camp , 21° 59’ S, 113° 55’ E, coll. J. K. Lowry, 2 Jan 1984, frilly Caulerpa , 1 m, G. San Martin id., AM W.54886, 1 specimen .

Description. Single specimen examined broken, regenerating posteriorly, 3 mm long, 0.35 mm wide, and 39 chaetigers in addition to five regenerating segments and other few segments without chaetae and pygidium with two anal cirri. Body without colour markings except for very thin transversal reddish lines on most anterior segments ( Fig. 7A ). Prostomium ovoid, with two pairs of eyes in open trapezoidal arrangement; median antenna lost, lateral antennae short, with 12 articles. Peristomium shorter than subsequent segments; dorsal tentacular cirri longer than antennae, with 15 articles, ventral ones shorter, with 10 articles. Dorsal cirri slender and delicate; most anterior dorsal cirri longer than others, with about 15–11 articles; anterior and midbody dorsal cirri alternating long and short, with 17–8 articles respectively ( Fig. 7A, B ). Parapodia conical, with a distal small lobe. Compound chaetae heterogomph falcigers with short, bidentate blades and very short spines on margin, all similar along body ( Fig. 7C, D ). Anterior parapodia with numerous chaetae, about 12–13, and blades with small dorso-ventral gradation in size, about 18 µm above, 11 µm below ( Fig. 7C ); number of chaetae diminishing posteriorly to eight chaetae per parapodium, blades about 16 µm above, 10 µm below ( Fig. 7D ). Dorsal simple chaetae on posterior parapodia, distally unidentate ( Fig. 7E ). Ventral simple chaetae only seen in most posterior parapodia, apparently smooth, bidentate ( Fig. 7F ). Two aciculae in each anterior parapodia, slender, distally broad ( Fig. 7G ); midbody and posterior parapodia with a single acicula, distally blunt, rounded, somewhat oblique ( Fig. 7H ). Pharynx strongly contracted, extending through seven segments; pharyngeal tooth located on anterior margin. Proventricle long, through eight segments, with about 35 muscle cell rows. Anal cirri with 10 articles.

Remarks. The identification of this single specimen is tentative, since the original description is incomplete, omits several characters and the type is lost. Furthermore, this species has not been recorded since its original description and it is considered by Licher (1999) as synonymous with S. variegata Grube, 1860 . Although it is difficult to characterize S. schmardiana , it seems to be a different species from S. variegata . Our specimen differs in several ways from the Haswell’s description; it is much smaller and the dorsal cirri are much shorter; however, our specimen is a juvenile and the specimen described by Haswell is a pre-epitoke specimen, with notoaciculae, so these differences could be because of the different stage of development, but other details agree, such as the slender dorsal cirri and the compound chaetae. Types seem to be lost.

Habitat. Found in Caulerpa sp.

Distribution. Australia (NSW, WA?)

Figures

FIGURE 7. Syllis cf. schmardiana Haswell, 1886. A, anterior end, dorsal view. B, midbody long and short dorsal cirri. C, compound chaetae, anterior parapodium. D, compound chaetae, posterior parapodium. E, dorsal simple chaeta. F, ventral simple chaeta. G, aciculae, anterior parapodium. H, acicula, posterior parapodium. AM W.54886. Scale. A: 0.2 mm. B: 0.1 mm. C-H: 20 µm.