Subfamily

Anoplosyllinae

Syllinae is one of the most diverse subfamilies of Syllidae (16 genera and more than 200 species), so it is not surprising that it presents a wide variety of morphologies.

DIAGNOSIS

Syllides convolutus has a strong body, thickened in the area of the prostomium, which is rectangular in shape (Fig. 1A). It has 4 large eyes arranged in a trapezoid. The species is described with some prominent and long palps (longer than the prostomium), but those of the illustrated specimen were directed towards the ventral zone and were hardly appreciable. Its appendages are long and smooth in the anterior area of the body, and segmented towards the back. Its aciculae have a rounded or truncated tip (Figs. 1B, 1C). It has compound chaetae with long and short blades (Figs. 1D, 1E, 1F), bidentate with both teeth of similar length and medium-sized spines.

Figure 1. Syllides convolutus: A) Dorsal anterior view; B), C) Aciculae; D) Compound chaetae with long blades; E), F) Compound chaetae with short blades. Scales: A, 0.18 mm. B–E, 20 µm. Original work

VARIABILITY

The bodies are small but vary in thickness. There are species with all smooth appendages. The compound chaetae are usually bidentate and thick, also spinigerous in some cases, with short or medium spines. The acicuale vary the morphology of the tip, being able to be curved, rounded or truncated. To access more figures on these morphologies, review other subfamilies.