Salvatoria koorineclavata

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Salvatoria koorineclavata is a tiny marine worm in the family Syllidae, part of the segmented worms (Annelida). It is related to an Australian species that has been called Salvatoria clavata; the Australian relative is similar but has some different features, such as a longer pharynx and proventricle and longer, curved chaetae spines. Another similar species in the genus Brania and Salvatoria also exists in other parts of the world.

Key features
- Size and body: Very small, with the holotype measuring about 2 mm in length and 0.27 mm wide, and about 27 body segments (chaetigers). The worm carries bristles (chaetae) along its body.
- Head and sense organs: The prostomium (head) is oval with 4 thick eyes arranged in a trapezoid and 2 eye spots. It has spindle-shaped antennae, with the median antenna longer than the lateral ones. Palps are about the same length as the prostomium and are dorsally fused with a small notch. It has two pairs of ciliated nuchal organs between the prostomium and peristomium.
- External feelers and dorsal organs: Its tentacular cirri and antennae are similar in form but longer, and the dorsal cirri are spindle-shaped on all segments (slightly longer on the first segment).
- Parapodia and chaetae: The anterior parapodia carry about 9–10 compound chaetae, which get shorter toward the back (26 μm above and 12–13 μm below). The number of posterior compound chaetae drops to about 5–6 in the rear segments. Some specimens show simple ventral chaetae on the rear parapodia. In the front part of the body, each parapodium has two aciculae (one straight and one pointed); the midbody also has a solitary acicula.
- Bristles details: The compound chaetae have blades with two points (bidentate) and long, thin spines directed toward the tip, with the spines longer on the topmost chaetae.
- Internal features: The pharynx is long, spanning roughly 4–5 segments. Its small, rhomboid pharyngeal tooth has no papillae at its opening. The proventricle is about the same length as the pharynx and contains 21–22 rows of muscle cells. The pygidium (rear end) is small with two anal cirri, similar to the dorsal cirri but a bit longer. The holotype even shows natatory (swimming) chaetae.

Habitat and distribution
- Salvatoria koorineclavata is found around the Australian continent. The original specimens were collected along the southern coast, from Jervis Bay in New South Wales to Kalbarri in Western Australia. It is common in shallow waters on a variety of substrates, up to depths of about 29 meters.