(Pallas, 1766)
Description:
Anterior part of prostomium more or less notched anteriorly, bearing paired lateral antennae and paired palps laterally; posterior part of prostomium rectangular, with a median antenna and four eyes arranged in a rectangle. Antennae and palps awl-shaped, median antenna twice as long as lateral ones. Caruncle covers the anterior 4 chaetigers, with 6-8 lateral folds with or without secondary folds (H. carunculata-head/parapodium). Ventral mouth surrounded by anterior part of prostomium and the first 3-5 chaetigers. Anus dorsal and without papilla.
Gills on all chaetigers, each with two stems and tree-shaped. Dorsal and ventral cirri with basal joint. Capillary notopodial chaetae smooth or harpoon-like, others arrowhead-like. Neuropodial chaetae forked, with very small spur, serrated, others arrowhead-like (H. carunculata-detail).
Size:
Up to 300 mm for 60-150 segments.
Colour:
Yellowish or red-brown ventrally, greenish or brown with green and black transverse bands and white intersegmental bands dorsally; gills red with white spots; caruncle red and white.
Habitat:
Lives on corals, rocks, stones, mud, sand, drifting wood and among Posidonia. Intertidal to subtidal.
Distribution:
A widespread species, mainly in tropical regions and subtropical regions of the Atlantic and the Mediterranean. Only once found on the Dogger Bank, North Sea.