Comprehensive DescriptionRead full entry
"Therochaetella chilensis, new species
(Plate 37, Fig. D)
Records: 1.3 sta. 753 (2, TYPE); 1.4 sta. 752 (2).
Description: The body is long, tapering posteriorly, and sand-encrusted. It measures to 25 mm long and has nearly 100 segments. The cephalic cage is formed of the setae of the first two setigerous segments; the longest setae are about a third as long as the body; those of the third segment are about half as long as those in the second and directed obliquely forward; farther back they are directed laterally. All setae in both rami of the first 24 segments are long, distally pointed and transversely barred; neurosetae are somewhat shorter than notosetae. Thereafter neuropodia have thicker, fewer falcigers in which the distal end is bifid ( Fig. D) ; they number about five in a fascicle, with the largest one superior and gradually smaller ones inferior. The corresponding notosetae number eight to ten in a fascicle. In the posterior fourth of the body, parapodia diminish in size, setae decrease in number and the surface is less papillated.
The dissected oral region discloses the presence of a long, black oral tube, neatly crenulated at its anterior margin, much like that in Therochaeta collariferaera (Ehlers) (Hartman, 1965, pl. 40) ; the free margin is closely crenulated. The small prostomium is surmounted by many slender, filiform branchiae, and the paired palpi are large and grooved. When the epithelium is peeled away from the anterior ventrum, it is seen as a smooth, dark surface with a pair of long papillae on each segment behind the second; they are similar to those shown for Buskiella borealis Hartman (1965, pl. 36, Fig. A). This species shares some of the characters of both Therochaeta Chamberlin and Buskiella McIntosh ; both are monotypic genera.
Distribution: Off Santiago, Chile, in 192-209 m."