Description: Members of family Hesionidae have segments at least as wide as they are long, and without dorsal elytra, paleae, or other setae. They have two prostomial anteroventral palps and peristomial tentacular cirri. Enlarged ventral cirri on the first several segments is a synapomorphy for this family. Micropodarke dubia has palps with 2 segments of approximately equal length (photo). Some of its setae are compound. It has 2 (not 3) prostomial antennae (photo) and two pairs of eyes (photo). The pharynx (photo) has no jaws nor teeth. The species has 6 pairs of tentacular cirri, 4 of which are on the peristomium (photo). There are large lobes at the bases of the parapodia. The pygidium has two cirri (photo). This individual is colored creamy white ventrally and has brown speckles dorsally.
How to Distinguish from
cirrata and Podarkeopsis
brevipalpa have 8 pairs of tentacular
pugettensis has 3 prostomial
and one between them and slightly dorsal).
Geographical Range: SE Alaska to central California, + Yellow Sea and Japan in the western Pacific.
Depth Range: Low intertidal to 40 m.
Habitat: Fine sand
this individual crawling through the sediment attached to the rhizome
some subtidal Zostera
eelgrass. The family description on the Tree of Life
says that the few species studied from the family seem to be
However, this species has no jaws nor teeth in its pharynx, and its gut
was stuffed full of sediment when I found it. The sediment
voided over several hours as I studied it.
Kozloff, 1987, 1996
Pleijel, Fredrik and Greg Rouse, 2005. A revision of Micropodarke (Psamathini, Hesionidae, Polychaeta). Journal of Natural History 39:17 pp 1313-1326
General Notes and Observations: Locations, abundances, unusual behaviors:
Although this animal was anesthetized, it never did stop a slight but continual writhing motion, which made it difficult to photograph with the microscope camera (which requires a slow shutter speed).
Authors and Editors of Page:
Dave Cowles (2014): Created original page
CSS coding for page developed by Jonathan Cowles (2007)
Salish Sea Invertebrates web site provided courtesy of Walla