Aphrodita japonica Marenzeller, 1879

Common name(s): Sea mouse

Phylum Annelida
Class Poluchaeta
Subclass Palpata
Order Aciculata
Suborder Phyllodocida
Superfamily Aphroditacea
Family Aphroditidae
Aphrodita japonica captured at 70 m depth west of Yellow Island, WA from a soft bottom.
(Photo by: Dave Cowles, July 2007)
Description:  Members of Family Aphroditidae have a wide, flat dorsal surface nearly or completely covered with a tangle of elongated notosetae which are so long and narrow that they look like a feltlike tangle of coarse, dark hairs.  The notosetae are covering flattened plates (elytra) but these cannot usually be seen.   Their body segments are wider than long and this, combined with the feltlike tangle of notosetae, make the animals look like a dead mouse when viewed from above.  Aphrodite japonica has elytra completely hidden by the notosetae, which are smooth and do not have barbs near their tips.  The palps are only 4-7x as long as the prostomium and the median antenna is at least as long as the prostomium.  The body has between 38-43 segments.  The neurosetae sometimes have hairs or short spines, and the most ventral neurosetae are coppery or gold in color.

How to Distinguish from Similar Species: Laetmonice pellucida has elytra not completely covered by notosetae. Aphrodita longipalpa has palps 8-11x as long as the prostomium.  Aphrodita parva has a body of only about 27 segments.  Aphrodita negligens has a club-shaped median antenna which is shorter than the prostomium. Aphrodita refulgida has smooth neurosetae and its ventralmost neurosetae are bright green and iridescent.

Geographical Range:  Reports include records from British Columbia through coastal Washington and California to Costa Rica, and our marine station has several specimens collected in the area around Rosario and the San Juan Islands.  Presumably they may also be found in Japan.

Depth Range:  Subtidal to at least 90 m

Habitat:  Buried in mud and sand.

Biology/Natural History:  This is one of the few marine species (along with sea cucumbers) that appears to use anal respiration.



Dichotomous Keys:
  Flora and Fairbanks 1966
  Kozloff 1987, 1996

General References:

Scientific Articles:

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:

The segments visible on the underside show clearly that the animal is a polychaete.  The head is to the left.  Notice also the thicker, darker neurosetae which contrast with the tangle of thinner, lighter notosetae.

Here is a ventral view of the head with the palps showing.  The prostomium cannot be seen under the tangle of notosetae.

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Dorsal view of notosetae, with some neurosetae visible below.  Notice the tangle of long, thin notosetae.  The animal crawls through the mud, some of which adheres to the notosetae.  A millimeter scale is visible to the right. Ventral view of neurosetae, with some notosetae visible behind.  Notice how much thicker and stiffer the neurosetae are than the notosetae, and also that the ventralmost neurosetae are a dark coppery color.

Aphrodita japonica appears to use some sort of anal respiration.  Every 10-15 seconds a dorsal projection at the posterior end opens up and a stream of water spurts forcefully out.  The projection is nearly 1 cm tall and wide.  The stream of water causes a visible jet at the water's surface at least 10 cm away.  This photo shows the animal in mid-spurt.

Authors and Editors of Page:
Dave Cowles (2007):  Created original page
Jonathan Cowles (2007):  Updated page with CSS