probable egg mass
Atys kuhnsi Pilsbry, 1917
|Maximum size: 30 mm
(extrapolated from shell length).
has a thin, strongly inflated shell with a thin, brown
periostracum. The periostracum is uniform and faint while young but
develops dark axial streaks as the animal approaches maturity. The
shell is widest at the midline. Very young shells (1-2 mm) have wavy
spiral striae over the entire shell. During growth, the wavy striae are
replaced by crisp striae on the apex and base which gradually "expand"
to cover the entire shell when fully mature. The animal is cream
frosted with brown and white flecks and with large pink patches that
show through the shell when young. Young animals can be distinguished
semistriata by the profile of the shell, the larger eye spots and
the larger pink spots showing through the shell.
Atys kuhnsi is a
moderately common species that can be found in Halimeda kanaloana beds or mixed
habitats at depths
of 5-15 m (16-50 ft). Dredged shells at
the Bishop Museum extend the depth range to at least 82 m (269 ft).
It is nocturnal in habit and buries itself in the sand during the day.
Spherical, sand-anchored, white egg masses seen in the field in Halimeda kanaoalana beds (much
larger than those laid by Aliculastrum
debilis) are probably laid by this species but that has yet to
be confirmed with captive animals.
Maui, Oahu, French Frigate Shoals and Midway: may be more widely
distributed in the Indo-Pacific if animals currently considered
juvenile Atys naucum from
elsewhere are actually this species.
is often treated as a synonym of Atys
naucum (Linnaeus, 1758) and is listed as A. naucum in Severns, 2011.
However, the Hawaiian animals lack the white and black marginal bands on the parapodia found
in mature specimens of that species. It also appears likely that axially
streaked shells from elsewhere in the Indo-Pacific will turn
out to be this species rather than juveniles of the banded animals illustrated as mature A. naucum in various sources. It was first reported
from Hawaii in Pilsbry, 1917. The photo labelled Atys semistriata in Kay & Schoenberg-Dole, 1991 is probably this species, instead.
Wahikuli Park, Maui; Oct. 25, 1995.
Observations and comments:
1: ( )