Hiatella arctica

Taxobox
name = "Hiatella arctica"


image_caption =
status =
regnum = Animalia
phylum = Mollusca
classis = Bivalvia
ordo = Myoida
familia = Hiatellidae
genus = "Hiatella"
species = "H. arctica"
binomial = "Hiatella arctica"
binomial_authority = (Linnaeus, 1767)

"Hiatella arctica" is a marine bivalve mollusc in the family Hiatellidae, found in the Arctic Ocean, and around all three main New Zealand islands and the Chatham Islands, plus Australia's Macquarie Island, from low water to depths of up to 180 m.

The thick shell is attached by thread-like hairs in holes, crevices or algal holdfasts, but often bores into soft rock and shells. The shell's shape is approximately oblong but highly irregular with no two specimens being alike. Two distinct ridges extend posteriorly from the beak on each valve. In juveniles, the ridges possess short spines that are often worn away in older specimens. The shell is sculptured with thick concentric ridges.

This species is a suspension feeder. The type of substratum selected by juveniles determines whether they become burrowers or nestlers. Those settling on hard rock will become nestlers while juveniles settling on soft rock become burrowers. The adults are able to bore into rock by mechanical abrasion using the valves of the shell. The initial penetration of the rock by juveniles may involve chemical as well as mechanical means. Coloration is dull white with a coarse yellow-brown periostracum, with a white interior.

Length is up to about 40 mm.

References

* Powell A. W. B., "New Zealand Mollusca", William Collins Publishers Ltd, Auckland, New Zealand 1979 ISBN 0-00-216906-1
* [http://www.marlin.ac.uk/species/Hiatellaarctica.htm Marlin]