Life habit and ontogeny of the unusual arcid bivalve Ambrogia mytiloides (Brocchi, 1814)
Version of Record online: 12 MAR 2007
Volume 39, Issue 3, pages 245–252, September 2006
How to Cite
Perna, R. L. (2006), Life habit and ontogeny of the unusual arcid bivalve Ambrogia mytiloides (Brocchi, 1814). Lethaia, 39: 245–252. doi: 10.1080/00241160600799937
- Issue online: 12 MAR 2007
- Version of Record online: 12 MAR 2007
- received 18th February 2005, revised 2nd May 2006.
- functional morphology;
The unusual Plio-Pleistocene arcid Ambrogia mytiloides (Brocchi, 1814) has a large, elongate, smooth and streamlined shell. On the basis of these characters and the occurrence of moderate shell torsion, the mode of life of this species was formerly thought to be semi-infaunal endobyssate, obliquely oriented like the twisted arcid Trisidos. The discovery of shells in life position suggests that this species lived in a subvertical position. Rather than a recliner, this arcid was then a sticker, whose stability was provided by the byssus, which also was used to aid the bivalve in burrowing, and by its large size. The morphology of juvenile valves, smaller than 4 mm, suggests an epibyssate mode of life in its early growth stages. Ambrogia represents a remarkable pathway in the secondary return of arcids to soft bottoms: with this genus, they reached their deepest burrowing level. However, this strategy was not very successful, probably because of evolutionary constraints on the Arcoida.