Archerd Shell Collection > Shell Classes > Bivalvia > Donacidae

Family: Donacidae (Donax, Coquina Clams)

This is an prolific filter feeder, that provides an important link in coastal food chains, including sea birds and people. It is an indicator species for the status of sandy beach-ocean front habitats. As such, the clam's population is drastically reduced by dam building, dredging, erosion control, and conventional beach remediation practices.

The clam is a nimble surf-rider, with the capability of using its foot to leap out of the sand and ride an in-bound wave using its foot and extended syphons much like a "sail" (Marchant, 2000).

From an evolutionary perspective, Donax serra serra (Roding, 1798) may be quite notable. It shows phenoplasticity for shape; i.e., a heritable switch capability depending on particular environmental cues (Soares et al., 1998). Phenoplastic switching may also underlie the numerous colormorphs of this clam species, such as shown at the right for Donax serra aurantiaca (Krauss. 1848). See comparison of these two species in Figure 1 of Species & Speciation. Phenoplasticity is actually a widespread phenomenon generally overlooked by those schooled in neo-Darwinian survival explanations.


Class: Bivalvia
Subclass: Heterodonta
Order: Veneroida
Superfamily: Tellinacea
Family: Donacidae
Major Genera
  • Genus: Donax
  • Genus: Hecuba
  • Genus: Hemidonax
  • Genus: Iphigenia
  • Genus: Plebidonax

Donax serra aurantiaca (Krauss, 1848)
Saw Donax, a subspecies



Donax variabilis
Coquina Clam

Archerd Shell Collection > Shell Classes > Bivalves > Donax Clams