Altamaha Spinymussel
A large freshwater mussel with one to several shell spines survives only in the Altamaha River basin.
Artwork inspired by John Abbot
The shell’s spines are unusual but variable, and juveniles may differ from older animals. Like other mussels, it filters water and depends on host fish to carry larvae through part of the life cycle.
Sedimentation, flow alteration, contaminants, and low recruitment threaten populations. Mussels should never be pried from the riverbed for identification.
- Native basin
- This federally endangered mussel is endemic to Georgia’s Altamaha River basin.
- Shell defense
- variable shell spines
- Larval partner
- host-fish life cycle
Quick guide
- Recognition
- Heavy dark shell bearing variable pointed or knoblike spines.
- Habitat
- Sandbars and mixed sand-gravel runs in the Altamaha and lower tributaries.
Recognize it through habitat and behavior
- Recognition
- Heavy dark shell bearing variable pointed or knoblike spines.
- Habitat
- Sandbars and mixed sand-gravel runs in the Altamaha and lower tributaries.
- Ecology
- Larvae must attach temporarily to suitable host fish before settling.
- Time it
- Present year-round; low clear water may reveal shells, but handling is inappropriate. Watch from legal public access; keep distance and protect habitat.
Good to know
Observe shells only when legally found; never collect or disturb living mussels.
Notice these
- variable shell spines
- Altamaha sandbar
- host-fish life cycle