The rock monster
And she waits.
She moves a bit and then waits.
Blind and hoping.
Bump.
Another bump.
Grab, and she’s got it!
She clamps down on his head good and tight.
Her young fly.
She releases and her unsuspecting victim swims away.
And she waits.
The snuffbox mussel is inconspicuous, yet in many ways is a lie-in-wait predator. But instead of eating her prey, she uses the unsuspecting victim as host to her young. Mussels have a fascinating life history. Mussel babies, called glochidia, need to attach to the gills or fins of a specific type of fish to complete their life cycle. Snuffbox moms with babies sit in the bottom of a stream with their shells open somewhat to display their mantle (their fleshy body inside the shell). A fish swimming by will see that nice, soft flesh and think it’s a free meal. The fish will swim down and try to take a bite of the mussel’s mantle. Once the snuffbox feels the fish poke it, it grabs on to the fish’s head – for the snuffbox the particular fish host is a logperch. Mussels don’t have eyes, so it is purely by feel that the mussel grabs the fish. The mom snuffbox then shoots her microscopic glochidia at the fish’s head so that her young can attach to its gills. The glochidia mature within a few weeks and then drop off the host fish and live out the rest of their life on the stream bottom among the rocks. The glochidia don’t hurt the fish, and the process provides a great way for mussels to move away from their parents – it’s a free ride out of town.
To watch this very cool behavior in action and other cool videos, check out: http://unionid.missouristate.
The snuffbox (Epioblasma trquetra) is a remarkable mussel that is in danger of becoming extinct. Unfortunately there are many threats to this species. Dams affect their ability to move both upstream and downstream, which can isolate populations. Mussels live most of their lives in a very small area, so toxins and poor water quality can easily harm them. Invasive species have also played a role in the decline of snuffbox. Zebra mussels often use any hard surface to attach to, including native mussels like the snuffbox, which end up suffocating because they can’t open their shells. Read more
Lake sturgeon, the only sturgeon species common to the Great Lakes basin, are the largest freshwater fish native to that system. Lake sturgeon can be considered a near-shore, warm-water species preferring water temperatures in the range of mid-50 to low-70 degrees Fahrenheit and depths 15 to 30 feet (although sturgeon in the Great Lakes are often found at greater depths). Lake sturgeon are benthivores, which means they feed on small invertebrates such as insect larvae, crayfish, snails, clams and leeches they find along the bottom of lakes and rivers. 
