Fish & Water - Sounds Wild
Scallops

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Scallops

The murky green undersea light reveals a platter-sized sea star inching across the sandy seafloor. It's approaching a scallop partially buried in sand, the two saucer-sized halves of its shell open as it filter feeds. The sea star reaches an arm toward the scallop, which suddenly leaps from the bottom, flapping wildly. This swimming is an awkward fluttering, but it carries this remarkable bivalve to safety.

Scallops are related to clams and mussels, but unlike those sessile mollusks that live buried or fastened to a substrate, scallops can swim by rapidly flapping the two halves of their shell. Their large adductor muscle, the hinge muscle, enables that swimming. That muscle is what we think of as a "scallop" in our dinner, although it is only about ten percent of the animal.

Scallops can also see, another unusual talent for a bivalve. A scallop has about 200 eyes, lining the top and bottom inner edges of the shell. They're usually described as primitive photorecepters, but scientists are re-thinking that. They've looked at the eyeballs themselves and it turns out they are more complicated than was previously thought. They might be seeing better than just shadows or contrast. Scallops have been around hundreds of millions of years, and their unusual abilities have certainly contributed.