Many bivalves can hear! Pearl oysters, for example, are sensitive to sounds between 10 and 1000 Hz, with the low end unfortunately aligning well with the sounds of ship engine noise, drilling and other noise pollution. Researchers found a group of oysters subjected to such noise abandoned their usual behavior of bunching together (common in many bivalves) and closed their valves more frequently and more tightly. Other studies showed this reduced bivalves' ability to feed and grow! #clamFacts
Bivalves lack a central nervous system, but they have complex behaviors, because they live in dynamic environments. Scallops, for example, have eyes, which they use to navigate when swimming, identify predators, and make sense of their environment. Researchers found that presenting stimuli to scallops, they reached out to objects they saw to make sense of them with their feeling tentacles. #clamFactshttps://royalsocietypublishing.org/doi/10.1098/rspb.2021.1730
Shipworms are cellulose-eating bivalves famous for boring into wood, leading to their nickname "the clams that sunk a thousand ships". TIL they also loved to eat early trans-oceanic cables, which were often wrapped in hemp, tree rubber or other plant-based materials. The problem was only solved when a protective metal tape was developed! #clamFactshttps://atlantic-cable.com/Article/Clifford/teredo.htm
Some of the weirdest clams to have ever lived: Shikamaia, extinct giant bivalves over a meter long, shaped like a cross between a surfboard and a giant slipper. They lived during the Permian, over 260 million years ago. It has been hypothesized that they rafted on the bottom of shallow, stagnant lagoons, partnering with photosynthetic algae to harvest sunlight for food, like living solar panels. #clamFacts
Much as carnivory in plants has evolved to help them live in nutrient-starved environments, carnivorous clams have evolved to suck up much larger prey than their filter-feeding ancestors could deal with, allowing them to live in deep, food-scarce environments. The tiny Trigonulina ornata lives off the Brazilian coast from depths from 20-850m and specializes in vacuuming up crustaceans called ostracods. It even sticks debris to its shell to camouflage itself, like a hunting blind! #clamFacts