Can Ghost Crabs Make Sounds? How Do They Do It?
Researchers indicate that ghost crabs are the first animals to use the sounds produced by their stomachs for communication.
Crabs are known for their “fiery temper,” and most crab species produce sounds that we often hear, such as the clattering noise from their pincers. However, ghost crabs have an additional secret weapon to threaten enemies and scare off predators while their large pincers are busy fighting. Additionally, they can create sounds by rubbing the ridges on their pincers to intimidate foes.
Ghost Crab. (Photo: Wikiwand)
Jennifer Taylor, a biologist studying crabs at the Scripps Institution of Oceanography in La Jolla, California, stated: “This is definitely an advantage if there are enemies nearby. They can raise their pincers and be ready to charge, but at the same time, they can still produce these sounds from their stomachs.”
Ghost crabs possess an unusual stomach that helps them process food. Inside their stomachs are small teeth arranged next to each other, forming a “gastric mill.” In the case of ghost crabs, the mill includes an additional sharp tooth in the center. When food enters the stomach, the mechanism of the gastric mill is responsible for chopping and grinding whatever goes inside.
According to The Guardian, biologist Taylor mentioned that she felt drawn to the sounds made by this crab species. “I observed them to see if they were moving anything other than their claws, and at first glance, nothing seemed to be happening. Moreover, the researcher believes that this crab species is very intelligent.”
They not only developed special mechanisms in their pincers to create sounds, but they also employ this second method as a backup. If their pincers are busy, they can produce similar sounds from within their stomachs.
Thus, researchers attempted to delve deeper into the internal structure. The first trial failed when a crab crushed the tiny endoscope inserted into its mouth. In the second trial, they approached the task more effectively.
Using a technique called doppler laser vibrometry, scientists directed a laser beam at various parts of a crab. The results indicated that the strongest vibrations came from the abdomen of this creature.
Strange sounds produced by ghost crabs are generated by teeth in their stomachs.
To further investigate this mechanism, Taylor’s research team brought crabs to a medical center. They X-rayed the crabs while they struggled with sticks and other objects. After several attempts, researchers recorded footage of the gastric mills in action, creating warning sounds.
Ghost crabs are the size of a hand, living in burrows dug in the sand and are primarily nocturnal. This crab species is known in Vietnam as “white-clawed crab.” While edible, their meat is not as plentiful or delicious as that of other crab species. If one wishes to eat them, the preparation method for white-clawed crabs is similar to that of other crabs, requiring high temperatures and prolonged cooking to completely eliminate any parasites present in these crabs.
