People aren’t the only ones who raise their voices at each other; fish can shout, too. After catching some blacktail shiners—little minnows characterized by a big black splotch on their tail fin—fishery biologists placed them in tanks equipped with underwater speakers to see if noisy conditions affect communication.
While females of Cyprinella venusta (pictured) don’t make noise, males produce two types of sound: growls and knocks. The growl is similar to a cat’s purr and is made when courting a female, while the knocks are more like popping sounds, typically made when males are fighting or defending their nests …read more
Source: Huffington Post Green