Alosa to detect ultrasound (at frequencies above 20 kHz, which is the limit of human hearing). This was first discovered by fisheries biologists studying a type of shad known as blueback herring, and was later verified in laboratory studies of hearing in American shad. This ability is thought to help them avoid dolphins that find prey using echolocation. "Alosa" species are generally pelagic. They are mostly anadromous or semianadromous with the exception of strictly freshwater landlocked species. "Alosa" species are generally migratory and schooling fish. Males usually mature about a year before females; they spawn in the late spring to summer.
Chaca (genus) Chaca (genus) Chaca is the only genus in the catfish family Chacidae. These fish are commonly known as squarehead catfishes, frogmouth catfishes, or angler catfishes. These unusual fish have a sedentary lifestyle and spend much of their time motionless. The name "Chaca" is because, when removed from the water, they will rapidly repeat the sound "chaca". Only "C. chaca" makes these sounds; the other species do not. The four currently recognized species in this genus are: "Chaca" species are found in fresh water from eastern India to Borneo. "C. chaca" is found in rivers, canals, and ponds of grassland, scrubland,