Pygmy sperm whale significant concentration of magnetite crystals, which suggests that "K. breviceps" can navigate by magnetoreception. Studies have also shown that compared to the sperm whale, the pygmy sperm whale brain has significantly fewer neurons, which may be connected to a decreased complexity in social interaction and group-based living. Like all toothed whales, the pygmy sperm whale hunts prey by echolocation. Sound produced for echolocation by many odontocetes come in the form of high frequency clicks. The frequencies it uses are mostly ultrasonic, peaking around 125 kHz. The clicks from their echolocation has been recorded to last an average of 600 microseconds.
Whale shark Whale shark The whale shark ("Rhincodon typus") is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of and a weight of about . The whale shark holds many records for size in the animal kingdom, most notably being by far the largest living nonmammalian vertebrate. It is the sole member of the genus Rhincodon and the only extant member of the family Rhincodontidae which belongs to the subclass Elasmobranchii in the class Chondrichthyes. Before 1984 it was classified as "Rhiniodon" into Rhinodontidae. The whale shark is found in open