The ability of two bottlenosed dolphins Tursiops truncatus to understand imperative sentences expressed in artificial languages were studied. One dolphin (Phoenix) was tutored in an acoustic language whose words were computer-generated sounds presented through an underwater speaker. The second dolphin (Akeakamai) was tutored in a visually-based language whose words were gestures of a trainer's arms and hands.

Excerpts from Current Biology, Volume 22, Issue 20, R860-R861, 23 October 2012

The whale lived among a group of dolphins and socialized with two female white whales. The whale was exposed to speech not only from humans at the surface -- it was present at times when divers used surface-to-diver communication equipment.

Research has revealed that bull sharks bite with almost 6,000N, a force that is greater than what is required to kill and eat prey. In a study published in the journal Zoology, Maria Habegger from Tampa’s University of South Florida, along with colleagues in the US and Germany, examined bite forces produced by 13 shark species and their close relatives, ranging from 1m-long ratfish to the great white shark.