Megamouth shark used as a means of identifying other individuals of megamouth sharks. Their mouths can reach up to wide. Megamouth sharks have up to 50 rows of teeth in their upper-jaw and up to 75 rows of teeth in their lower-jaw. In 1990, a 4.9-m (16-foot) male megamouth shark was caught near the surface off Dana Point, California. This individual was eventually released with a small radio tag attached to its soft body. The tag relayed depth and time information over a two-day period. During the day, the shark swam at a depth around , but as the sun set, it
Robot fish the speed of swimming will increase. It exhibits a state of shock and confusion to the foreign object much like a real fish would. Robot fish record this type of behavior in advance. Military defense and marine protection are of rising concern in the research field. As missions become more complicated, high-performance Autonomous underwater vehicle (AUVs) become necessary. AUVs require fast propulsion and multidirectional maneuverability. Robotic fish are more competent than current AUVs propelled by motion because the fish is a paradigm of bio-inspired AUV. Like living fish, robot fish can operate in complex environments. They can not only perform