Sockeye salmon natural selection against large bodies. Populations with higher levels of predation tend to evolve smaller body size. Without the threat of predation, salmon that breed early in the season live longer than those that breed late in the season. Other ecological factors like stranding effect select for smaller body size in sockeye salmon when present in a habitat. Stranding is when salmon swim into dry land or shallow water during their migration for spawning and die from suffocation. In fact, studies show that the Sockeye salmon with the largest bodies are most susceptible to stranding mortality. Reproduction is marked by
Robot fish Robot fish A robot fish is a type of bionic robot, which has the shape and locomotion of a living fish. Since the Massachusetts Institute of Technology first published research on them in 1989, there have been more than 400 articles published about robot fish. According to these reports, approximately 40 different types of robot fish have been built, with 30 designs having only the capability to flip and drift in water. Most robot fish are designed to emulate living fish which use Body-caudal fin (BCF) propulsion. BCF robot fish can be divided into three categories: Single Joint (SJ), Multi-Joint