Megamouth shark to be the sole extant species in the distinct family Megachasmidae, though suggestion has been made that it may belong in the family Cetorhinidae, of which the basking shark is currently the sole extant member. Researchers have predicted the feeding patterns of megamouth sharks in relation to the other two planktivorous sharks; the three plankivourous sharks have ram feeding in common, as it evolved from ram feeding swimming-type ancestors that developed their filtering mechanism to capture small prey like plankton. In addition to the living "M. pelagios", however, two extinct megamouth species – the Priabonian "M. alisonae" and the Oligocene–Miocene
Fish species of Aravaipa Canyon itself. Various methods are used to survey the type and abundance of fish species present at each location. The most common of these is seining, a method that involves dragging a long net through the water and catching many fish at a time. This is best done by two individuals (one on either side of the net) who run downstream, scooping up the fish that are attempting to swim upstream against the current. Another form of seining involves the same two people on either side of the net, but this time they plant the edges of the net into the