Fish form and function: Eye Features Eye Diagramįig. This gives them a larger field of view for avoiding predators. Prey fish, on the other hand, often have eyes on the sides of their bodies. For example, fish predators often have eyes facing forward in order to provide better depth perception. Just like the mouth of a fish, the size, shape, and position of the eyes can provide information about where a fish lives and what it feeds on. The tapetum lucidum is what makes the eyes of sharks and deep sea fish, as well as land mammals like cats and cows, shine at night.įish eyes are usually placed just dorsal of and above the mouth. The tapetum lucidum is a shiny, reflective structure that reflects light and helps vision in low light situations. UV vision helps fishes in foraging, communication, and mate selection.Įlasmobranchs, and some teleosts, also have a tapetum lucidum. UV vision is especially useful for reef fishes. Some fishes can also see in ultraviolet (UV) light. Some elasmobranchs, and most teleost fishes, have color vision. Because fish have no eyelids, their eyes are always open. When light shines on the nerves of the retina, the optic nerves send impulses to the optic lobes. The retina is a light-sensitive membrane rich in nerves that connect to the optic lobes of the brain by optic nerves. Fish form and function: Mouth Features Mouth Diagram (B) An upward facing mouth shows the surface feeding adaptation of the arowana. (A) A bottom facing mouth indicates bottom feeding preferences in the sturgeon.
This sliding action of the mouth can help the fish create a vacuum and quickly suck in a big mouthful of water, which hopefully also includes prey!įig. When a fish has its mouth open, the front lip may slide down and out from the mouth. A fish with a mouth oriented upward usually feeds in the water column, or even above the water (Fig. The size, shape, and placement of the mouth, combined with the type of teeth, provide critical information about the feeding habits of a fish (Table 4.11).įor example, a fish with a mouth on the bottom of its head often feeds by digging in the bottom sediment (Fig. The mouth can reveal a lot about the fish’s feeding habits (Table 4.10). The mouth is at the front, or anterior end, of the fish. Image from Living Ocean, CRDG, University of Hawaii at Manoa
0 kommentar(er)
