The hagfish may also sneeze to clear its nostrils of slime. The hagfish is almost completely blind, but it has a good sense of touch and smell. It has a ring of tentacles around its mouth that it uses to feel for food. It has a tongue-like projection that comes out of its jawless mouth. At the end of the projection are tooth-like rasps that close when the "tongue" is pulled back into the hagfish's mouth.
The hagfish eats marine worms and other invertebrates. It has a very low metabolism and can go for as long as seven months without eating. Newly hatched hagfish are miniature copies of the adult hagfish. The hagfish is found in cold ocean waters in the Northern and Southern Hemispheres.
It is found on muddy sea floors and may live in very large groups of up to 15, individuals. There are about 60 species of hagfish. Agnatha Photo Gallery. Brook Lamprey - Lampetra planeri The brook lamprey is found in small brooks, streams, lakes, and rivers across Europe.
Northern Brook Lamprey - Ichthyomyzon fossor Northern brook lamprey are found in many areas of the midwestern and northeastern United States. Pacific Hagfish - Eptatretus stoutii The Pacific hagfish is also known as the slime eel.
Pacific Hagfish - Eptatretus stoutii The hagfish can tie itself into a knot. Pacific Hagfish - Eptatretus stoutii Hagfish eat worms and invertebrates, but they also enter both dying and dead fish and eat them from the inside out. The fish belonging to this group have no jaws. Their mouths are like holes in their heads that lack movable parts. This group is the earliest to appear in the fossil record. Examples within the fossil record date back to million years ago, in the late Cambrian period, and were most common million to million years ago during the late Silurian and Devonian periods.
Members of this group were generally small and heavily armored and lacked paired fins. They moved along the bottom of the sea where they preyed upon a variety of arthropods. Their gills were quite large and served as food filters and as a respiratory organ. The only surviving agnaths today are lampreys class Cephalaspidiformes and hagfishes class Myxini.
Lampreys and hagfishes are slimy; they completely lack scales or armor and are long and eel-like. The living representatives of this group survive as parasites and scavengers on other fish.
The sharks, rays, and chimaeras make up the second group of fish, the Class Chondrichthyes. Sharks are one of the earliest known jawed fishes. They have an upper and lower jaw made of cartilage.
You and I have two sets of teeth while a shark has an unlimited supply of teeth. Sharks have an unlimited supply of teeth because damaged or lost teeth are continually being replaced with new teeth. Mating in sharks takes place by internal fertilization. The skeletons of sharks and other Chondrichthyans are made of cartilage, unlike human skeletons which are made of bone. They are also probably the earliest vertebrates and have ectoderm. Agnatha is a superclass of the phylum Chordata.
It contains the jawless fish. Two common examples of this would be the lamprey and the hagfish. Agnatha, which is a parphyletic superclass of jawless fish in the phylum chordata, have no actual existing stomach of any such. But they do have a tail and a caudil fin. They eat by sucking its prey.
Class Agnatha. Agnatha means 'no jaws', and they really don't have jaws, although they do have teeth. They also have no stomach, and no boney skeleton. Their skeleton is cartilagineous, like the elasmobranchs. They eat Mikey Phelps. Log in. Animal Life. Study now. See Answer. Best Answer. Study guides. Where are in the animal nutrition in M P. Genetics 20 cards.
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