It is as primitive as a cave man.
Agnatha is a superclass of fish that are characterised by their lack of a jaw as opposed to the presence of a jaw found in most modern fish. The surviving two classes are hagfish and lampreys.
Primitive fish are typically simpler in structure and behavior, with characteristics like cartilaginous skeletons and lack of jaws. In contrast, more advanced fish have evolved adaptations like bony skeletons, jaws, and specialized sensory organs for improved survival and reproduction. They also exhibit more complex behaviors and reproductive strategies compared to primitive fish.
If you are doing the cross word, the answer is Sturgeon - one of the oldest bony fish linking to fossils of primitive type. ;-)
No a hydra is not a fish. A fish is a vertebrate. A hydra is much more primitive.
No a hydra is not a fish. A fish is a vertebrate. A hydra is much more primitive.
A: jawless fish
All primitive soft-bodied animals that live in the sea. Most fish, most arthropods and quite a few insects.
Most fish have only two heart chambers.Amphibians and some types of primitive fish have four heart chambers, and the fourth one of these is known as the conus arteriosus.
most primitive
No, it is a shark, which are primitive fishes.
Neither. Sharks are primitive fish, with cartiledge skeletons.