Rays

internal structure of cartilaginous fish

internal structure of cartilaginous fish

Cartilaginous fish such as sharks, skates, and rays are vertebrates whose internal skeleton is made entirely of cartilage and contains no ossified bone. ... The skin of rays is naked in places, that is, without dermal teeth, but on the back of or upper tail surface, the dermal teeth have developed large, strong spines.

Venus Difference Between Earth and Venus
Difference Between Earth and Venus
Venus is often named as Earth's twin because both worlds share a similar size, surface composition and have an atmosphere with a complex weather syste...
Static Difference Between Dynamic and Static IP
Difference Between Dynamic and Static IP
What is the difference between a dynamic and static IP address? When a device is assigned a static IP address, the address does not change. Most devic...
Dating Difference Between Dating and Relationships
Difference Between Dating and Relationships
The main difference between dating and being in a relationship is that people in a relationship connect by a mutual commitment to each other. How you ...