Which of the following organisms is a vertebrate?

Insect Sponge Fish Starfish

Fish

Explanation:

fish are a class of aquatic vertebrates. they are classified as vertebrates due to the presence of a backbone wherein some cartilaginous fish have vertebrae made of cartilage rather than hardened bones. they have gills slits on both sides for exchange of oxygen and CO2. They have fins for balance and to help propel and steer in water. they also exhibit characteristics peculiar to vertebrates.

Fish

Explanation:

Fish is an example of vetebrates. Veterbrates are animals that have backbone. Fish have gills which is use for respiration. They have streamlined body which help them to adapt to swimming in water. They constitute the non tetrapods vetebrates i.e they don't have four limbs. The have pair of find and unpaired which help them to move in water.

so whats the answer