Fish

When talking about marine life, one word is almost always part of the conversation: fish. Fish are some of the most diverse and expansive species in the entire world. There are about 34,000 species of vertebrate fish (fish with a spine) throughout the water bodies of the Earth. Most fish share certain common features like gills, a notochord (which is like a rod that supports the skeleton), and a tail. The most different and varied fish, from clown fish to eels, and from lampreys to sharks will all share these defining characteristics. Within the species of fish, there are different classifications that have more similarities than differences. One class is the Chondrichthyes, which are fish composed entirely of cartilage. Belonging to this class are some of the worlds most recognizable fishes including sharks and rays.

All sharks are carnivorous, meaning their diet consists of meat, whether it be smaller fish or even other sharks. The feeding habits of sharks largely depends on their habitat, so different sharks will have different diets based on what is available in their area. Tiger Sharks, or Galeocerdo cuvier will feed on any type of meat: other sharks, birds, crabs, and even dead land animals that end up in the ocean. On the contrary, bottom-dwelling sharks have a limited diet, feeding mainly on crabs, other crustaceans, and small fish.

Fish are distributed throughout bodies of water across the entire globe. Natural bodies of water, excluding hot springs and heavily salted lakes like the Dead Sea or the Great Salt Lake will almost always give life to some class of fish. Fish are egg-laying creatures, and have behavior specialized to maximize success in feeding, reproducing, and escaping from enemies. Swimming in schools is one of the behaviors used to maximize protection and efficiency for breeding and feeding for smaller, vulnerable fish. Other fish move with specialized speed and elongation in order to successfully hunt their prey. Beyond the design and function of fish, they are beautiful and varied creatures that make up a core tenet of marine life.