Oceans have always fascinated us. This set of worksheets examines some of the more popular sea creatures.

Ancient stories are filled with accounts of sea monsters, sunken civilizations, and other mysteries. While we have yet to discover Atlantis or mermaids, the uncharted depths of the world's oceans continue to provide new discoveries each year. Since oceans account for more than seventy percent of the surface of the Earth, there is a vast amount of unexplored areas on our planet. In fact, a mathematician that went back through the history of Oceanic exploration put the amount that we have explored at less than five percent of the total area of oceans. It is also no surprise that over ninety percent of Earth's living creature are found in that very body water as well. Since there is so much life that we did not realize existed, it might also be good to know that the largest and longest earth forms are found in the ocean. The Mid-Ocean Ridge is the longest chain of mountains in the world and almost entirely under water. It may not surprise you that there are also underwater rivers and lakes down there too. While many people think the tropical rainforests are keeping our us breathing oxygen, just about seventy percent of the world's oxygen supply comes from our ocean's marine plants and algae.

This collection of worksheets explores the diets, characteristics, and habits of many familiar ocean-dwelling animals. Each short reading passage is accompanied by two sheets of questions for students. Answer keys have been provided for each. Fun Fact: While oceans cover over 70% of the surface of the Earth, man has explored less than 5% of them.

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Many Americans take shark cartilage as a dietary supplement to restore cartilage and prevent joint pain.

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Multiple Choice Questions

Scientists know that species of sharks date back to the Age of Fishes, the Devonian Period that occurred 350 to 400 million years ago.

Short Answer Questions

Sharks look ferocious when they open their jaws because they have several rows of sharp teeth.

Whales - Reading Passage

Even though whales live in the ocean and never deliberately come on land, they are mammals.

Whales - Multiple Choice Questions

Cetaceans include all the species of whales, dolphins and porpoises. Technically, some animals that people normally call whales are actually dolphins in the scientific classification of animals, for example, pilot whales and killer whales.

Short Answer Questions

The diet of whales depends upon the species. For example, humpback and blue whales eat only plankton and krill.

Rays - Reading Passage

Rays are one of the most interesting looking creatures on earth. Rays are flat and swim through the ocean waters as if they were flying inside a giant opened cape.

Multiple Choice Questions

In the scientific classification of fish, chrondrichthyes are further divided into selachians and batoids.

Short Answer Questions

dators. Rays are generally solitary creatures. The diet of most species of rays is varied and includes fish and shrimp.

Octopus - Reading Passage

Mollusks have a soft body so they do not have an internal skeleton. Instead, some mollusks, like clams and snails but not octopuses, have an outside skeleton called an exoskeleton.

Multiple Choice Questions

Cephalopods are composed of a head, a body containing internal organs, and appendages that are attached to the head.

Short Answer Questions

Since an octopus is a cephalopod, these arms are attached directly to the head. Each arm has two rows of suction openings called suction cups; these openings have the equivalent of taste buds that help the octopus find food.

Dolphins - Reading Passage

Dolphins are classified as cetaceans. Characteristics of cetaceans are flippers instead of front legs and a horizontally flattened tail instead of hind legs.

Multiple Choice Questions

The dolphin species most Americans are familiar with is the bottlenose dolphin which has a long, slender nose.

Short Answer Questions

Dolphins are large creatures, attaining a length of 13 feet and a weight of 1,000 pounds, depending on age, gender, species and habitat.

Jellyfish or Sea Jellies

Jellyfish are adaptable creatures that can be found in every ocean and at every depth of the ocean.

Multiple Choice Questions

The primitive nervous system of sea jellies can detect and respond to light and the presence of food.

Short Answer Questions

A distinguishing feature of sea jellies is the presence of four to eight dangling arms; most sea jellies also have tentacles that are attached to the bell.

Crabs - Reading Passage

In the scientific classification of all animals, crabs belong to the phylum of arthropods. The phylum for arthropods includes insects, spiders, shrimp, and crabs.

Multiple Choice Questions

Arthropods have a segmented body; this means that they have distinct sections of their bodies that are hinged together.

Short Answer Questions

Crabs are omnivorous, which means they eat plants and other animals. Crabs like to eat primitive plants called algae as well as clams, worms, fungi and bacteria.

Coral - Reading Passage

Divers enjoy exploring tropical coral reefs because of the wide variety of unique marine life that inhabit them. Most people believe that coral reefs exist only in tropical shallow water near islands or the continental coast.

Multiple Choice Questions

An individual coral organism is the polyp and polyps of a particular coral species are genetically identical.

Short Answer Questions

Like sea jellies, coral possess tentacles and nematocysts. The tentacles are like small fingers at the top of a coral polyp. T

Seals - Reading Passage

Seals are ocean mammals that spend part of their time on land. Seals are streamlined for efficiently swimming and diving in the ocean but they come on land or ice to rest, mate, give birth to pups and shed their coats, called molting.

Multiple Choice Questions

There are thirty-three species of pinnipeds divided into three major categories: true seals; eared seals which include sea lions and fur seals; and the walrus.

Short Answer Questions

The hind flippers of eared seals have claws and allow these species to walk on land on all four flippers instead of dragging their hind end. Eared seals use their front flippers as paddles for swimming.

Sea Turtles Passage

Turtles are reptiles, which mean they are cold-blooded; that is, they cannot make their own body heat but instead rely on the outside environment for warmth.

Multiple Choice Questions

Sea turtles have a shell; the top of the shell is called a carapace while the underside of the shell is called a plastron.

Short Answer Questions

Sea turtles are large in size; the largest species is the leatherback sea turtle which can grow to 4 to 6 feet in length and weigh 400 to 1,000 pounds.