What Is the Open Ocean?
Are you looking for an easy way to teach your child about the open ocean? We’ve put together a set of free materials that parents and teachers can use right away. In this lesson, your child will dive into the boundless realm of the open ocean.
We’ll explore the differences between bony fish and cartilaginous fish, and uncover how they thrive in the vast open ocean. Explore science more engagingly with captivating 3D videos and interactive quizzes. Download our app to get started!
Table of Contents
What You Will Learn From This Lesson
- The open ocean is a vast habitat far from the shore.
- Bone structure and gills help categorize different fish species.
- Marine mammals utilize lungs and lactation for survival.
What is the open ocean?
The open ocean is a vast and expansive environment located far from the shore. It is a massive area of the sea where the water stretches out significantly, creating a wide space for many unique marine animals to explore.
What sea animals live in the open ocean?
Within the open ocean, scientists categorize fish by examining three defining physical features: their bones, breathing structures, and fin shapes.
Bony fish, like the ocean sunfish, possess hard skeletons and symmetrical tail fins. These giants can grow as long as 5.5 meters (18 feet), making them the largest bony fish in the world. You can also identify them by their protective gill covers and nostrils located on the upper part of the head.
In contrast, cartilaginous fish like the great white shark have flexible skeletons made of cartilage and asymmetrical tail fins. It is scientifically defined by its visible gill slits and nostrils located on the lower part of its snout. For species like the devil ray, where other features are less obvious, these distinct gill lines remain the key way to tell them apart.
Fun Fact
- The sunfish floats on its side to soak up sunbeams like a giant, flat solar panel.
- To stay safe from extinction, a single mother sunfish can lay 300 million eggs at once.
- Sunfish let hungry seabirds land on them to peck off itchy parasites like a natural spa treatment.
- A great white shark has a dark back so prey looking down can’t see it against the deep water.
Vocabulary
- Bony Fish: Fish with hard skeletons, symmetrical tails, and protective gill covers.
- Cartilaginous Fish: Fish with skeletons made of soft cartilage and visible gill slits.
- Gill Slits: Visible vertical lines on the side of a cartilaginous fish’s head used for breathing. They allow water to exit after passing over the gills.
- Symmetrical Tail: A fin where the top and bottom halves are equal in shape. Most bony fish have this feature, which helps them swim straight and steady.