Marine Life: Most Popular Articles
Starfish - sea stars - are marine invertebrates that are a variety of colors, shapes and sizes, although all resemble a star. Starfish are familiar marine animals and fascinating creatures. Here are 10 facts about starfish, including one about how they are not actually a fish.
Facts about seahorses, including the number of seahorse species, where seahorses live, what they eat and how they reproduce.
There are several hundred species of sharks, ranging in size from less than ten inches to over 50 feet. Learn shark facts about these amazing fish with a fierce reputation, but fascinating biology.
What is the deepest part of the ocean? Learn about the ocean's deepest point, how deep it is, and what lives there.
Learn why a killer whale - orca's - dorsal fin collapses, or flops over, when it is in captivity.
What is the salary of a marine biologist? Learn about a marine biologist's job and salary range.
There are about 86 species of cetaceans - whales, dolphins and porpoises in the Order Cetacea, which is further divided into two sub-orders, the Odontocetes and the Mysticetes. Learn about and see photos of featured cetacean species.
Do sharks lay eggs? Here you can learn about ways sharks reproduce, including whether they lay eggs or give birth to live young.
Facts about scallops. Learn about where scallops live, how big they grow, what they eat and how they reproduce. When you eat a scallop, what part are you actually eating?
When you think of lobster, do you think of a bright red crustacean on your dinner plate, or a territorial creature roaming caves in the ocean? Despite their fame as a delicacy, lobsters also have fascinating lives. Learn some lobster facts about this iconic marine creature here.
The whale shark is the world's biggest fish, maxing out at about 65 feet in length and weighing up to about 75,000 pounds.
Sharks need to keep water moving over their gills so that they receive oxygen. So that seems to mean that they need to keep moving all the time...or do they? How do sharks sleep? Even though sharks need to keep water moving over their gills to receive oxygen, some sharks need to keep moving to do this, while others don't. Either way, sharks, like other marine animals, don't seem to fall in a deep sleep like we do.
There are 32 species of seals. Learn facts about some of these seal species here.
Sea turtles are classified in the Class Reptilia, Subclass Anapsida and Order Testudines. There are seven recognized species of sea turtles, six of which (the hawksbill, green, flatback, loggerhead, Kemp's ridley and olive ridley turtles) are in the Family Cheloniidae, with only one (the leatherback) in the Family Dermochelyidae. All seven species of sea turtles are listed under the Endangered Species Act.
Marine algae, more commonly known as seaweeds, come in all shapes and sizes. Here is an introduction to brown, red and green algae with some examples of each type of seaweed.
How do dolphins sleep? Find out about how dolphins sleep - you may be surprised at the answer.
Tunas are large, powerful fish that are distributed worldwide from tropical to temperate oceans. They are members of the family Scombridae, which includes both tunas and mackerels. Learn about the several species of fish known as tuna, and their importance commercially and as gamefish.
Seals are divided into two families, the Phocidae, the earless or ‘true’ seals (e.g., harbor or common seals), and the Otariidae, the eared seals (e.g., fur seals and sea lions). This article contains facts about both types of seals.
The whale shark is the world's biggest shark species. Growing to a length of about 65 feet and weighing about 75,000 pounds, this streamlined fish is really a gentle giant.
Information about starfish, including facts about starfish species, images, starfish habitat, feeding and reproduction.
Learn about the term marine biologist - what a marine biologist is, what marine biologists do, steps to becoming a marine biologist, and how much marine biologists earn.
When you picture a marine biologist, what comes to mind? Many picture a dolphin trainer, or maybe Jacques Cousteau. But marine biology covers a wide range of activities and organisms, and so does the job of a marine biologist. Here you can learn what a marine biologist is, what marine biologists do, and how you can become a marine biologist.
What is the fastest fish in the ocean? Learn the answer here.
The biggest animal in the ocean, and in the world, is the blue whale (Balaenoptera musculus), a sleek, light-colored giant. The blue whale gets its name from its skin, which is a mottled blue-gray color.
There are seven recognized species of sea turtles, and all are endangered. Learn facts about sea turtles, including where they live, how they reproduce, and what they eat.
Learn 10 facts about killer whales (orcas).
The intertidal zone is the area where land and sea meet, and often includes tide pools. Learn about the unique intertidal zone, tide pools, the types of marine life that live in the intertidal and threats to this habitat.
The group of marine life known as crustaceans includes crabs, lobsters and shrimp - some of the most important marine life to humans. It also includes other animals such as amphipods and isopods. The crustaceans are in the Phylum Arthropoda and Subphylum Crustacea. Here you'll find the definition of crustacean and learn more about crustaceans.
An adaptation is a physical or behavioral characteristic that has developed to allow an organism to better survive in its environment.
Whale shark facts. Facts about whale sharks, including where whale sharks live, what whale sharks eat, where to see whale sharks, and how whale sharks reproduce.
What is a cartilaginous fish? Learn about cartilaginous fish - the group of fish that includes elasmobranchs: sharks, rays and skates.
Sea turtles are reptiles that live in a marine or brackish environment. Learn about sea turtle reproduction, distribution, classification and conservation status.
Do starfish have eyes? Information about starfish (sea star) eyes. While it may appear that starfish have eyes, they do. Learn where the eyes are on a starfish.
There are thousands of species of marine life, from tiny zooplankton to enormous whales. Each is adapted to the specific habitat it occupies. Throughout the oceans, marine organisms must deal with several things that terrestrial life do not, including regulation of salt, obtaining oxygen, and adapting to water pressure. Learn about ways marine organisms survive in the oceans.
Red algae are, not surprisingly, red, purplish or reddish in color. There are about 6,000 species of red algae and they are classified as protists in the phylum Rhodophyta. Red algae species range from simple one-celled organisms to complex, plant-like organisms.
Learn 10 fascinating facts about sea otters.
Green algae range from simple, one-celled organisms to complex, multi-celled organisms. They may also live in large colonies. There are both marine and freshwater green algae species, although we will focus on the marine species here.
Information on the marine life that inhabit the Gulf of Mexico. The Gulf of Mexico supports a wide variety of marine life, including whales, dolphins, manatees,sea turtles, birds, invertebrates and marine algae and plants.
Conchs are a type of sea snail, and are also a popular seafood in some areas. The term 'conch' (pronounced
Learn facts about ocean sunfish - mola mola - how big it is, where it lives, what it eats, and how it reproduces.
Learn about types of marine mammals, including whales, dolphins, porpoises, sirenians including manatees and dugongs and pinnipeds including seals and sea lions.
The shortfin mako shark (Isurus oxyrinchus) appears to be the fastest shark species. Learn more about this speedy shark and other fast shark species.
The short answer: whales are not fish. Whales are mammals, just like you and me. All mammals are endothermic (commonly called warm-blooded), give birth to live young and nurse their young, breathe oxygen from air, and have hair (yes, even whales do!). If you're still not convinced, here are some specific ways that whales differ from fish.
Cetaceans - whales, dolphins and porpoises - are a diverse group of animals ranging in size from just a few feet long to over 100 feet long. While most whales spend their lives offshore in the ocean's pelagic zone, some inhabit coastal areas and even spend part of their lives in fresh water. Learn about how whales feed, reproduce and explore their world.
Brown algae is the largest, most complex type of algae. This type of marine algae is brown, olive or yellowish-brown in color. Brown algae contains contains chlorophyll a and c and a pigment called fucoxanthin, which gives it its color. Types of algae include kelp, rockweeds and wracks in the genus Fucus and free-floating algae in the genus Sargassum.
Want to know the sex of a lobster you've caught or are about to eat? Here's how to tell. Lobsters have feathery appendages called swimmerets underneath their tail. These swimmerets help a lobster swim and are also where a female lobster carries her eggs. Swimmerets also can clue you in to the sex of a lobster.
Almost three-quarters of the Earth is ocean. Here you can learn facts about the ocean, about the major oceans of the world, and what the ocean is like as a marine life habitat.
Whales are mammals, and one of the characteristics common to all mammals is the presence of hair. There are over 80 species of whales, and hair is only visible in some. Whales have hair on their heads as fetuses, but they don't always keep it.
Facts about nudibranchs - learn information on these fascinating sea slugs that live in all the world's oceans. What do nudibranchs eat? How do nudibranchs reproduce? Where can you see a nudibranch? Learn here.
Is it a whale, dolphin or porpoise? These terms are often used interchangeably, but there is a difference. Learn about the terms whale, dolphin and porpoise and how they are used to describe different members of the order Cetacea.
Protists are organisms in the kingdom Protista. These organisms are eukaryotes, meaning they are made up of single or multiple cells which all contain a nucleus enclosed by a membrane.
Many people became familiar with the disastrous effects of oil spills in 1989 after the Exxon Valdez incident in Prince William Sound, Alaska. That spill is considered the worst oil spill in U.S. history -- although the 2010 BP leak in the Gulf of Mexico could prove to be even worse. Overall, the effects of an oil spill on marine life depend on a variety of factors, but can include hypothermia, poisoning, increased predation and other stressors, as well as effects on marine habitat.
While its name may be deceiving, the whale shark is actually a shark, and the largest fish in the world. Whale sharks can grow to 65 feet in length and up to about 75,000 pounds in weight. Females are generally larger than males
Definition of radial symmetry. Learn what radial symmetry is and in which marine organisms it occurs.
Spiracles are found in bottom-dwelling sharks and rays. Spiracles are a pair of openings just behind the animal's eyes that allow it to draw oxygenated water in from above.
The Class Gastropoda includes snails, slugs, limpets and sea hairs - all animals referred to as 'gastropods.' Learn about gastropods and see some examples here.
The term phylum is one of seven major categories that are used to classify organisms. In order of broad to specific, these seven categories are: Kingdom, Phylum, Class, Order, Family, Genus, and Species. This classification system was developed by Carolus Linnaeus in the 18th century
Echinoderms, or members of the Phylum Echinodermata, are some of the most easily-recognized marine invertebrates, many of which are found in tide pools or in the touch tank at your local aquarium. The Phylum Echinodermata includes 4 classes: Stelleroidea (sea stars), Echinoidea (sea urchins and sand dollars), Holothuroidea (sea cucumbers) and Crinoidea (sea lilies and feather stars.) They are a diverse group of organisms, containing about 6,000 species.
Placoid scales (dermal denticles) are tough scales that cover the skin of elasmobranchs (sharks and rays). Even though placoid scales are similar to the scales of bony fish, they are really modified teeth and are covered with a hard enamel.
What type of sharks are most likely to attack? Of the hundreds of shark species, there are 3 most often implicated in unprovoked shark attacks on humans. Learn more about these three species, and how you can prevent a shark attack.
All of our actions, no matter where we live, effect the ocean and the marine life it holds. Even if you live far inland, there are many things you can do that will help marine life. Learn about easy ways that you can help protect marine life, including recycling fishing line, eating sustainable seafood and reducing your carbon footprint.
: "Plankton" is the term that generally refers to the "floaters," the organisms in the ocean that drift
Manatees are herbivores, feeding primarily on aquatic plants. Learn about the types of food manatees eat.
Ovoviviparous animals produce eggs, but instead of laying the eggs, the eggs develop within the mother's body and are birthed live.
Learn about the various species of hammerhead shark, all of which have an interestingly shaped head. They range in size from about 3 to 20 feet long.
Learn about whale watching from shore on the coast of Cape Cod, focusing on whale watching from Provincetown, Massachusetts. See whales from shore in the spring from Cape Cod, MA. Learn viewing tips and what to bring.
Learn how pearls form, including species that make pearls.
Learn about bony fish - what is a bony fish? What are the characteristics of bony fish? You can also learn some examples of bony fish species.
Cetacean is a word used to describe all whales, dolphins and porpoises in the order Cetacea. Learn about the characteristics of cetaceans, including baleen whales and toothed whales and how they survive in the oceans.
Within the oceans, there are many different types of habitat, or environments in which plants and animals live, ranging from freezing polar ice to tropical coral reefs. These habitats all come with their unique challenges and are inhabited by a wide variety of organisms. Learn more about important marine life habitats including mangroves, the intertidal zone and tide pools, coral reefs, seagrasses, the open ocean - pelagic zone, the deep sea and hydrothermal vents.
What do sea otters eat? Learn the answer here.
Information about the cnidaria - the phylum that contains corals, jellyfish, sea anemones, sea pens and hydras. Learn about cnidaria facts, life cycles, where cnidaria are found and examples of cnidarians.
With their very distinctive, flattened snout, sawfish are intriguing animals. What is their "saw?" How
What do seahorses eat? Marine Life.
Seals, sea lions and walruses are all in the order Carnivora and suborder Pinnipedia, thus they are called “pinnipeds.” There are three families of pinnipeds, the Phocidae, or earless or ‘true’ seals; the Otariidae, the eared seals, and the Odobenidae, the walrus. This article focuses on the difference between the earless seals (seals) and the eared seals (sea lions and fur seals).
Where do polar bears live? Find out more.
The deep sea includes the deepest, darkest, coldest parts of the ocean. Eighty percent of the ocean consists of waters in the deep sea greater than 1,000 meters in depth. Deep sea areas are cold, dark, and inhospitable to us humans, but support a surprising number of species that thrive in this deep sea environment. Learn more about what is considered the deep sea, how deep the deepest part of the ocean is, and what challenges marine life face in the deep sea.
An apex predator is an animal who, as an adult, has no natural predators in its ecosystem. The great white shark is an example of an apex predator. Apex predators play an important role in keeping ecosystems in check. Learn more about apex predators and why they are important.
Lobsters are usually a brownish-green in the wild. What happens between the sea and the dinner table to turn them bright red?
Do you know the names of the world's oceans? Here you'll find a list of the oceans of the world, along with where the oceans are found and how big they are.
Starfish, or sea stars, are star-shaped animals that are a variety of shapes, sizes and colors. You might be most familiar with the starfish that live in tide pools in the intertidal zone, but some starfish live in deep water. Learn about sea star classification, reproduction and feeding here.
Learn about the types of sharks with this list of sharks species and facts about each.
Whales are voluntary breathers, meaning they think about every breath they take. That means they can't sleep the way we do. Learn how cetaceans (whales, dolphins and porpoises) sleep, or rest.
Definition of ectothermic. An ectothermic animal is one who cannot regulate its own body temperature, so its body temperature fluctuates according to its surroundings.
Learn about the distribution of killer whales (orcas), and where you could see killer whales.
There are over 80 recognized species of whales, dolphins and porpoises, or cetaceans, and these species are divided into two main groups: the baleen whales and the toothed whales. While they are all considered whales, there are some important differences between the baleen whales and toothed whales.
Profile of the common pygmy seahorse (Hippocampus bargibanti), also known as Bargibant's sea horse, including pygmy seahorse classification, what pygmy seahorses eat, how they reproduce, and where they live.
Sea turtles are reptiles that live in a marine or brackish environment. The flippers of sea turtles are long and paddle-like, making them excellent for swimming but poor for walking on land. There are seven species of sea turtles, several of which inhabit U.S. waters. View images of sea turtles here.
Some think of lobster as a bright red delicacy served up with a side of butter. But the American lobster
There are over 80 species of whales, and each has their own movement patterns, but in general, whales migrate toward the colder poles in the summer and toward the more tropical waters of the equator in the winter. This pattern allows whales to take advantage of the productive feeding grounds in colder waters in the summer, and then when productivity lowers, to migrate to warmer waters and give birth to calves.
The bowhead whale (Balaena mysticetus) got its name from its high, arched jaw that resembles a bow. Bowheads are a cold-water whale that lives in the Arctic. Bowheads are still hunted by natives whalers in the Arctic. Learn about the bowhead whale's distribution, feeding habits, reproduction and conservation status.
The white shark, commonly called the great white shark, is one of the most iconic and feared predators of the ocean. With its razor-sharp teeth and menacing appearance, it certainly looks dangerous. But the more we learn about this creature, the more we learn they are not indiscriminate predators, and definitely don't prefer humans as prey. Learn here about the great white shark, its biology, feeding, reproduction and distribution.
Marine biology is the scientific study of plants and animals that live in salt water. When many people think about a marine biologist, they picture a dolphin trainer. But marine biology is so much more. Learn about the field of marine biology, a marine biologist's tools and the importance of studying the oceans and their marine life and habitats.
Learn about coral reefs. Coral reefs are a center for biodiversity and an important marine habitat. Tropical corals, cold-water corals, the marine life species that inhabit them and the natural and human threats to coral reefs in the oceans are discussed here.
Learn about the Mariana Trench, including where it is located and how deep it is.
Facts about the green sea turtle, including information on the green turtle's natural history, reproduction, distribution and conservation. The green sea turtle (Chelonia mydas) weighs up to 350 pounds and their carapace can be many colors, including shades of black, gray, green, brown or yellow.
The mantle is an important part of the body of a mollusk. It forms the outer wall of the mollusk's body and encloses the mollusk's visceral mass (internal organs), and secretes calcium carbonate to form the mollusk's shell.
Information about the animals in the Phylum Chordata, which includes the vertebrates and animals that have a notochord at some stage in their development. Includes examples of animals that are in the Phylum Chordata.
Baleen is a strong, yet flexible material made out of keratin, a protein that is the same material that makes up our hair and fingernails.
Learn about the type of marine life called skates. Where do skates live? How do they eat and reproduce? Find out more by reading this marine life profile of skates.
The term elasmobranch refers to the sharks, rays and skates, which are in the subclass Elasmobranchii and class Chondrichthyes. The Condrichthyes class includes only one other subclass, the Holocephali (chimaeras), which are unusual fish found in deep water.
The open ocean, or pelagic zone, is the area of the ocean outside of coastal areas, and where you’ll find some of the biggest marine life species, including whales, bluefin tuna, and giant squid.
Information about jellyfish. Learn about jellyfish facts, life cycles, where jellyfish are found and types of jellyfish.
A bivalve is an animal that has two hinged shells. Examples of bivalves are clams, mussels, oysters and scallops. Learn more about bivalves here.
Tips for avoiding a shark attack and what to do if a shark attacks. Learn about the risk of shark attacks and tips for swimming in areas inhabited by sharks.
Learn about the 14 species of baleen whales,and click through to species profiles and images.
Learn about the diverse group of whales known as the toothed whales, which includes the dolphins and porpoises. Click through to profiles of each species to learn even more.
: What Is Kelp? : "Kelp" is the general term for 124 species of brown algae that are in the Order Laminariales
With a population less than 1,100 animals, the Mediterranean monk seal is one of the most endangered marine mammals. Learn more about Mediterranean monk seals - what they look like, where they live, what they eat, how they reproduce, and current threats to the Mediterranean monk seal.
Facts about the brittle stars, basket stars and serpent stars, marine invertebrates that belong to the Class Ophiuroidea, the group of marine invertebrates that contains the brittle stars and basket stars. Learn where brittle stars and basket stars live, how they feed, and how they reproduce.
Gastropods are animals in the Class Gastropoda - the group of organisms that includes snails, slugs, limpets and sea hares. There are over 40,000 species in this class. Envision a sea shell, and you're thinking about a gastropod, although this class contains many shell-less animals as well. Here is a round-up of information on gastropods, including their taxonomy, feeding, reproduction and examples of gastropod species.
What is a sea squirt? Information about sea squirts, also called tunicates.
Definition of endothermic. Endothermic animals are those that must generate their own heat to maintain their body temperature. These animals are commonly referred to as warm-blooded.
A brief history of Atlantic cod fishing, from early fishing using dories and handlines to the modern factory ships used today.
Did you know that sponges are animals? There are thousands of species of sponges, and here you can learn about why these organisms are considered animals, how sponges are classified, how they feed and reproduce, and where they live.
Find a sand dollar shell (test) on the beach? Here you can learn all about sand dollars - what they are, where they live, what they eat and how they reproduce.
What is the largest fish? Learn about the largest fish in the world.
The killer whale , also known as the "orca," is one of the most well-known types of whales. Killer whales
Learn 5 facts about the leatherback turtle - the largest sea turtle.
The term “mangrove” is used to refer to a habitat comprised of a number of halophytic (salt-tolerant) plant species, of which there are more than 12 families and 50 species worldwide. Mangrove are found along tropical and sub-tropical coastlines in Africa, Australia, Asia and North and South America. Mangrove plants have a tangle of roots which are often exposed above water, leading to the nickname “walking trees.”
The basking shark is the second-largest shark species, and can reach lengths up to 30-40 feet and weights up to about 8,000 pounds. They are filter-feeders who are often seen feeding near the surface with their huge mouths agape.
Definition of madreporite, an opening in an echinoderm. Learn more about what a madreporite does and the organisms in which it is present.
The blue whale is the largest animal in the world. Learn where blue whales live, what they eat, how they reproduce, and how many are left in the world.
Going on vacation along a rocky shore? Visiting a tide pool is a great way to see and learn about a wide variety of marine life, and great outdoor activity for families. It may not seem like there's much there from a distance, but look closely at a tide pool and you're sure to meet lots of interesting types of marine life. Tide pooling is a great activity, but do it with the safety of both you and your family, and the marine environment, in mind.
Definition of the term clasper, as used in marine biology.
Seagrass is an angiosperm (flowering plant) that lives an a marine or brackish environment. Learn about seagrasses here.
Hydrothermal vents, located in the deep sea, were discovered relatively recently. It was only about 30 years ago that scientists in the submersible 'Alvin' discovered these undersea
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Facts about the hawksbill sea turtle, including information on the hawksbill turtle's natural history, reproduction, distribution and conservation. The hawksbill sea turtle (Eretmochelys imbricate) grows to lengths of 3.5 feet long and weights of up to 180 pounds.
Chordata is the phylum that includes all the animals that have a notochord, or nerve cord, at some stage of their development. Animals in this phylum are known as chordates. The most well-known chordates are the vertebrates - animals that have a spine.
Learn about the Phylum Mollusca - the mollusks.
Want to learn about invertebrates? Here you can learn the definition of invertebrates, characteristics of invertebrates, and examples of invertebrates.
The Class Reptilia refers to the reptiles - a diverse group of animals that are "cold-blooded" and have
Ocean acidification is a lesser-known global warming problem. Ocean acidification is the process by which the pH of the oceans is lowered due to absorption of carbon dioxide. The oceans have helped the global warming problem for thousands of years by absorbing carbon dioxide. Now the basic chemistry of the oceans is changing because of our activities, with devastating consequences for marine life.
Learn about the blue whale - the largest creature on the planet. Facts about blue whales include the blue whale's size, diet and conservation status.
Arthropods are animals in the Phylum Arthropoda, a very diverse group of organisms that includes insects, crabs, lobsters, scorpions and centipedes. Learn about arthropod characteristics, classification, and examples of marine arthropods.
A mollusk is an animal classified in the Phylum Mollusca. Here you can learn more about mollusks and find examples of mollusks.
Facts about the flatback sea turtle, including information on the flatback turtle's natural history, reproduction, distribution and conservation.
Cephalopods are mollusks in the Class Cephalopoda, which includes octopuses, squid, cuttlefish and nautilus. These are ancient species that are thought to have originated about 500 million years ago. There are about 800 species of cephalopods in existence today.
How salty is the ocean? Learn about how much salt is in the ocean.
Fish anatomy - learn about the basic parts of a fish, with a graphic showing fish external anatomy.
What is Earth Day? When is it celebrated? Learn about the founder of Earth Day and its history.
Information about the lion's mane jellyfish, a huge jellyfish with long tentacles. Learn what lion's mane jellyfish eat, where they live, and how they reproduce.
What is a starfish? Learn about starfish, or sea stars.
Facts about fish, including information on characteristics of fish, types of fish and where fish live.
What do polar bears eat? Learn about the species that polar bears eat.
What is a dolphin? Learn about dolphins, including how many species of dolphins there are, and characteristics of dolphins.
Byssal, or byssus threads are strong, silky fibers made from proteins that are used by mussels to attach to rocks, pilings, or other substrates.
Information on whelks, which are snails in the Class Gastropoda.
A predator is an organism that hunts and kills other organisms for food. Learn more about predators and examples of ocean predators.