Krill

Krill are tiny sea animals.

They live in every ocean. Most krill are clear.

They have small legs to help them eat. They use these legs like tiny combs. This helps them catch tiny bits of food in the water. Many big animals eat krill.

Whales, seals, and penguins love them. Krill move up and down in the sea each day. This helps provide food for many animals. They are a very important part of ocean life.

Krill are tiny sea animals. They live in all of the world's oceans.

Most krill have clear shells. These shells are called exoskeletons. Their bodies have three main parts. They have a head and a middle part joined together. They also have an abdomen, which is the tail area.

Krill are very important to the ocean food chain. They eat tiny algae called phytoplankton. They use their legs like small combs to filter food from the water. Many large animals eat krill. This includes fish, penguins, and seals. Even the huge blue whale eats them!

Many krill can make their own light. They use tiny organs called photophores to do this. This light might help them find friends or hide from enemies. Krill also move up and down in the water every day. They stay near the surface at night. During the day, they swim to deeper water. This helps move food to different parts of the sea.

Krill are small sea animals that live in every ocean on Earth.

They belong to a group called crustaceans. This means they have a hard outer shell called an exoskeleton. Most krill have bodies that are clear or transparent. Their bodies have three main parts: a head and middle section joined together, an abdomen, and a tail fan.

Krill are a vital link in the ocean food chain. They eat tiny plants called phytoplankton. Many large animals rely on krill to stay alive. This includes penguins, seals, squid, and even the huge blue whale.

Krill have a very interesting way of eating. Most of them are filter feeders. They use their front legs, called thoracopods, like tiny combs. These legs sweep through the water to catch small bits of food. Some krill are omnivores, which means they eat many different things. A few types are even carnivores that hunt small fish larvae.

This feeding helps move energy through the sea. They take tiny algae and turn it into food for bigger animals. Without krill, many ocean creatures would have nothing to eat.

Scientists have studied krill for a long time to understand them. In 1830, Henri Milne-Edwards first described a type of krill. Later, in 1883, Johan Erik Vesti Boas split certain groups of sea life apart. For many years, experts debated how krill are related to other animals. Some thought they were close to prawns. Others thought they were more like mysids.

Today, we use molecular studies to look at their DNA. This helps us see how they fit into the tree of life.

There are many different kinds of krill around the world. The family Euphausiidae has 85 different species. The largest group is called Euphausia, which has 31 species. One very special kind is the Antarctic krill.

In the Southern Ocean, there are about 379 million tonnes of this krill. This is a huge amount of life! Other species, like the Northern krill, live in the Atlantic Ocean. Some krill, like the Bentheuphausia amblyops, live very deep in the dark water.

Krill do amazing things to survive in the deep sea. Most krill can make their own light using organs called photophores. They use a special reaction to create this glow. This might help them hide from predators or find friends.

They also move up and down in the water every day. This is called a vertical migration. They swim near the surface at night to eat. During the day, they swim down to deeper, darker water. This movement helps move nutrients through the whole ocean.

Krill are small, marine crustaceans belonging to the order Euphausiacea. They live in every ocean on Earth.

These creatures are vital to the ocean's food web. They act as a trophic level connection. This means they link the tiny producers at the bottom to much larger predators. Without krill, many ocean ecosystems would struggle to survive. They turn microscopic energy into a food source for massive animals.

Most krill are filter feeders that eat phytoplankton. Phytoplankton are tiny, single-celled algae.

Krill use their front appendages, called thoracopods, to filter food. These legs act like fine combs to catch diatoms. Diatoms are a specific type of unicellular algae. Some krill are omnivores, meaning they eat both plants and small animals. A few species are even carnivores that hunt fish larvae.

This feeding process helps move carbon through the ocean.

Krill anatomy is quite specialized. Their bodies consist of three main parts. First is the cephalothorax, which is a fused head and thorax. Next is the abdomen, which holds ten swimming appendages. Finally, they have a tail fan.

Most krill have a transparent exoskeleton made of chitin. This clear shell helps them hide. They also have complex compound eyes. Many species use photophores to create light. Photophores are organs that use a chemical reaction called bioluminescence. This involves a pigment called luciferin and an enzyme called luciferase. This light might help with mating or camouflage.

Scientists have spent many years studying krill taxonomy. Taxonomy is the science of naming and grouping organisms. In 1830, Henri Milne-Edwards first described a krill species. Later, in 1883, Johan Erik Vesti Boas split certain groups apart. For a long time, experts debated if krill were related to prawns or mysids. This debate happened because krill share features with both groups. Today, molecular studies of DNA help scientists understand their true history. These studies suggest the order Euphausiacea is monophyletic. This means all krill share a single common ancestor.

The family Euphausiidae is very large. It contains 10 different genera and 85 species. The genus Euphausia is the biggest, with 31 species. One rare species is Bentheuphausia amblyops. It is a bathypelagic species, meaning it lives in the deep ocean. It is considered the most primitive living krill.

Most other krill species are much more common. They live in different parts of the world's oceans.

In the Southern Ocean, the Antarctic krill is incredibly abundant. Its estimated biomass is about 379 million tonnes.

This is one of the largest total biomasses of any single species. Over half of this mass is eaten every year. Predators include whales, seals, penguins, and squid. Baleen whales, like the blue whale, rely on them. Krill also participate in diel vertical migrations. This is a daily movement where they swim up at night and down during the day. This movement can reach depths of 400 metres.

Krill are also important to human industries. They are fished commercially in the Southern Ocean and near Japan. Much of the catch goes to aquaculture and aquarium feeds. It is also used as bait for sport fishing. The pharmaceutical industry uses krill as well. In some places, people eat them directly. In Japan, they are known as shirasu. In Spain and the Philippines, they are called camarones. In the Philippines, they are also called alamang. They are used to make a salty paste called bagoong.