fish

A flathead gudgeon on the bottom while swimming

European Weatherfish Can the European Weatherfish Be Kept in a Garden Pond or Aquarium?

The European weatherfish, also known as the mud loach, is a cold-water fish. But can it be kept at home?

Mysterious Journey Eels Need the Bermuda Triangle for Reproduction—and No One Knows Why

The Mystery of Eels: Why They Migrate to the Bermuda Triangle to Reproduce–and How Humans Block Their Path

A deep-sea snailfish that looks like a Pokémon

New Species Researchers Discover Deep-Sea Pokémon

Like Pokémon of the Deep Sea: Researchers Discover New Snailfish Species at 4,000 Meters – Featuring Suction Discs, Bumpy Skin & Gliding Morphology.

For Means, Foreground, and Background The 12 Best Plants for a Healthy Freshwater Aquarium

The best plants for freshwater aquariums not only enhance the aesthetic appeal but also offer multiple benefits for the aquarium inhabitants.

Marine fish swim in a saltwater aquarium above coral.

Features, Price, Maintenance Freshwater or Saltwater Aquarium? An Overview of the Differences

When purchasing an aquarium, the question arises whether it will be a freshwater or saltwater aquarium. PETBOOK highlights the differences.

For Garden and Balcony What Animals Can Be Kept in a Small Pond?

A small pond enhances a garden or balcony without requiring construction. But what animals can be kept in it?

Moray eel with open mouth and cleaner shrimp

Like in the Movie "Alien" These Eerie Fish Have a Second Jaw

Moray eels are inherently frightening. Few people know that some species have two sets of jaws equipped with sharp teeth.

Cold Water Fish How to Keep and Care for Sticklebacks in an Aquarium or Garden Pond

The stickleback is a popular cold-water fish and garden pond inhabitant in Germany. What you need to keep and care for it.

Study Clownfish Actively Supply Their Anemone with Food

Clownfish and anemones are an example of a symbiotic relationship in the animal kingdom. This probably also includes active feeding.

Local Fish Keeping and Caring for Bitterlings in an Aquarium or Garden Pond

The bitterling is a popular fish for garden ponds or cold-water aquariums, but it is increasingly losing its habitat.

Pufferfish Torquigener albomaculosus in front of an underwater garden it has created

Looks like mandalas This fish creates works of art to attract females

Mandalas often appear in the sea sand off Japan. Today, scientists know who is responsible for this: the artist pufferfish.

Freshwater Fish from South Asia How to Properly Care for Honey Gouramis in an Aquarium

The honey gourami—also known as the honey dwarf gourami—is the smallest member of the labyrinth fish family, which, in addition to their gills, possess a labyrinth organ. This organ allows them to breathe atmospheric oxygen.

Hariotta avia Ghostly new shark species discovered in the deep sea

Less is known about the deep sea than about the moon. A newly discovered species of ghost shark is also very mysterious.

Freshwater aquarium These 5 ornamental fish are suitable for beginners

There are many different species for aquariums. We explain here which ornamental fish are suitable for beginners.

Two Sumatra barbs swim toward each other

Lively freshwater fish How to Keep the Sumatra Barb in an Aquarium

The Sumatra barb is a popular choice for aquariums due to its appearance and lively behavior. However, there are several considerations to keep in mind when caring for them.

Clownfish that appears to have eyes on its tongue

Cymothoa exigua This parasite replaces the tongues of fish

Some fish seem to have eyes on their tongues. The reason for this is quite disgusting. PETBOOK explains how and why this happens.