Q:

What makes a fish a fish?

A:

By definition, fish are animals that live in water, have gills and lack limbs. They are also chordates, which means they have a backbone-like structure that provides support for the body and acts as an anchor for the major muscles.

Animals that live in water but have limbs rather than fins are not fish, but rather amphibians or reptiles. Most fish are cold-blooded, but there are a few exceptions to this generalization, including tuna, swordfish and certain types of sharks. Some animals that have the word "fish" in their name are not actually fish. For example, jellyfish are invertebrates, not chordates, and do not meet the definition of a fish.

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    What type of plant is safe for your goldfish?

    A:

    Safe plants for a goldfish in an aquarium include java ferns, sword plants (also known as Amazon swords), water sprites and banana plants. For pond goldfish, use plants like duckweed, water hyacinths, water lilies, anacharis, cabombas or bog plants.

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    What tropical fish can live together?

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    How long is a goldfish's memory?

    A:

    In spite of the popular myth that goldfish have only a 3-second memory, research conducted at Plymouth University has demonstrated that goldfish have a memory span of up to three months. These studies have also established that goldfish are able to associate time with feeding.

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