Schools of armoured catfishes – do they really exist?

The armoured catfish of the genera Corydoras, Scleromystax, Brochis and Aspidoras are often referred to in the aquaristic literature as “swarm fish”, combined with the recommendation to always maintain at least 4-6 specimens together. In the aquarium, however, armoured catfish swim in a swarm only once in a while, are they really schooling fish?

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Profile: Freshwater Mussels & Snails

Since the very beginning of the aquarium hobby snails have been maintained in the aquarium to consume algae and wastes. Most aquaria are home to small, inconspicuous snails without the owner introducing them. But there are also large, attractive species...

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Will snakeheads be banned in the EU?

On Saturday I had a preview of the latest "improvement" in the EU-wide list of prohibited invasive animal and plant species. The third revision is now imminent, and yet again aquarium and pond plants are scheduled to be banned, specifically...

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The smallest fishes in the world

The smallest fishes in the world are the dwarf cyprinids of the genus Paedocypris. There are three scientifically described species of these dwarfs: two from  Borneo and one from Sumatra and an offshore island. They are Paedocypris carbunculus (Kalimantan Tengah, Borneo), P. micromegethes (Sarawak, Borneo), and P. progenetica (Sumatra and Bintan). Following their discovery during the 1990s it was thought that they might even be the smallest vertebrates of all, but that honor currently belongs to the fro

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A mysterious new marine angelfish

The marine angelfishes are without doubt among the most beautiful of all marine fishes. Six species occur on the western coast of the Atlantic. The discovery there of a new species must rank as a sensation, as the area has been very well explored ichthyologically.

The six species that occur there are the Pygmy Angelfish (Centropyge argi), the Rock Beauty (Holacanthus tricolor), the Gray Angelfish (Pomacanthus arcuatus), the French Angelfish (Pomacanthus paru), the Blue Angelfish (Holacanthus bermudensis), and the Queen Angelfish (Holacanthus ciliaris). You should know that the last two species can be told apart only by their differing coloration.

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One for everyone: Neocaridina heteropoda

Dwarf shrimps of the genera Caridina and Neocaridina are the all the rage in the 21st century aquarium hobby. When Uwe Werner published the very first book on the subject in 1998, Shrimps, crayfishes, and crabs in the freshwater aquarium (Aqualog), a few species were already known in the hobby. But it was virtually impossible to get reliable information on the little creatures imported more or less universally as bee or bumblebee shrimps.

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Why did fishes venture onto land? Part 2

Last time we looked at the “living fossils”, ancient fishes that breathe using lungs and have stout scales and limb-like fins or fins on stalks. None of the species in existence today displays any serious inclination to venture onto land, and hence they don’t answer the question of why at some time in the past fishes made their way ashore. Perhaps there are modern fish species that can provide an answer?

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