Blennies are members of the "Family Blenniidae" which contains 53 genera and about 350 species. The most kind of Blennies are bottom-dwelling fishes and fun to watch, can be kept in both reef or fish-only aquarium. Some species can be quite colorful while others are drabber and covered with spots and stripes to blend in with their surroundings. Others have venomous fangs and prey on small invertebrates and other fishes. Many have their teeth in their lips and use them for scraping algae from the surface of rocks.
The habitats of blennies range from rocky pools to sandy beaches, reefs, and beds of kelp. They are mainly bottom dwelling fish but some range to depths of about 450 m. A few blennies live in freshwater streams and rivers. Blennies are generally hardy fishes, easy to care for and do not require a large tank.
The most popular aquarium specimens belong to the genera Ecsenius, Salarias, and Meiacanthus. Ecsenius is the largest genus with at least 46 identified species. They basically an algae consuming species and one of the most popular genus, often colorful and in any case an quite interesting fish.
Unfortunately, most Blennies are highly territorial and will constantly be fighting if there is more than one species per tank. The exception to this rule is fish from the genus Meiacanthus, which can be kept together in a small group. In any case they should be kept with other peaceful, non-predatory tankmates.
