Blennies – Blennioidei – are small elongated and diverse fish species that feature large mouths and long dorsal and pelvic fins. There are a total of 833 species of blennies categorized in six distinct families. These are benthic fish somewhat similar to gobies, but almost eel-like in appearance. They use whisker-like structures known as cirri to facilitate food consumption due to their unique feeding choices and habits.
There is lengthy debate about the most efficient type of food associated with blennies. Most species are commonly known to eat a wide variety of algae, small invertebrate species, shrimp, as well as micro-algae. In the wild most blennies will take to pick at rocks, sediments, sand, shells and anywhere else that they can find minuscule food particles. They aren’t very picky, and most species are known to thrive on small benthic crustaceans, mollusks, as well as brine and mysis shrimp. Algae species such as Rhodohphyte and Phaeophyte, as well as blue green algae and filamentous green algae are commonly on the menu.
Blennies are commonly found in the vicinity of small rock crevices, empty shells or other small, secluded and protected areas, where they guard their territory to allow the females to lay their eggs. The female proceeds to enter the protected sanctuary and lay her eggs. The eggs will stick to the rock, sand or shell, and are later fertilized by the male. The male then guards the eggs and fans them to provide them with adequate oxygen until the time they hatch. Once they do, the young blennies (Blennioidei) swim up to the surface to feed on microscopic plant and animal particles, as well as plankton that are carried by the current.
As benthic fish, blennies spend most of their time near or on the actual seabed. They will make a home of the smaller rock crevices of the reef or inhabit empty shells left behind by shellfish. Some species of blennies can also be found in muddy, shallow waters that have an abundance of algae and micro-algae. They spend a great deal of time near the bottom, where their behavior can range from solitary and territorial to easily forming small social groups. Blennies (Blennioidei) can usually be found near Australia, the Indo-Pacific, Central America, as well as most tropical regions that feature a stable, warm climate.