Combtooth blenny
Encyclopedia
Combtooth blennies are blennioids; perciform marine fish
of the family Blenniidae. They are the largest family of blennies, with approximately 371 species in 53 genera represented. Combtooth blennies are found in tropical and subtropical waters in the Atlantic
, Pacific
and Indian Ocean
s; some species are also found in brackish and even freshwater
environments.
By far the largest species is the eel
-like hairtail blenny at 53 centimetres in length; most other members of the family are much smaller. Combtooth blennies are active and often highly colourful, making them popular in the aquarium
hobby.
s, burrows in sandy or muddy substrates, or even empty shells. Generally found in shallow waters, some combtooth blennies are capable of leaving the water for short periods during low tide, aided by their large pectoral fins which act as "feet". Small benthic crustacean
s, mollusks and other sessile invertebrate
s are the primary food items for most species; others eat algae or plankton
.
There is one exceptional group of combtooth blennies which deserves special mention: the so-called sabre-toothed blennies
of the genera Aspidontus
, Meiacanthus
, Petroscirtes
, Plagiotremus
, and Xiphasia
. These blennies have fang-like teeth with venom glands at their bases. Species of the genera Aspidontus and Plagiotremus (such as the false cleanerfish) are noted for their cunning mimicry of cleaner wrasse
s: by imitating the latter's colour, form and behaviour, the blennies are able to trick other fish (or even divers) into letting down their guard, long enough for the blennies to nip a quick mouthful of skin or scale.
Some combtooth blennies will form small groups, while others are solitary and territorial. They may be either diurnal
or nocturnal, depending on the species. Females lay eggs
in shells or under rock ledges; males guard the nest of eggs until hatching. In some species the eggs may remain in the oviduct
of the female until hatched. The fry of some species undergo an ophioblennius stage, wherein the fish are pelagic
(i.e., inhabiting the midwater) and have greatly enlarged pectoral fins and hooked teeth.
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of the family Blenniidae. They are the largest family of blennies, with approximately 371 species in 53 genera represented. Combtooth blennies are found in tropical and subtropical waters in the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
and Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
s; some species are also found in brackish and even freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
environments.
Physical description
The body plan of the combtooth blennies is archetypal to all other blennioids; their blunt heads and eyes are large, with large continuous dorsal fins (which may have 3-17 spines). Their bodies are compressed, elongate and scaleless; the small, slender pelvic fins (which are absent in only two species) are situated before the enlarged pectoral fins, and the tail fin is rounded. As their name would suggest, combtooth blennies are noted for their comb-like teeth lining their jaws.By far the largest species is the eel
Eel
Eels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
-like hairtail blenny at 53 centimetres in length; most other members of the family are much smaller. Combtooth blennies are active and often highly colourful, making them popular in the aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
hobby.
Habitat and behaviour
Generally benthic fish, combtooth blennies spend much of their time on or near the bottom. They may inhabit the rocky crevices of reefReef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, burrows in sandy or muddy substrates, or even empty shells. Generally found in shallow waters, some combtooth blennies are capable of leaving the water for short periods during low tide, aided by their large pectoral fins which act as "feet". Small benthic crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, mollusks and other sessile invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s are the primary food items for most species; others eat algae or plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
.
There is one exceptional group of combtooth blennies which deserves special mention: the so-called sabre-toothed blennies
Sabre-toothed blenny
The sabre-toothed blenny, Aspidontus taeniatus, is a species of blenny that mimics the "dance" of Labroides dimidiatus; a similarly colored species of cleaner wrasse. It tricks fish into offering their underparts to be cleaned. Instead of eating parasites from the scales of the fish, the...
of the genera Aspidontus
Aspidontus
Aspidontus is a genus of combtooth blennies found in the Pacific and Indian oceans.-Species:* Lance blenny, Aspidontus dussumieri * False cleanerfish Aspidontus taeniatus...
, Meiacanthus
Meiacanthus
Meiacanthus is a genus of combtooth blennies found in the western Pacific and Indian oceans. Many species in this genus make their way into the aquarium trade. The genus name Meiacanthus refers to most species having relatively few dorsal fin spines...
, Petroscirtes
Petroscirtes
Petroscirtes is a genus of combtooth blennies found in the western Pacific, and Indian oceans.-Species:* Arabian fangblenny, Petroscirtes ancylodon * Striped poison-fang blenny mimic, Petroscirtes breviceps...
, Plagiotremus
Plagiotremus
Plagiotremus is a genus of blennies, in particular combtooth blennies, found throughout the Pacific and Indian oceans.-Species:* Sabertooth blenny, Plagiotremus azaleus * Ewa blenny, Plagiotremus ewaensis...
, and Xiphasia
Xiphasia
Xiphasia is a small genus of combtooth blennies found in the Pacific and Indian Oceans. There are two species in this genus.-Species:* Japanese snake blenny, Xiphasia matsubarai...
. These blennies have fang-like teeth with venom glands at their bases. Species of the genera Aspidontus and Plagiotremus (such as the false cleanerfish) are noted for their cunning mimicry of cleaner wrasse
Wrasse
The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 82 genera, which are divided into nine subgroups or tribes....
s: by imitating the latter's colour, form and behaviour, the blennies are able to trick other fish (or even divers) into letting down their guard, long enough for the blennies to nip a quick mouthful of skin or scale.
Some combtooth blennies will form small groups, while others are solitary and territorial. They may be either diurnal
Diurnal animal
Diurnality is a plant or animal behavior characterized by activity during the day and sleeping at night.-In animals:Animals that are not diurnal might be nocturnal or crepuscular . Many animal species are diurnal, including many mammals, insects, reptiles and birds...
or nocturnal, depending on the species. Females lay eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
in shells or under rock ledges; males guard the nest of eggs until hatching. In some species the eggs may remain in the oviduct
Oviduct
In non-mammalian vertebrates, the passageway from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. These eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body...
of the female until hatched. The fry of some species undergo an ophioblennius stage, wherein the fish are pelagic
Pelagic zone
Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...
(i.e., inhabiting the midwater) and have greatly enlarged pectoral fins and hooked teeth.