genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
in the
catfish
Catfish (or catfishes; order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the three largest species alive, ...
family Chacidae. These fish are commonly known as squarehead catfishes, frogmouth catfishes, or angler catfishes. These unusual fish have a sedentary lifestyle and spend much of their time motionless.
The name ''Chaca'' is because, when removed from the water, they will rapidly repeat the sound "chaca". Only ''C. chaca'' makes these sounds; the other species do not.
Species
The four currently recognized species in this genus are:Ng, H.H. & Kottelat, M. (2012): Chaca serica, ''a new species of frogmouth catfish (Teleostei: Siluriformes) from southern Borneo.'' Zootaxa, 3258: 37–45.
* ''
Chaca bankanensis
''Chaca bankanensis'' is a species of angler catfish found in the Sundaland region, where it occurs in Brunei, Indonesia, Malaysia, and Thailand. It is found in peat swamp
Peat swamp forests are tropical moist forests where waterlogged so ...
Kottelat
Maurice Kottelat (born 16 July 1957 in Delémont, SwitzerlandC ...
, 2012
Distribution and habitat
''Chaca'' species are found in
fresh water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...
from eastern
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
to
Borneo
Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...
.
''C. chaca'' is found in rivers, canals, and ponds of grassland, scrubland, deciduous forest, and rainforest habitats. On the other hand, ''C. bankanensis'' is only found in the rainforest, where it inhabits peat.
Appearance and anatomy
''Chaca'' catfish have elongated, broad, and flattened heads. The mouths are terminal and very wide. Three or four pairs of
barbels
In fish anatomy and turtle anatomy, a barbel is a slender, whiskerlike sensory organ near the mouth. Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the zebrafish, the black dragonfish and some s ...
are found, though if the nasal barbels are present, they are minute. These fish grow to a length of about .
The dorsal fin is short and possesses strong, serrated, fin spines, which are strong enough to inflict wounds.
Ecology
These fish live in soft substrates where they bury themselves as camouflage, both for protection and to feed. These fish are ambush predators. They feed on prey such as small fish, including
cyprinid
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest verte ...
s and
pupfish
Pupfish are a group of small killifish belonging to ten genera of the family Cyprinodontidae of ray-finned fish. Pupfish are especially noted for being found in extreme and isolated situations. They are primarily found in North America, South Am ...
es. They lie in wait, well camouflaged, in preparation for prey to swim by. Sometimes, they use their maxillary barbels (attached to the upper jaw) to lure
prey fish
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the fo ...
closer to their mouths, similar to a worm jerking in the water, although this behavior is contested by some aquarists, who do not observe this behavior. When the catfish is ready to strike, the ''Chaca'' will open its large mouth rapidly, creating a vacuum that pulls in water and its prey, which may be up to half the fish's own length. These fish are also able to use this large mouths as a means of propulsion; when frightened, they will gulp a large amount of water and expel it through their gills.
In the aquarium
''Chaca'' species are occasionally available as
aquarium
An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...
fish. They are nocturnal and are usually inactive. A bizarre phenomenon is shown in that ''Chaca'' species appear to lower the pH of the water, so maintenance of water chemistry is necessary. These fish have been bred in captivity.