''Callichthys callichthys'', the cascarudo, armored catfish, bubblenest catfish, hassar, or mailed catfish, is a subtropical

freshwater 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 in ...

fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% ...

belonging to the subfamily Callichthyinae of the family

Callichthyidae Callichthyidae is a family of catfishes (order Siluriformes), called armored catfishes due to the two rows of bony plates (or scutes) along the lengths of their bodies. It contains some of the most popular freshwater aquarium fish, such as many s ...

Taxonomy

It was originally described as ''Silurus callichthys'' by Linnaeus in 1758. It is likely to represent a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

Distribution

''C. callichthys'' is distributed in all major river drainages of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...

. It is very wide-ranging, extending from

Trinidad Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...

Buenos Aires Buenos Aires ( or ; ), officially the Autonomous City of Buenos Aires ( es, link=no, Ciudad Autónoma de Buenos Aires), is the Capital city, capital and primate city of Argentina. The city is located on the western shore of the Río de la Plata ...

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

, including the upper Amazon River and

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

systems.

Description

The fish will grow in length up to eight inches (20 centimeters). The females are larger and more robust, and are a dull olive-green, while the males are brighter in color, exhibiting a delicate blue or violet sheen laterally, with a more developed and longer pectoral fin spine that is reddish-brown and edged with orange or reddish-orange.

Ecology

It lives in a variety of water types, from anoxic conditions (slack water zones surrounded by dense vegetation) to slightly turbid, but free-flowing, streams. It can be found in waters with pH range of 5.8 to 8.3, a water hardness of 0–30 dGH, and a temperature range of 64–83 °F (18–28 °C). When its biotype becomes dry, it can move out of the water, due to its ability to swallow air and use its intestines to absorb oxygen from the atmosphere, to find more water. It feeds at night on

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

s, and

plant Plants are predominantly Photosynthesis, photosynthetic eukaryotes of the Kingdom (biology), kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all curr ...

matter. Juveniles feed on rotifers, in addition to the microcrustaceans and aquatic insect larvae they find when digging into the substrate. During reproduction, the male's belly turns orange and its pectoral spines become longer and thicker. The male builds a

bubble nest Bubble nests, also called foam nests, are created by some fish and frog species as floating masses of bubbles blown with an oral secretion, saliva bubbles, and occasionally aquatic plants. Fish that build and guard bubble nests are known as aphr ...

with some floating plants, fiercely guarding it after the female lays down her eggs.

Relationship to humans

The cascarudo is of commercial importance in the aquarium trade industry and of minor importance as a food source. It can be kept in aquariums, with groups of more than five individuals recommended.

References

External links

Photos at Fishbase
{{DEFAULTSORT:Callichthys Callichthys Callichthys Fish of South America Fish of the Amazon basin Fish described in 1758 Taxa named by Carl Linnaeus