Loricarioidei is a

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

catfish Catfish (or catfishes; order (biology), order Siluriformes or Nematognathi) are a diverse group of ray-finned fish. Catfish are common name, named for their prominent barbel (anatomy), barbels, which resemble a cat's whiskers, though not ...

es (

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Siluriformes). It contains the six

families Family (from ) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictability, structure, and safety as ...

Trichomycteridae, Nematogenyiidae, Callichthyidae, Scoloplacidae,

Astroblepidae ''Astroblepus'' is a genus of fish in the family (biology), family Astroblepidae found in South America and Panama. This genus is the only member of its family. These catfishes are primarily found in torrential streams in the Andes, Andean area. ...

, and

Loricariidae Loricariidae is the largest family (biology), family of catfish (order Siluriformes), with over 90 genus, genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South A ...

. Some schemes also include

Amphiliidae The loach catfishes are a family, Amphiliidae, of catfishes (order Siluriformes). They are widespread in tropical Africa, but are most common in streams at high elevations; most species are able to cling to rocks in fast-flowing streams. The 13 g ...

. This superfamily, including Amphiliidae, includes about 156

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

and 1,187

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

Taxonomy

Loricarioidea was previously considered a part of Siluroidei, a clade of all catfishes excluding Diplomystidae. In Nelson, 2006, this grouping is

sister A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to ref ...

to the superfamily Sisoroidea. However, in a recent molecular analysis, it was determined that the suborder Loricarioidei (not including Amphiliidae) is sister to a group including Diplomystidae and Siluroidei. Amphiliidae, in this analysis, was found to be much more closely related to Mochokidae or

Malapteruridae Electric catfish or Malapteruridae is a family of catfishes (order Siluriformes). This family includes two genera, '' Malapterurus'' and '' Paradoxoglanis'', with 21 species. Several species of this family have the ability to generate electricit ...

. It is disputed whether Loricarioidea or Diplomystidae are the most basal group of catfish, with molecular studies favoring the former while morphological studies favor the latter. The earliest known definitive loricaroid is the callichthyid '' Corydoras revelatus'' from the

Late Paleocene The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Serie ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. Molecular estimates suggest that the main radiation of the superfamily occurred during the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

. The putative

Cenomanian The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...

member '' Afrocascudo'', discovered from the

age of the

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

(

Kem Kem Group The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group (stratigraphy), group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two ...

), was initially described as the earliest loricariid catfish in 2024, which may extend the

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

(and Siluriformes as a whole). However, this taxon might represent a juvenile obaichthyid lepisosteiform, possibly a junior synonym of ''Obaichthys'', though this has been disputed based on the complete ossification of the bones indicating full maturity and the absence of important holostean characters. Loricarioidea is currently diagnosed by the derived presence of a reduced

gas bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled organ in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift via swimming, ...

, encapsulated in expansions of the parapophysis of the first

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e, and of

odontode Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They consist of a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to t ...

s, small dermal denticles. Amphiliidae is the most basal group in Loricarioidea. In some older sources, Amphiliidae is not even included in this classification. Based on morphologically evidence, Trichomycteridae and Nematogenyiidae diverge first; these two families are probably sister groups. This relationship was neither supported nor rejected by molecular evidence. Next, the order of divergence is probably Callichthyidae, then Scoloplacidae, and then Astroblepidae and Loricariidae. A trend in increasingly complex jaw morphology can be seen in this superfamily, which may have allowed for the great diversification of the Loricariidae, which have the most advanced jaws.

Distribution and habitat

These fish are found in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

habitats in the

Neotropics The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeog ...

, inhabiting

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

, and

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

. Most species inhabit stream habitats or pools; water in these habitats tends to move relatively quickly. Loricariids and Astroblepids have adapted to this with

suckermouth In fish, a suckermouth is a ventrally-oriented (inferior) mouth adapted for grazing on algae and small organisms that grow on submerged objects. All Loricariidae possess a suckermouth as do the cypriniform algae eaters of the genus '' Gyrinocheilu ...

s that allow them to cling to surfaces. Astroblepids even have the ability to climb up waterfalls.

Description

Like other catfish, loricarioidean catfish tend to have whiskers (except within the family Loricariidae). Fish in this group can be naked or, in the case of Callichthyids, Scoloplacids, and Loricariids, armored with bony plates. Most loricarioid species are depressed (flattened) in body shape, though Callichthyids tend to be more compressed (thin). Loricarioidea is defined by two characters. First, they have a unique, encapsulated

. Also, they have

integumentary The integumentary system is the set of organs forming the outermost layer of an animal's body. It comprises the skin and its appendages, which act as a physical barrier between the external environment and the internal environment that it serves ...

teeth called odontodes on their body and fin rays. In Loricariids, these odontodes on their

gill cover The operculum is a series of bones found in bony fish and Chimaera, chimaeras that serves as a facial support structure and a protective covering for the gills; it is also used for respiration and feeding. Anatomy The opercular series contain ...

can be extended outwards. Astroblepids may use their odontodes as a sensory organ.

Ecology

Loricarioidea is a very diverse

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

group. These fish exhibit a wide range of morphologies and occupy many different

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s and

trophic level The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the ...

s. This group includes

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

omnivore An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...

s, and even

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s ( candirú) and wood-eating species ('' Panaque''). Loricariidae is by far the most successful and diverse family with approximately 700 species (and new species being discovered each year), and is the most species-rich family in the entire order.

References

{{Taxonbar, from1=Q59571362, from2=Q1651246 Siluriformes Taxa named by Constantine Samuel Rafinesque Fauna of the Neotropical realm Ray-finned fish suborders