''Loricariichthys'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

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 ...

es ( order Siluriformes) of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Loricariidae The Loricariidae is the largest family of catfish (order Siluriformes), with 92 genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South America. These fish are not ...

Taxonomy

This genus is part of the ''Loricariichthys'' group within the subfamily

Loricariinae Loricariinae is a subfamily of the family Loricariidae of catfish (order Siluriformes). This subfamily is divided into two tribe (biology), tribes and about 30 genus, genera. They are mainly native to freshwater habitats in South America, but the ...

; this group also includes the genera '' Furcodontichthys'', ''

Hemiodontichthys ''Hemiodontichthys acipenserinus'' is the only species of the monotypic genus ''Hemiodontichthys'', a genus of the family Loricariidae of catfish ( order Siluriformes). Taxonomy This taxon is often compared with the morphologically similar '' ...

'', '' Limatulichthys'', and '' Pseudoloricaria''. ''Loricariichthys'' seems to be intermediate between ''Limatulichthys'' and ''Pseudoloricaria'' on one hand, and ''Furcodontichthys'' and ''Hemiodontichthys'' on the other. Although this genus is well diagnosed, the species are very similar and difficult to identify.

Species

There are currently 18 recognized species in this genus: * '' Loricariichthys acutus'' (

Valenciennes Valenciennes (, also , , ; nl, label=also Dutch, Valencijn; pcd, Valincyinnes or ; la, Valentianae) is a commune in the Nord department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced a ...

, 1840) * '' Loricariichthys anus'' (

, 1835) * '' Loricariichthys brunneus'' (

Hancock Hancock may refer to: Places in the United States * Hancock, Iowa * Hancock, Maine * Hancock, Maryland * Hancock, Massachusetts * Hancock, Michigan * Hancock, Minnesota * Hancock, Missouri * Hancock, New Hampshire ** Hancock (CDP), New Hampshir ...

Regan The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri'' ...

, 1913

Distribution

''Loricariichthys'' is distributed in most major freshwater drainages east of the

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

and north of

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

. ''Loricariichthys'' is widely distributed in the Amazon basin, the Paraná system, and coastal rivers of the Guiana and Brazilian Shields.

Description

An accessory

respiration organ The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gr ...

, consisting of a double respiratory purse connected to the distal end of the

esophagus The esophagus ( American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to ...

, is present in a number of species of ''Loricariichthys''. The lower lip of immature males and females has two thick, cushionlike structures, which are covered with small

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

e and have irregular fringes along the posterior edge. However, in

nuptial A wedding is a ceremony where two people are united in marriage. Wedding traditions and customs vary greatly between cultures, ethnic groups, religions, countries, and social classes. Most wedding ceremonies involve an exchange of marriage vo ...

males of ''Loricariichthys'', the cushionlike structures on the lower lip recede or even disappear, and the lip becomes wider and longer and becomes smooth or covered with minute papillae. Males use this enlarged lower lip to clasp and carry a cluster of developing

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s. This method of carrying eggs is possibly a strategy to protect the eggs from

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

, since these fishes commonly live in exposed sandy- or muddy-bottomed environments devoid of places to hide. A

diploid number Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respective ...

of 2n = 56 has been reported for two species characterized. A ZZ/ZW sex chromosome system was also reported for ''L. platymetopon''.

Ecology

These species occur in a large diversity of habitat over sandy and muddy bottoms. Like other members of the ''Loricariichthys'' group, ''Loricariichthys'' species are lip brooders. The male holds the clutch of eggs in a large membranous extension of the lower lip.

References

{{Taxonbar, from=Q3766327 Loricariini Fish of South America Fish of the Amazon basin Catfish genera Taxa named by Pieter Bleeker Freshwater fish genera