Paralithoxus is a genus of suckermouth armored catfishes native to tropical South America.
| Paralithoxus | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Siluriformes |
| Family: | Loricariidae |
| Subfamily: | Hypostominae |
| Genus: | Paralithoxus Boeseman, 1982 |
| Type species | |
| Paralithoxus bovallii (Regan, 1906)
| |
Species
editThere are currently nine recognized species in this genus:[1]
- Paralithoxus boujardi So. Muller & Isbrücker, 1993
- Paralithoxus bovallii (Regan, 1906)
- Paralithoxus jariensis (Silva, Covain, Oliveira & Roxo, 2017)
- Paralithoxus mocidade Rapp-Py-Daniel, Oliveira, Bastos, Ito, Zuanon & Briglia-Ferreira, 2019[2]
- Paralithoxus pallidimaculatus Boeseman, 1982
- Paralithoxus planquettei Boeseman, 1982
- Paralithoxus raso (Silva, Covain, Oliveira & Roxo, 2017)
- Paralithoxus stocki Nijssen & Isbrücker, 1990
- Paralithoxus surinamensis Boeseman, 1982
Distribution
editParalithoxus range from the Oyapock drainage along the border between Brazil and French Guiana, through Suriname west to the Tacutu River along the border between Guyana and Brazil and south to the Uatama and Trombetas rivers of Brazil.[3]
Description
editParalithoxus contains some of the most dorsoventrally flattened fishes in the world.[4] They can be distinguished from most loricariids by having a round instead of oval lower lip. The lower lip is large and round as in Exastilithoxus with the edge sometimes frilled, but not with the barbels seen in Exastilithoxus.[4]
Paralithoxus species have a unique, enlarged, thin-walled stomach from which the intestine exits dorsally.[4] The stomach is expanded, thin-walled, and clear and is used in breathing air. A thin, clear tube exits the main body of the stomach anterodorsally, terminating at the pylorus just anterior to the posterior extent of the stomach. The intestine tends to have less coils than other members of Ancistrini. The expanded stomach is slightly larger in males; this is due to the males having more space due to a difference in the relative size of the gonads.[5]
Colouration in Paralithoxus species is typically slate gray to tan with a few lighter markings on the body; there are occasionally bands in the pectoral and caudal fins. The ventral surface ranges from white to slightly lighter than the sides. The abdomen is naked (scaleless and unplated). The caudal fin is slightly forked.[4]
Breeding males develop extremely long odontodes on the leading edge of the pectoral fin spine.[4]
Ecology
editParalithoxus species are rheophilic, meaning they prefer to inhabit fast-moving water.[3] Paralithoxus is said to inhabit both rivulets and medium-sized creeks. Paralithoxus have been collected from riffles on the main-stem Essequibo River in Guyana. These peripheral habitats are among the first parts of the river to dry and the respiratory stomach may have evolved to handle this periodic drying.[4] The flattened morphology suggests that Paralithoxus species live under rocks.[4]
Paralithoxus have a unique air-holding stomach. The large size and small number of eggs suggest that parental care is well developed, but nothing is known of the breeding habits of Paralithoxus.[5]
References
edit- ^ Froese, Rainer; Pauly, Daniel (eds.). "Species in genus Paralithoxus". FishBase. December 2011 version.
- ^ Lúcia H Rapp Py-Daniel; Andreza S. Oliveira; Douglas Bastos; Priscila Madoka Miyake Ito; Jansen Alfredo Sampaio Zuanon; Romério Briglia (January 2019). "A new species of Paralithoxus (Siluriformes: Loricariidae: Ancistrini) from the highlands of Serra da Mocidade, Roraima State, Brazilian Amazon". Neotropical Ichthyology. 17 (4). doi:10.1590/1982-0224-20190041.
- ^ a b Lujan, Nathan K. (2008). "Description of a new Lithoxus (Siluriformes: Loricariidae) from the Guayana Highlands with a discussion of Guiana Shield biogeography". Neotropical Ichthyology. 6 (3): 413–418. doi:10.1590/S1679-62252008000300014.
- ^ a b c d e f g Armbruster, Jonathan W. "Lithoxus Eigenmann, 1910". Retrieved 2007-07-24.
- ^ a b Jonathan W. Armbruster (3 August 1998). "Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes". Copeia. 1998 (3). American Society of Ichthyologists and Herpetologists (ASIH): 663–675. doi:10.2307/1447796. JSTOR 1447796.