Otocinclus

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Otocinclus
Otocinclus arnoldi (1).JPG
Otocinclus arnoldi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Siluriformes
Family: Loricariidae
Tribe: Hypoptopomatini
Genus: Otocinclus
Cope, 1871
Type species
Otocinclus vestitus
Cope, 1872

Otocinclus is a genus of catfish in the family Loricariidae native to South America, commonly known as "dwarf suckers" or "otos". This genus, like other loricariids, is characterized by rows of armour plating covering the body, as well as the underslung suckermouth. They are generally small in size; O. tapirape is the smallest of the species (2.4 cm), while O. flexilis is the biggest (5.5 cm). [1] These species have adaptations that allow them to breathe air. A duct forms at the junction between the esophagus and the stomach and expands into an enlarged, ring-like diverticulum, characteristic of this genus, which allows air-breathing. [2] Otocinclus are popular aquarium fish, and they are often purchased as algae eaters. It is difficult to breed them in captivity, and only wild caught Otocinclus are available to hobbyists. This genus is widely distributed east of the Andes of South America, throughout the lowlands from northern Venezuela to northern Argentina, but are generally absent from the Amazon and the Orinoco lowlands. [3]

Contents

Etymology

The Otocinclus name is derived from the Greek oto, meaning ear and the Latin cinclus, meaning a latticework, an allusion to the holes in the head in the region of the ear. [1]

Taxonomy

Otocinclus is the most basal genus of the tribe Hypoptopomatini of the subfamily Hypoptopomatinae. However, phylogenetic relationships are currently under study and this genus may eventually be relocated. [4] Its monophyly is supported by seven derived features. O. batmani, O. bororo, O cocama, O. huaorani, O. mariae and O. mura form a monophyletic group within this genus. [4] A monophyletic group is also formed by O. flexilis, O. mimulus and O. xakriaba, which all share mimicry as a synapomorphy. [3]

Species

There are currently 19 recognized species in this genus:

Macrotocinclus affinus was considered to be a member of Otocinclus until it was moved to its own monotypic genus, Macrotocinclus . [7] The name Otocinclus affinus is still used in the aquarium trade, however it actually refers to members of O. vittatus, O. vestitus and O. macrospilus. and O. huaorani.

Ecology

Species of this genus are diurnal and generally are found in small streams or along the margins of larger rivers, clinging to substrates using their suckermouth. The fish of this genus primarily feed on algae or aufwuchs on roots, stones, macrophytes and broad-leaved grasses. [3] They inhabit well-oxygenated, moderate- to slow-flowing environments, often near river banks. They are found near the surface of the water, but are often associated with vegetation or other structures. [4] They lay adhesive eggs and do not guard them; this is in contrast to many other loricariids where the male builds a nest and guards the eggs. [8] These fish live in shoals or schools. [3] Otocinclus are able to breathe air. Prior to surfacing, they will release air through their gills and mouth. Upon returning to the bottom, the fish do not need to pump their buccal cavities, indicating they are absorbing oxygen from the swallowed air. [2]

O. flexilis, O. mimulus and O. xakriaba are considered to be Batesian mimics of certain Corydoras species ( C. diphyes , C. garbei , C. nattereri and C. paleatus , respectively). These Corydoras species have bony plates of armor and strong spines as defenses, making them less palatable; by mimicking these species in size and coloration, Otocinclus spp. avoid predation. [3]

Related Research Articles

<i>Ancistrus</i> Genus of fishes

Ancistrus is a genus of nocturnal freshwater fish in the family Loricariidae of order Siluriformes, native to freshwater habitats in South America and Panama. Fish of this genus are common in the aquarium trade where they are known as bushynose or bristlenose catfish. In the aquarium hobby they are often referred to as bushynose or bristlenose plecos instead, but this may lead to confusion as "pleco" usually is used for Hypostomus plecostomus and its allies and is often used as a catchall term for any loricariids remotely resembling that species.

<span class="mw-page-title-main">Loricariidae</span> Largest family of catfish

Loricariidae is the largest family of catfish, 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 noted for the bony plates covering their bodies and their suckermouths. Several genera are sold as "plecos", notably the suckermouth catfish, Hypostomus plecostomus, and are popular as aquarium fish.

<i>Corydoras</i> Genus of fishes

Corydoras is a genus of freshwater catfish in the family Callichthyidae and subfamily Corydoradinae. The species usually have more restricted areas of endemism than other callichthyids, but the area of distribution of the entire genus almost equals the area of distribution of the family, except for Panama where Corydoras is not present. Corydoras species are distributed in South America where they can be found from the east of the Andes to the Atlantic coast, from Trinidad to the Río de la Plata drainage in northern Argentina. Species assigned to Corydoras display a broad diversity of body shapes and coloration. Corydoras are small fish, ranging from 2.5 to 12 cm in SL., and are protected from predators by their body armor and by their sharp, typically venomous spines.

<span class="mw-page-title-main">Zebra oto</span> Species of fish

The zebra oto or tiger oto is a fish of the genus Otocinclus of the family Loricariidae that originates from Peru.

The golden otocinclus is one of the smallest known suckermouth catfish, often called a 'dwarf oto'. Endemic to Southeast Brazil, this herbivorous, rheophilic, bottom-feeder only grows to around 4 cm (1.6 in) in length. The close relatives of this small fish are often used for the purpose of controlling algae in small home aquariums, under the name Otocinclus affinis. In reality, they belong to the species O. vittatus, O. vestitus and O. macrospilus and O. huaorani. The real M. affinis is not present in the aquarium hobby.

<span class="mw-page-title-main">Loricarioidea</span> Superfamily of fishes

Loricarioidea is a superfamily of catfishes. It contains the six families Trichomycteridae, Nematogenyiidae, Callichthyidae, Scoloplacidae, Astroblepidae, and Loricariidae. Some schemes also include Amphiliidae. This superfamily, including Amphiliidae, includes about 156 genera and 1,187 species.

<i>Hemiancistrus</i> Genus of fishes

Hemiancistrus is a genus of suckermouth armored catfishes. These species are native to South America. The taxonomy of this genus is complex and unclear, and major work has to be done. Many of these fish are popular aquarium fish.

Lithogenes is a genus of South American catfish of the family Loricariidae. It is the only genus within the subfamily Lithogeneinae.

Pogonopoma is a genus of armored catfish native to rivers in south and southeast Brazil.

<span class="mw-page-title-main">Loricariinae</span> Subfamily of fishes

Loricariinae is a subfamily of the family Loricariidae of catfish. This subfamily is divided into two tribes and about 30 genera. They are mainly native to freshwater habitats in South America, but there are also several species in Panama and a single (Fonchiiichthys) in Costa Rica.

<span class="mw-page-title-main">Hypoptopomatinae</span> Subfamily of fishes

The Hypoptopomatinae are a subfamily of catfishes of the family Loricariidae, composed of 17 genera and approximately 80 species. This subfamily represents about one-tenth of all loricariid species.

Pareiorhaphis is a genus of catfish in the family Loricariidae native to South America. This genus can be readily distinguished from other neoplecostomines by the unique combination of having fleshy lobes on lateral margins of head ornamented with hypertrophied odontodes on nuptial males, caudal peduncle ovoid in cross section, abdomen usually naked, dorsal fin spinelet ovoid and adipose fin usually present. The color pattern is usually dark brown and mottled with the abdomen white. Most species in to Pareiorhaphis were originally described in Hemipsilichthys. In 1918, Alípio de Miranda-Ribeiro proposed the new genus Pareiorhaphis. Whether Pareiorhaphis is monophyletic or not is currently unknown.

<i>Parotocinclus</i> Genus of fishes

Parotocinclus is a genus of fish in the family Loricariidae native to South America. This genus is distributed through almost all hydrographic systems in South America from the Guyana Shield drainages and Amazon Shield tributaries to the coastal drainages of eastern and southeastern Brazil, including the rio São Francisco basin. Most species have the caudal peduncle oval in cross section. It has been found that Characidium species may interact with P. maculicauda. The small Characidium will follow grazing P. maculicauda, which release particulate matter dislodged from the catfish's foraging.

Otocinclus xakriaba is a species of suckermouth catfish native to the São Francisco river basin in South America. This species reaches a maximum length of 3.1 centimetres (1.2 in) (SL).

Nannoplecostomus eleonorae is a species of armored catfish known only from the upper Rio Tocantins basin in the Brazilian state of Goiás. This species grows to a length of 2.22 centimetres (0.87 in) SL. This species is the only known member of its genus and the smallest loricariid catfish known.

Otocinclus mimulus is a species of armoured catfish found in small tributaries of the Monday river, itself a tributary of the Paraná river.

Pterygoplichthys anisitsi also known as the Paraná sailfin catfish, southern sailfin catfish, is a species of catfish in the family Loricariidae. Its natural range is the middle Paraná and Uruguay River basins of south-central South America, but it has been introduced to North America and South Asia, probably via the pet trade. Like other loricariid catfishes, Pterygoplichthys anisitsi has a ventral mouth modified into a sucking disk and a body covered in bony plates. The species typically has a dark and white spotted body pattern, although some individuals are very dark with few spots. It reaches 55 cm in total length and can weigh up to at least 2.3 kg.

Corydoras diphyes is a tropical freshwater fish belonging to the Corydoradinae sub-family of the family Callichthyidae. It originates in inland waters in South America. Corydoras diphyes is restricted to tributaries of the río Monday and the río Acaray, and right bank tributaries of the río Paraná in Paraguay.

Scott Allen Schaefer is an American ichthyologist working at the American Museum of Natural History as the dean of science for collections, exhibitions, and the public understanding of science; he serves as the curator-in-charge, in the department of ichthyology, within the division of vertebrate zoology.

<i>Otocinclus macrospilus</i> Species of catfish

Otocinclus macrospilus is a species of catfish in the family Loricariidae. It is native to South America, where it is known from the Amazon River basin. The species reaches 3.5 cm SL and is found in the aquarium trade, where it is sometimes referred to as the common otocinclus or dwarf otocinclus, both of which can lead to confusion with other Otocinclus and Macrotocinclus species.

References

  1. 1 2 Froese, Rainer and Pauly, Daniel, eds. (2016). Species of Otocinclus in FishBase . June 2016 version.
  2. 1 2 Armbruster, J.W. (1998): Modifications of the Digestive Tract for Holding Air in Loricariid and Scoloplacid Catfishes. Copeia, 1998 (3): 663–675.
  3. 1 2 3 4 5 Axenrot, T.E. & Kullander, S.O. (2003): Corydoras diphyes (Siluriformes: Callichthyidae) and Otocinclus mimulus (Siluriformes: Loricariidae), two new species of catfishes from Paraguay, a case of mimetic association. Archived 2009-02-05 at the Wayback Machine Ichthyological Exploration of Freshwaters, 14 (3): 249–272.
  4. 1 2 3 4 Lehmann, A., P. (2006): Otocinclus batmani, a new species of hypoptopomatine catfish (Siluriformes: Loricariidae) from Colombia and Peru. Neotropical Ichthyology, 4 (4): 379–383.
  5. Ribeiro, A.C. & Lehmann, A., P. (2016): A new Otocinclus (Siluriformes: Loricariidae: Hypoptopomatinae) from the Rio Juruena Basin, central Brazil. Zootaxa, 4147 (3): 240–246.
  6. Lehmann, A., P., Mayer, F. & Reis, R.E. (2010): A New Species of Otocinclus (Siluriformes: Loricariidae) from the Rio Madeira Drainage, Brazil. Copeia, 2010 (4): 635–639.
  7. Macrotocinclus Isbrücker & Seidel, 2001 in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset doi : 10.15468/39omei accessed via GBIF.org on 2020-12-16.
  8. Fenner, R. "The Ideal Algae Eater? The Littlest South American Suckermouth Catfishes, Genus Otocinclus".