Pterygoplichthyini | |
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Pterygoplichthys sp. | |
Scientific classification
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Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Siluriformes |
Family: | Loricariidae |
Subfamily: | Hypostominae |
Tribe: |
Pterygoplichthyini Armbruster, 2004 |
Genera | |
Pterygoplichthyini is a tribe of catfishes ( order Siluriformes) of the family Loricariidae. It includes two genera, Pterygoplichthys and the currently undescribed genus referred to as the Hemiancistrus annectens group, [1] This group was earlier misspelled as Pterygoplichthini. [1] Pterygoplichthyines are known from nearly the entire range of loricariids except for the Guyanas and coastal streams in southeastern Brazil. [1] although later work by the same authority, and his co-authors, placed this group among the genus Hypostomus. [2]
Pterygoplichthyini is sister to the tribe Ancistrini, which shares the derived presence of an evertible patch of plates on the cheek. [1]
Pterygoplichthys and the H. annectens group differ most obviously in the number of dorsal fin rays (7 in the H. annectens group and 9+ in Pterygoplichthys). [1] The two genera are supported as sisters by only one derived characteristic: a modified stomach that is attached to the abdominal wall by a net of connective tissue. [1]
This modified stomach allows these fish to breathe air. The stomach is vascularized. A white net of connective tissue surrounds the organ, leaving a circular area in the middle of the stomach free; this connective tissue firmly holds the stomach to the body wall and is better developed in adults. It may also function as a hydrostatic organ, allowing the fish to remain buoyant midwater. [3]