In fish, a suckermouth is a ventrally-oriented (inferior) mouth adapted for grazing on algae and small organisms that grow on submerged objects.
12-407: Pogonopoma Pseudorinelepis Rhinelepis Rhinelepini is a tribe of fishes in the subfamily Hypostominae of the armored suckermouth catfish family Loricariidae . This tribe is a well diagnosed monophyletic group currently containing three genera : Pogonopoma , Pseudorinelepis , and Rhinelepis . When the tribe was first described, Pogonopomoides was a valid genus, but it
24-470: A special opening on the gill cover so that the fish can breathe without using its mouth. Additionally many other fish of the order Cypriniformes have developed a sucking ability to a lesser or greater extent: In general many benthic dwelling or feeding fish will have a suckermouth feature. Many of these fishes originate from fast-moving waters, where the sucker allows the fish to 'stick' itself down without too much difficulty. Whilst all these fish have
36-493: A suckermouth as do the cypriniform algae eaters of the genus Gyrinocheilus and other genera. The 'False Siamensis' (Epalzeorhynchus sp. or Garra taeniata) also has this feature. Three genera in Mochokidae , Atopochilus , Chiloglanis , and Euchilichthys , also possess an oral sucker, formed by the lips and part of the barbels . The Loricariidae and members of the genus Gyrinocheilus are further adapted by having
48-406: A valid genus, was placed in synonymy with Pogonopoma . This genus and Rhinelepis have a sister group relationship. There are currently three recognized species in this genus: As loricariids, Pogonopoma species all exhibit a suckermouth and an at least slightly flattened ventral surface. However, unlike many loricariids, they have circular pupils, which differs from most members of
60-532: Is fairly flattened, and also has longer pectoral and pelvic fins compared to other species of the tribe Rhinelepini. The gill openings are not as large as those in Rhinelepis . Also, this species lacks long cheek odontodes and the adipose fin. P. obscurum , unlike P. wertheimeri , simultaneously lacks an adipose fin and cheek odontodes. Its dorsal fin base is also longer than of other members of this genus. Suckermouth All Loricariidae possess
72-402: Is known as carachama sin costilla , which actually means "Loricariid without ribs"; this refers to the trait that it shares with other Rhinelepini catfish; members of this tribe do not have ribs past the sixth vertebra. One of the characters that binds this group together is a large U-shaped diverticulum of the digestive tract; this is always filled with air. The first part of the diverticulum
84-411: Is modified from the esophagus and consists of thick musculature; this passes a short distance before reaching the second, main, U-shaped part of the diverticulum. In Rhinelepis and Pseudorinelepis , the diverticulum functions as an accessory respiratory organ. In Rhinelepis , the diverticulum is more attached to the abdominal wall and the interior of the diverticulum is more textured. In Pogonopoma ,
96-467: Is now a synonym of Pogonopoma . Pseudorinelepis is the most basal , and Rhinelepis and Pogonopoma are more derived sister groups . Rhinelepini species are generally medium to large-sized Loricariids. Rhinelepini species are unique among Loricariidae for having a normal, circular iris as opposed to the bilobed, omega iris . These species end to have relatively thick armor plates on their bodies. In Iquitos , Peru , Pseudorinelepis genibarbis
108-525: The Amazon area, while the distribution of the newer, more derived groups occurs in Southern Brazil, which is comparatively older. Pogonopoma Pogonopomoides Gosline, 1947 Pogonopoma is a genus of armored catfish native to rivers in south and southeast Brazil . Pogonopoma is one of three genera currently valid in the tribe Rhinelepini . Pogonopomoides , previously
120-437: The diverticulum is similar to a swim bladder and may be used as a hydrostatic organ; the first part of the diverticulum is greatly reduced and the second part is larger and has a smooth interior surface and less vascularized. The tribe Rhinelepini has an interesting biogeography and reveal information about the aquatic systems of South America . There is a split between the species that inhabit Amazon and those that inhabit
132-723: The eastern river systems. Pseudorinelepis , the most basal group, is found only in the Amazon basin. Pogonopoma , is found in the Mucuri , Paraíba do Sul , and Uruguay River systems in southeastern Brazil . Rhinelepis is found in São Francisco River and Paraná River . It is also thought to have spread through to the Paraíba by a sharing of its headwaters with the Paraná in the past, which eventually got separated into two basins. The oldest group, Pseudorinelepis , inhabits
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#1732798696415144-423: The family that have an omega iris . Pogonopoma species are heavily armored except on their abdomen (the belly in the case of loricariids), which is relatively unplated. P. wertheimeri is a cylindrically shaped loricariid. The cheek is covered in long, thin, non-evertible odontodes that form a dense patch. P. parahybae appears to be more of an intermediate between P. wertheimeri and Rhinelepis . It
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