19-478: Acnodon Catoprion Colossoma † Megapiranha Metynnis Mylesinus Myleus Myloplus Mylossoma Ossubtus Piaractus Pristobrycon Pygocentrus Pygopristis Serrasalmus Tometes Utiaritichthys The Serrasalmidae (serrasalmids) are a family of characiform fishes, recently elevated to family status. It includes more than 90 species. The name means "serrated salmon family", which refers to
38-486: A common ancestor . Typical characters of Tometes coincide with Mylesinus and Ossubtus specimen more than Myleus . It is further known that Tometes live in sympatry with other reophilic Serrasalmidae. Tometes species are also not to be mistaken with pacus , a vegetarian fish, which is often sold as a vegetarian piranha in the corresponding countries. One can easily distinguish one from another by their very different composition of their dentition. Depending on
57-678: A deep, laterally compressed body with a series of midventral abdominal spines or scutes , and a long dorsal fin (over 16 rays). Most species also possess an anteriorly directed spine just before the dorsal fin extending from a supraneural bone; exceptions include members of the genera Colossoma , Piaractus , and Mylossoma . Most serrasalmids have about 60 chromosomes , ranging from 54 to 62. Metynnis has 62 chromosomes, as does Catoprion , Pristobrycon striolatus , and Pygopristis . Serrasalmids inhabit all major and some minor Atlantic river systems in South America east of
76-433: Is a genus of serrasalmids found in South America , with three recognized species: This Characiformes -related article is a stub . You can help Misplaced Pages by expanding it . Tometes Tometes is a genus of fish in the family Serrasalmidae found in fast-flowing rivers in northern South America . Adults of all seven species in this genus are phytophagous , feeding primarily on aquatic plants in
95-459: Is a positive rheotrophism (adaptability to fast-flowing water) in the larval stage. Unlike the strictly phytophagous adults, juveniles also feed on invertebrates . Their association with Podostemaceae plants restricts their distributions, which makes them vulnerable to the loss of rapids by the introduction of hydroelectric dams. In a cultural aspect rheophilic serrasalmids (notably Tometes , Myloplus and Mylesinus ) are important in
114-584: Is relatively sparse. Most known fossils are from the Miocene , although a few unidentified forms are considered Paleocene and two reportedly date to as early as the Late Cretaceous . Fossils of a living species of Colossoma from the Miocene have been described, suggesting a very conservative history for a specialized herbivorous fish. All serrasalmine genera had originated by the middle Miocene, with
133-458: The Andes , but have been introduced to other areas. Species range from about 10°N latitude south to about 35°S latitude. The diets of the various serrasalmid fishes include seeds , fruits , leaves , and various invertebrate and vertebrate prey, as well as fish flesh, scales , and fins. To emphasize the diversity of diets, authors commonly highlight the fruit- and leaf-eating pacus and
152-403: The serrated keel running along the belly of these fish. Fish classified as Serrasalmidae are also known by these common names: pacu , piranha , and silver dollar . These common names generally designate differing dental characteristics and feeding habits. Serrasalmids are medium- to large-sized characiform fishes that reach about 1 m (3.3 ft) long, generally characterized by
171-455: The aquarium trade, and, in recent decades, dried specimens have been marketed as tourist souvenirs . Piranhas occasionally bite and sometimes injure bathers and swimmers, but serious attacks are rare and the threat to humans has been exaggerated. However, piranhas are a considerable nuisance to commercial and sport fishers because they steal bait, mutilate catch, damage nets and other gear, and may bite when handled. Acnodon Acnodon
190-473: The eastern Guiana Shield ( Trombetas , Commewijne , Mana , Maroni , Oyapock , Amapá Grande and Araguari basins), and T. makue is from the Rio Negro and Orinoco basins. These species all live in rapidly moving water with a rocky environment. A dense occurrence of Tometes larvae and juveniles in rapids around Podostemaceae plants, the main food source of adult Tometes , suggests that there
209-423: The exact species, the maximum length of Tometes is between 28.3 and 91.1 cm (0.9–3.0 ft). They can weigh more than 5 kg (11 lb). The body color is generally gray or silvery, showing a brighter color at the bottom side. Their name was given due to their incisiform teeth, which are thicker and lower than in the other related genera. Also the teeth are placed side by side, are weakly attached to
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#1732779632895228-416: The family Podostemaceae . The genus name Tometes was coined in 1850 by Valenciennes in reference to the incisiform teeth. When the type species of the genus, T. trilobatus , was described in 1850, it was placed in synonym with Myleus setiger , the type species of the genus Myleus , which is why Tometes and Myleus were considered to be the same genus for a long time. It was just later that
247-425: The highly carnivorous piranhas . Most in the family other than piranhas are primarily herbivorous . In contrast, piranhas have been long believed to be strict carnivores . Many species change diets depending on age and resource availability. The primarily carnivorous piranha group comprises the genera Catoprion , Pristobrycon , Pygocentrus , Pygopristis and Serrasalmus , but based on phylogeny also
266-517: The jaw and are primarily used for cutting leaves. Sexually mature male of Tometes differ from females by an additional anal-fin lobe, an elongated dorsal fin or a red pattern on the body. T. ancylorhynchus , T. kranponhah and T. siderocarajensis are found in clearwater rivers that originate in the Brazilian Shield ( Xingu and Tocantins — Araguaia basins), T. camunani , T. lebaili and T. trilobatus are found in rivers of
285-681: The mainly herbivorous (although with omnivorous tendencies) Metynnis . The remaining primarily herbivorous species can be divided into two groups based on ecology and, to some extent, phylogeny: Colossoma , Mylossoma and Piaractus are mainly found in relatively slow-moving waters, and feed extensively on fruits, nuts and seeds, playing an important role as seed dispersers . Mylesinus , Myleus , Ossubtus , Tometes and Utiaritichthys are found in fast-flowing sections of rivers, and mainly feed on aquatic plants, especially Podostemaceae . Myloplus mostly feed on plant material and some of its species are phylogenetically related with
304-477: The ongoing classification of these fish is difficult and often contentious, with ichthyologists basing ranks according to characteristics that may overlap irregularly (see Cladistics ). Ultimately, classifications can be rather arbitrary. Despite this, the Serrasalmidae are relatively well understood, and agreement is wide on the genera and species included. The fossil record, particularly for piranhas,
323-490: The possible exception of three of the four piranha genera ( Pygocentrus , Pristobrycon , and Serrasalmus ). Many serrasalmids are in demand as aquarium ornamentals, and several pacus, such as Piaractus and Colossoma , are economically important to commercial fisheries and aquaculture . Piranhas are generally less valued, although they are commonly consumed by subsistence fishers and frequently sold for food in local markets. A few piranha species occasionally appear in
342-515: The previous group, but this genus includes species of both slow and fast-flowing waters. The Serrasalmidae were recently classified as a subfamily of the Characidae . Their relationship to other characiforms has yet to be determined. The taxonomy and systematics of piranhas and their relatives are complicated and much remains unsettled. Consequently, both species identification and phylogenetic placement of many taxa are problematic. However,
361-505: The two genera were revalitated and other specimen could be categorized in the genus Tometes . Even today the taxonomic classification of the Serrasalmidae is not an easy task. Many names are placed in synonymy due to a lack of information and insufficient data bases. It was not long ago when it was discovered that Tometes and Myleus are two different genera but that Tometes , Myleus , Mylesinus and Ossubtus share
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