Order

Characiformes

  Class

Actinopterygii

No. in FishBase

Genera : 145 | Species : 1112 Eschmeyer's Catalog of Fishes

  Environment

Fresh : Yes | Brackish : No | Marine : No

  Division

Primary freshwater

  Aquarium

many

  First Fossil Record

upper   Tertiary   upper   Miocene

  Remark

Species belonging to this family occur in southwestern Texas, Mexico, Central and South America. Characids are a large and diversified family. Adipose fin may be present or lacking. Genera Astyanax and Deuterodon with few species having an anteriorly directed spinelike process, protruding externally from the pelvic bone. Some are large species; many are under 3 cm with the smallest reaching a maximum size of about 13 mm. A comprehensive phylogenetic study is needed. The potentially dangerous Amazon piranhas (Serrasalmus and Pygocentrus) belong to this group as well as the South American tetras, and a blind cave fish from Mexico (Astyanax mexicanus). The African tetras are recognized in the separate family Alestiidae, following Eschmeyer 1998 (Ref. 26282). Glandulocaudinae: Fishes of the subfamily Glandulocaudinae have the following characteristics: In sexually mature males glandulocaudines bear a basal caudal-fin organ that is apparently pheromone in nature. This organ may consist of modified caudal-fin rays; modified caudal-fin scales, a derived hypural fan, and/or modified caudal-fin musculature. In species of some tribes and genera two to all of these derived features may be present. In males almost always some kind of derived glandular cells are present in association with large derived caudal-fin scales and/or modified fin rays. All species are inseminating in that the female is inseminated by the male and retains live sperm cells in her ovary, sometimes at least for many months. No fertilization of the oocytes takes place in the ovaries and presumably fertilization takes place when the eggs and sperm cells are shed at the same time. All species have elongate sperm cell bodies (nuclei) and, at least for the many species and genera for which current information is available, have sperm cells with an elongate cytoplasmic collar binding the flagellum to the elongate nucleus at least at some stage of spermiogenesis. There is one other inseminating group of characids, the tribe Compsurini of the subfamily Cheirodontinae has inseminating species and also often complex caudal organs in the male. These caudal organs are structured differently than those found in the Glandulocaudinae and the histology and fine structure of the sperm cells of the Compsurini are not structured the same way as in the glandulocaudines. Furthermore there is evidence that the Compsurini forms a derived clade within the Cheirodontinae. See Burns et al. (1995), Burns et al. (1997), Burns, et al. (1998), Burns et al. (2000), Malabarba (1998), Menezes & Weitzman (1990), Weitzman & Fink (1985), Weitzman et al. (1994), and Weitzman & Menezes (1998). The Glandulocaudinae is a morphologically diverse characid group consisting of 19 genera divided among seven tribes, each derived in a different way. The number of valid species currently recognized is 50. Most glandulocaudine fishes are relatively small, between about 30 and 60 millimeters in standard length, but some are considerably smaller, between about 11 and 30 millimeters in standard length when mature. See Weitzman & Fink (1985), Weitzman et al. (1994), and Weitzman & Menezes (1998). Glandulocaudine species are found almost throughout Central and South America, from Costa Rica in the north, southward to northern Argentina in the south. They are found in every country, including Trinidad, except Chile. The ecology and life history of glandulocaudines is complex, but so far little studied. Many occur in small to modest sized streams tributary to larger rivers such as the Amazon, Orinoco and Paraguay Rivers. Nearly all glandulocaudines are tropical in distribution with a few being subtropical and are known from coastal streams of Central and South America tributary to the Atlantic and Pacific Oceans and the Caribbean Sea. A few species are known from elevations as high as about 500 to 600 meters, but most occur at elevations considerably below that, down to sea level. Some species are confined to acid black rainforest waters with an acidic pH, others are found in neutral to somewhat alkaline waters that are clear or seasonally turbid due to sediment load. A few species are adapted to both kinds of waters. No species are known from brackish waters of coastal lagoons or river mouths under the influence of tides. The courtship behaviors of those species and genera that have been studied in detail using scientific procedures have been described as having complicated courtship procedures preceeding insemination. Aquarists have published many articles about the behavior of glandulocaudines maintained in aquaria during the last 90 years. These articles describe in varying detail the complex courtship activities of many glandulocaudine species and genera. This literature was last evaluated by Nelson (1964). Personal observations and see also Azevedo et al. (2000), Nelson (1964a, b, & c), Weitzman & Fink (1985), Weitzman (1987), Weitzman et al. (1994). Although 50 species are currently recognized, there are many undescribed species represented by population samples in museums that await descriptions. Each of the seven tribes appears monophyletic although additional studies are needed to confirm this for a few of these tribes. On the other hand the validity of the monophyly of the subfamily needs much further investigation. A few outgroup inseminating characids lack a caudal organ, but have some of the other glandulocaudine synapomorphies that were reported recently by Weitzman & Menezes (1998). It may well be that at least some of the glandulocaudine tribes are independently derived from plesiomorphic extinct relatives of these outgroup characids such as the species of Brittanichthys, some species of Knodus and Attonitus. See Burns et al. (2000). Members of this subfamily form food for larger fishes that are important for both commercial and subsistence reasons in the rivers of Central and South America. Several species are moderately important for the aquarium trade and are exported especially from Brazil and Venezuela. The Iguanodectinae is a small characid subfamily composed of 11 valid species in 2 genera, Iguanodectes Cope and Piabucus Oken. The subfamily is characterized by elongated fishes, with contracted base multicuspidated teeth, gill-membranes united and free from the isthmus, posterior end of the maxilla anterior to the eye, dorsal-fin origin posterior to the middle of the body (at middle of the body in Iguanodectes geisleri), and anal fin long (except for I. geisleri). Moreover, some characters of the internal morphology are also diagnostic, such as, the presence of a process on the internal face of the dentary, the first proximal anal-fin pterygiophore expanded and backward recurved (except in I. geisleri), and the anterior portion of the posterior chamber of the swimbladder thinner than its posterior portion. The genus Piabucus distinguishes from Iguanodectes by the presence of a long pectoral fin, and a well-developed pectoral keel. The subfamily is distributed in the Amazon (including its main tributaries), Orinoco, Paraguay, and Tocantins river basins, as well as the costal drainages from the Golfo de Pária (Venezuela) to immediately south of the mouth of the Amazon river (including rio Capim basin). The group is relatively well studied taxonomically (Böhlke,1954; Géry, 1970 and 1993; Vari, 1977), although some species remain to be described. Despite of some characters proposed as supporting the monophyly of the Iguanodectinae (Vari, 1977), the phylogenetic relationships of the Iguanodectinae with other groups of the Characiformes are still very tentative (Lucena, 1993), and none is known about the phylogenetic relationships between its species. Iguanodectes species are probably primarily herbivorous, feeding occasionally on allocthonous insects (Knöppel, 1970; Goulding et al. 1988; pers. obs.). Besides that, little information is known from their ecology. Some of its species are used as ornamental fishes. Note that Characidiinae, and Crenuchus and Poecilocharax are gathered in Crenuchidae, the two latter as the subfamily Crenuchinae since Buckup (1998: Ref. 040622) and in Buckup (2003: Ref. 37059). The description above

  Etymology

Greek charax, -akos = a marine fish without identification ( Ref. 45335).

  Reproductive guild

mixed

  Typical activity level

normal

  Main Ref

Nelson, J.S. 1994

  Coordinator

  Deep Fin Classification

Osteichthyes | Actinopterygii | Actinopteri | Neopterygii | Teleostei | Osteoglossocephalai | Clupeocephala | Otomorpha | Ostariophysi | Otophysa | Characiphysae | Characiformes | Characoidei | Characidae