|Boeseman's rainbowfish, Melanotaenia boesemani, red variety|
D. E. Rosen, 1966
The Atheriniformes, also known as the silversides, are an order of ray-finned fishes that includes the Old World silversides and several less-familiar families, including the unusual Phallostethidae. The order includes at least 354 species. They are found worldwide in tropical and temperate marine and freshwater environments.
Atheriniformes are generally elongated and silvery in colour, although exceptions do exist. They are typically small fish, with the largest being the jacksmelt, with a head-body length of 44 cm (17 in), and the smallest species, such as the Bangkok minnow, being only 2 cm (0.79 in) in adult length.
Members of the order usually have two dorsal fins, the first with flexible spines, and an anal fin with one spine at the front. The lateral line is typically weak or absent. Atheriniform larvae share several characteristics; the gut is unusually short, a single row of melanophores occurs along the back, and the fin rays do not become evident until some time after hatching. They scatter their eggs widely, with most species attaching them to aquatic plants.
Classification of the atheriniformes is uncertain, with the best evidence for monophyly in the larval characteristics mentioned below. Their closest relatives are thought to be the Cyprinodontiformes.
Nelson 2016 recognises the infraseries Atherinomorpha, part of the sub series Ovalentaria which includes the orders Atheriniformes, Beloniformes, and Cyprinodontiformes, citing the larval characteristics and supporting molecular studies of these taxa as support for monophyly of this grouping. The sister taxon to the Atherinomorpha appears to be the Mugiliformes.
Following Nelson (2006), the family Melanotaeniidae includes the subfamilies Bedotiinae, Melanotaeniinae, Pseudomugilinae, and Telmatherininae, to demonstrate their monophyly. However, in a 2004 study, a different classification scheme classifies the families Bedotiidae, Melanotaeniidae, and Pseudomugilidae (also include Telmatherinine genera) in a suborder Melanotaenioidei. Thus, the number of families in Atheriniformes varies from author to author.
Nelson 2016 classifies the families as follows:
- Order Atheriniformes
- Suborder Atherinopsoidei
- Suborder Atherinoidei
Timeline of genera
- J. S. Nelson; T. C. Grande; M. V. H. Wilson (2016). Fishes of the World (5th ed.). Wiley. p. 354. ISBN 978-1-118-34233-6.
- Allen, Gerald R. (1998). Paxton, J.R.; Eschmeyer, W.N. (eds.). Encyclopedia of Fishes. San Diego: Academic Press. pp. 153–156. ISBN 0-12-547665-5.
- Nelson, Joseph S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 0-471-25031-7.
- Sparks, John S.; Smith, W. Leo (2004). "Phylogeny and biogeography of the Malagasy and Australasian rainbowfishes (Teleostei: Melanotaenioidei): Gondwanan vicariance and evolution in freshwater" (PDF). Molecular Phylogenetics and Evolution. 33 (3): 719–734. doi:10.1016/j.ympev.2004.07.002. PMID 15522799. Retrieved 2009-06-22.