Serrasalmidae (Malabarba & Weitzman, 2003)

Mirande, Juan Marcos, 2010, Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy, Neotropical Ichthyology 8 (3), pp. 385-568 : 471-472

Node 187: Serrasalmidae (100 / 100 / 100 / 59)

Genera Acnodon Eigenmann , Catoprion Müller & Troschel , Colossoma Eigenmann & Kennedy , † Megapiranha Cione, Dahdul, Lundberg & Machado-Allison , Metynnis Cope , Mylesinus Valenciennes , Myleus Müller & Troschel , Mylossoma Eigenmann & Kennedy , Ossubtus Jégu , Piaractus , Pristobrycon Eigenmann , Pygocentrus Müller & Troschel , Pygopristis Müller & Troschel , Serrasalmus , Tometes Valenciennes , and Utiaritichthys Miranda Ribeiro.

The monophyly of this clade was proposed by Machado-Allison (1983, 1986), supported by 27 synapomorphies, and subsequently corroborated by the molecular phylogenies by Ortí et al. (1996) and Calcagnotto et al. (2005). The taxonomic level of this group has been longly debated. Géry (1977) treated it as a family, while Machado-Allison (1982, 1983, 1985, 1986) and Jégu (2003) considered this clade as a subfamily of the Characidae . According to the phylogenetic hypothesis of Calcagnotto et al. (2005), this clade should be classified as a family, as herein proposed. As only a small sample of the serrasalmids are herein analyzed, some synapomorphies could correspond to more inclusive clades.

Synapomorphies:

1. Ventral projection of lagenar capsule (3): (0> 1) extending ventrally to articulation between basioccipital and parasphenoid. Paralleled in nodes 170, 205, and 302 and in Cyphocharax spilotus and Micralestes stormsi .

2. Length of supraoccipital spine (53): (1> 0) extends posteriorly to, at least, middle length of neural complex of Weberian apparatus. Paralleled in nodes 182 and 205 and in Piabucus melanostomus and Prochilodus lineatus . Some trees: Paralleled in Brycon meeki and B. orbignyanus .

3. Teeth on inner premaxillary row (126): (1> 0) molariform.

4. Polymorphism of teeth on inner premaxillary row (131): (0> 1) present, with two medial teeth somewhat larger and usually separated from remaining ones by a gap. Paralleled in the Bryconinae .

5. Posterior directed radial striae from articular region of opercle (169): (0> 1) present. Paralleled in Prochilodus lineatus .

6. Length of medial bony ridge of opercle (170): (1> 0) 60% or greater than opercular length. Paralleled in node 210 and in Astyanax abramis , Creagrutus cf. taphorni , Hoplias cf. malabaricus , and Roeboides microlepis . Some trees: Paralleled in Acestrorhynchus pantaneiro and Salminus brasiliensis .

7. Bony lamellae between second and third basibranchials (184): (1> 0) absent. Paralleled in Attonitus ephimeros , Axelrodia lindeae , Hollandichthys multifasciatus , Hoplocharax goethei , Jupiaba scologaster , Piabucus melanostomus , Pyrrhulina australis , Rhaphiodon vulpinus , and Xenagoniates bondi .

8. Lateral base of gill rakers on first ceratobranchial (199): (0> 1) broad and laminar at least on anteriormost gill rakers. Paralleled in in nodes 166 and 177 and in Hoplias cf. malabaricus . Reversed in Agoniates anchovia .

9. Abdominal ribs on anterior caudal vertebrae (225): (0> 1) present, associated to first and occasionally second caudal vertebrae.

10. Number of dorsal pterygiophores (278): (0> 1) 12 or more. Paralleled in Characidium rachovii , Distichodus maculatus , Hoplias cf. malabaricus , and Thoracocharax stellatus .

11. Bony lamellae associated with supraneurals (282): (0> 1) wider than primary axis of supraneurals. Paralleled in Micralestes stormsi .

12. Fusion of hypural 2 to compound centrum (298): (1> 0) absent. Paralleled in nodes 174 and 184 and in Distichodus maculatus , Hemiodus cf. thayeria , and Hoplias cf. malabaricus . 13. Radii on scales (320): (1> 0) absent or reduced in number. Paralleled in the Iguanodectinae , in node 174, and in Cyphocharax spilotus , Distichodus maculatus , Markiana nigripinnis , and Phenagoniates macrolepis .

14. Median predorsal scales(325):(0> 1)leaving naked area anterior to dorsal fin. Paralleled in node 284 and in Lonchogenys ilisha .

15. Ventral serrae (326): (0> 1) present.

16. Scales covering anal-fin base (327): (0> 1) several rows covering basal third of anal fin. Paralleled in nodes 210 and 221 and in Bario steindachneri , Markiana nigripinnis , Paragoniates alburnus , Rhaphiodon vulpinus , Roeboides microlepis , and Thoracocharax stellatus .

17. Diffuse spots on flanks (346): (0> 1) present, especially in young specimens.

18. Number of 2n chromosomes (363): (0> 1) 52 or more. Paralleled in the Characinae , in node 196, and in Chalceus macrolepidotus , Hyphessobrycon herbertaxelrodi , Markiana nigripinnis , and Rhaphiodon vulpinus . Some trees: Paralleled in Hemigrammus unilineatus .

19. Number of 2n chromosomes (364): (0> 1) 54 or more. Paralleled in Rhaphiodon vulpinus .