Piabucus melanostomus, Holmberg, 1891

Autapomorphies of Piabucus melanostomus View in CoL :

1. Posterior laminar expansion of epiphyseal bar (1): (0> 1) present. Paralleled in Rhaphiodon vulpinus .

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

3. Posterior extent of third infraorbital (65): (0> 1) relatively reduced, angle of preopercle covered partially by fourth infraorbital. Paralleled in Hemiodus cf. thayeria , Micralestes stormsi , and Pyrrhulina australis .

4. Number of rows of premaxillary teeth (122): (1> 0) one. Paralleled in node 195 and in Aulixidens eugeniae , Carlana eigenmanni , Carnegiella strigata , Grundulus cochae , Odontostoechus lethostigmus , Paracheirodon axelrodi , and Probolodus heterostomus .

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

6. Form of posterior margin of cleithrum (233): (0> 1) with notch just anterior to pectoral-fin insertion.

7. Development of medial lamella of coracoid (238): (0> 1) expanded as a keel. Paralleled in nodes 170 and 302 and in Paragoniates alburnus , Pseudocorynopoma doriae , and Rhaphiodon vulpinus .

8. Third postcleithrum (249): (0> 1) absent. Paralleled in the Gasteropelecidae , in node 302, and in Pyrrhulina australis , Rhaphiodon vulpinus , and Xenagoniates bondi .

9. Anterior extension of pelvic-bone along main axis (262): (0> 1) projecting anterior of lateral and medial lamellae of pelvic bone. Paralleled in the Gasteropelecidae , in node 302, and in Hoplias cf. malabaricus , Rhaphiodon vulpinus , and Stethaprion erythrops .

10. Number of branched-rays on dorsal-fin (270): (1> 0) eight or fewer. Paralleled in the Stevardiinae and in Coptobrycon bilineatus , and Hoplocharax goethei .

11. Position of anteriormost epineurals (274): (0> 1) reaching to cranium. Paralleled in nodes 170, 175, and 302 and in Distichodus maculatus .

12. Numberofdorsalpterygiophores (276):(1> 0) nine.Paralleled in the Stevardiinae , in node 184, and in Hoplocharax goethei .

13. Anal-fin position (284): (0> 1) extended anteriorly ventral to dorsal fin. Paralleled in nodes 170, 208, 212, and 236.

14. Number of branched anal-fin rays (289): (0> 1) 35 or more. Paralleled in nodes 207 and 212 and in Gymnocorymbus ternetzi , Metynnis maculatus , Pseudocorynopoma doriae , Rhaphiodon vulpinus , Stethaprion erythrops , and Thoracocharax stellatus . Some trees: Paralleled in node 261 and in Markiana nigripinnis .

15. Contact between dorsal margin of adductor mandibulae and ventral margin of dilator operculi (335): (1> 0) absent. Paralleled in Creagrutus anary , Inpaichthys kerri , Prionobrama paraguayensis , Pristella maxillaris , Prodontocharax melanotus , and Pyrrhulina australis . Some trees: Paralleled in Hyphessobrycon elachys .