Probolodus heterostomus

description

1. Mamilliform teeth outside mouth (120): (0> 1) present. Paralleled in nodes 218 and 277. 2. 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 Piabucus melanostomus. 3. Number of teeth in inner premaxillary row (129): (1> 0) four or fewer. Paralleled in node 198 and in Markiana nigripinnis. 4. Posterior extent of ventral process of quadrate (151): (0> 1) falling short of posterior margin of symplectic. Paralleled in the Hyphessobrycon luetkenii clade and Iguanodectinae, in nodes 284, 289, and 298, and in Astyanax mexicanus, A. cf. rutilus, Aulixidens eugeniae, Cyphocharax spilotus, Diapoma speculiferum, Hemiodus cf. thayeria, Metynnis maculatus, Micralestes stormsi, Moenkhausia sanctaefilomenae, Nematocharax venustus, Psellogrammus kennedyi, and Pseudocorynopoma doriae. Some trees: Paralleled in node 302. 5. Posterior margin of cleithrum (234): (0> 1) with concavity ventral to first postcleithrum. Reversal of synapomorphy 4 of node 204. Paralleled in nodes 196 and 289 and in Roeboexodon geryi. 6. Position of v

Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy

description

Description. Morphometrics of holotype and non-type specimens presented in Table 1. Body moderately compressed and deep, less so in individuals of less than 150 mm SL, greatest body depth within region delimited anteriorly by vertical through insertion of pelvic fin and posteriorly by vertical through origin of dorsal fin. Average body depth variable among population samples, but with broad overlap in ranges among examined samples. Dorsal profile of head distinctly convex from margin of upper lip to vertical through posterior nostril, straight to very slightly convex from latter point to tip of supraoccipital spine. Dorsal profile of body moderately convex from tip of supraoccipital spine to origin of dorsal fin, straight and posteroventrally-slanted along base of dorsal fin, straight to slightly convex from posterior terminus of base of dorsal fin to adipose fin, and slightly concave along caudal peduncle. Broad middorsal ridge present along predorsal region of body, with ridge less obvious anteriorly. Dorsal region of body between posterior terminus of dorsal fin and adipose fin transversely rounded overall, but slightly flattened middorsally in some individuals. Ventral profile

Taxonomy of Probolodus Eigenmann, 1911 (Characiformes: Characidae) with description of two new species, and comments about the phylogenetic relationships and biogeography of the genus

diagnosis

Diagnosis. Probolodus heterostomus differs from its two congeners, P. oyakawai (new species) and P. sazimai (new species) by the following attributes: 45 - 56 perforated scales on the lateral line (vs. 41 - 43 and 36 - 43 perforated scales, respectively); 18 - 21 scale series around the caudal peduncle (vs. 14 - 16 scale series around the caudal peduncle); symplectic with bone projection posteroventrally developed (vs. sympletic without bone projection) (Fig. 4 a); process extending posteriorly along the dorsal margin of the hyomandibular (vs. hyomandibular with flat margin, without process) (Fig. 4 a), and anterior portion of urohyal not bifurcated, with central orifice (vs. anterior portion of urohyal bifurcated) (Fig. 4 b).

Taxonomy of Probolodus Eigenmann, 1911 (Characiformes: Characidae) with description of two new species, and comments about the phylogenetic relationships and biogeography of the genus

discussion

Remarks. Roberts (1970) examining stomach contents of some lepidophagous characids, such as Catoprion, Exodon, Roeboides, and Roeboexodon, was the first author to observe a large number of scales in the stomachs of specimens of Probolodus heterostomus and commented on the absence, until then, of knowledge about the relationships among the lepidophagous genera aforementioned (see more details about the lepidophagous taxa in Sazima, 1977; Géry, 1980; Sazima & Uieda, 1980; Sazima & Machado, 1982; Sazima, 1983; Vari, 1986; Janovetz, 2005). Still, Roberts (1970) considered the genus P. heterostomus very similar to the tetras of the genus Astyanax. Therefore, Géry (1977) based in Eigenmann (1911, 1915) and Roberts (1970), considered P. heterostomus morphologically very similar to the tetras of the genus Astyanax, especially A. fasciatus, but both with different dentitions. According to the cited author, the tricuspidate teeth of P. heterostomus are few in number and directed outward, especially on the prominent dentary, enabling it to remove rows of scales of other fishes, possibly from the bottom up. However, Sazima (1977) suggested that A. fasciatus is the main prey of P. heterostomus,

Taxonomy of Probolodus Eigenmann, 1911 (Characiformes: Characidae) with description of two new species, and comments about the phylogenetic relationships and biogeography of the genus