Vertebrate Zoology 58(2): 173-196, doi:
Revision der neotypischen Gattung Metynnis COPE, 1878. II. Beschreibung zweier neuer Arten und zum Status von Metynnis goeldii EIGENMANN, 1903 (Teleostei: Characiformes: Serrasalmidae)
expand article infoAxel Zarske‡, JACQUES Géry
‡ Senckenberg Naturhistorische Sammlungen Dresden, Museum für Tierkunde,, Dresden,, Germany

Corresponding author: Axel Zarske ( axel.zarske@senckenberg.de )

© Axel Zarske, JACQUES Géry.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Zarske A, Géry J (2008) Revision der neotypischen Gattung Metynnis COPE, 1878. II. Beschreibung zweier neuer Arten und zum Status von Metynnis goeldii EIGENMANN, 1903 (Teleostei: Characiformes: Serrasalmidae). Vertebrate Zoology 58(2): 173-196
Open Access
Abstract
Metynnis longipinnis sp. n. – a new species of Silverdollar from the río Casiquiare drainage in Venezuela is described. The new species is closely related to Metynnis hypsauchen (MÜLLER & TROSCHEL, 1844) according to its features (1) high number of gill-rakers, (2) long adipose fin, (3) deep body, (4) short head and (5) long occipitale and is clearly defined because of (1) the high number of serrae (36–37 vs. 27–32 of M. hypsauchen), (2) the small scales (91–93 vs. about 75–83), (3) uniformly silver colouration and (4) the extremely elongated dorsal fin and anal fin. From Metynnis altidorsalis AHL, 1924 the new species is clearly differentiated by its (1) number of gill-rakers (30–33 vs. 20–25 for M. altidorsalis), (2) the number of branched anal rays (37–40 vs. 32–37 for M. altidorsalis), (3) the number of serrae (36–37 vs. 29–35 for M. altidorsalis) and (4) the length of the occipitale (18.94–20.78 % SL vs. 11.7–15.6 for M. altidorsalis). Further on M. longipinnis sp. n. has a longer adipose fin (20.00–20.78 % SL vs. 11.8–16.2 for M. altidorsalis) and an elongation of the rays of dorsal and anal fin (vs. not elongated for M. altidorsalis). M. luna COPE, 1878, M. orinocensis (STEINDACHNER, 1908) and M. guaporensis EIGENMANN, 1915 are differentiated by its higher number of gill-rakers and lager head length. M. lippincottianus (COPE, 1870) has a completely different colouration. Metynnis polystictus sp. n. – a new species of Silverdollar from the río Xingu in Brazil is described. The new species is closely related to Metynnis anisurus AHL, 1924, which is considered as valid. M. polystictus sp. n. is clearly differentiated from M. anisurus by its (1) colouration (body without spots in M. anisurus vs. two different kinds of spots in M. polystictus sp. n.) and (2) the enlarged lower lobe of caudal fin (developed in M. anisurus vs. absent in M. polystictus sp. n.). The Synonymy of Metynnis goeldii EIGENMANN, 1903 with Metynnis lippincottinianus (COPE, 1870) could be confi rmed, because of the rediscovery of a syntype of Metynnis goeldii EIGENMANN, 1903 in the collection of the California Academy of Sciences (San Francisco).
Keywords
Taxonomie, Teleostei, Characiformes, Serrasalmidae, Metynnis, new species, río Casiquiare, Venezuela, rio Xingu, Brasilien, Lectotypus-Festlegung, Synonymie.