The Dusky Palometa
Photo property of IBAMA, Pristobrycon calmoni: Brazil, Santarém , Pará
FROM FRANK MAGALLANES
Historically, this species is problem all by itself because Carl H. Eigenmann erected genus Pristobrycon using this species as the type. P. calmoni has ectopterygoid teeth and a preanal spine (so does P. aureus). This feature is absent among P. striolatus, P. careospinus and P. maculipinnis. This problem has created a situation where these last 3 species may be placed into a new generic rank as suggested by Freeman et al (2007). The assertion is based on DNA evidence collected, but is still not complete enough to withstand the test for a new genus name. Presently P. calmoni is restricted to Venezuela, however Jégu in his citations also describes it from Brazil. There are indeed similar appearing forms in Peru (see image 1 and 2 below). But it remains uncertain if these species are indeed P. calmoni or another form.
The species are generally found in areas known to be calm (lakes and pockets of water). The juveniles are mostly found in heavy vegetation, while the adults are found in smaller canals Rio Cuyuni-Essequibo. Their eating habits are variable ontogenetically and fixed. Juveniles generally consume micro-crustaceans, insects and occasionally small seeds. The adults are predators primarily during the summer, then consume fruits and seeds during the rainy season when the rainforest is flooded. It is a clear water species where it is sympatric as juveniles with P. cariba and S. rhombeus. The area also undergoes a period of a dry season from October - March. The rainy season runs from April - September. Young specimen's have bright silver bodies and may have a red, orange, or yellow anal fin with a dark border. There is a small oval humeral spot behind the opercle, fins are hyaline. The caudal fin has a terminal black band or simply a dark "V". The species is primarily found in Venezuela, however some samples have been found in other localities
Pygocentrus calmoni, described from Pará by Steindachner (1908), as a Pygocentrus was assigned as type of the genus Pristobrycon by Eigenmann (1915). The characteristics of the species place it outside the clade recognized as Pygocentrus. The type is lost. (FINK, 1993).
Pygocentrus bilineatus, described as a Pygocentrus from the Aruka River of Guyana by Eigenmann (1909), was put into synonymy of Pristobrycon calmoni by him in 1915. Types from CAS and FMNH examined (FINK, 1993).
Pygocentrus bilineatus Eigenmann, 1909, Ann Carn. Mus. VI:47
Serrasalmus coccogenys Fowler, 1911, Proc. Acad. Nat. Sci. Phil. LXIII: 428.
HISTORICAL NAMES APPLIED:
Serrasalmo (Pygocentrus) calmoni Steindachner, 1908, Anz K. Ahad. Wiss. Wien: 361.
Serrasalmus calmoni Norman 1929, Proc. Zool. Soc. London: 796.
Pygopristis gibbosus Starks, 1913, Fish. Stanf. Ich. Exp. Brazil, P. 17, lam iii.
Schulte, Wolfgang., Piranhas in the Aquarium, TFH Publications Inc. NJ pg. 87.
Fowler, H.W., Proceedings of the Academy of Natural Sciences of Philadelphia. Publishing date 7/27/1911, Fowler, H.W. . 1911 Proc. Acad. Nat. Sci. Phila.. 63:419-437.
Eigenmann, C. H. 1909 (17 Aug.) Reports on the expedition to British Guiana of the Indiana University and the Carnegie Museum, 1908. Report no. 1. Some new genera and species of fishes from British Guiana. Ann. Carnegie Mus. v. 6 (no. 1): 4-54
Henn, A. W. 1928 (Sept.) List of types of fishes in the collection of the Carnegie Museum on September 1, 1928. Ann. Carnegie Mus. v. 19 (art. 4): 51-99.
Ibarra, M. and D. J. Stewart 1987 (30 Sept.) Catalogue of type specimens of Recent fishes in Field Museum of Natural History. Fieldiana Zool. (N. S.) No. 35: 1-112.
Steindachner, F. 1908 Über sechs neue Serrasalmo- und Myletes-Arten aus Südamerika. Anz. Akad. Wiss. Wien v. 45 (no. 18): 359-367.
Fink, W. L. 1993 (18 Aug.) Revision of the piranha genus Pygocentrus (Teleostei, Characiformes). Copeia 1993 (no. 3): 665-687.
Peixes Comerciais do Médio Amazonas: Regiăo de Santarém, Pará, 1999, Fishbase
Jégu, Michel (1988), Le Genre Serrasalmus (Pisces, Serrasalmidae) dans le bas Tocantins (Brésil, Pará), S. geri, du bassin Araguaia-Tocantins.
Jégu, M. and G. M. dos Santos 2001 Mise au point ŕ propos de Serrasalmus spilopleura Kner, 1858 et réhabilitation de S. maculatus Kner, 1858 -- Valid as Pristobrycon eigenmanni (Norman 1929) (Characidae: Serrasalminae). Cybium v. 25 (no. 2): 119-143.
Freeman, B., Nico, L. G., Ostentoski, M. Jelks, H. J. & Collins, T. M. 2007. Molecular systemics of Serrasalmidae: Deciphering the identities of piranha speceis and unraveling their evoluntionary histories. Zootaxa 1484: 1-38.