A systematic review of diapoma (teleostei: characiformes: characidae: stevardiinae: diapomini) with descriptions of two new species from southern Brazil

Abstract

Diapoma is reviewed and four species are recognized: (1) Diapoma thauma, new species, from streams of the rio Jacuí basin, state of Rio Grande do Sul; (2) D. pyrrhopteryx, new species collected from the rio Canoas and streams flowing into this basin in the states of Rio Grande do Sul and Santa Catarina, Brazil; (3) Diapoma terofali, from streams flowing into rio Uruguay in Uruguay and Rio Grande do Sul, Brazil and streams flowing into rio de la Plata, Argentina; and (4) Diapoma speculiferum, from lowland coastal streams in Rio Grande do Sul, Brazil and Uruguay. Diapoma pyrrhopteryx possess the posteroventral opercular elongation typical of D. speculiferum, type species of the genus, but which is absent in D. thauma and D. terofali. Nonetheless, all the diapomin species have the caudal pouch organ about equally developed in both sexes and the dorsal portion of the pouch opening bordered by a series of 3 to 8 elongated scales, the two derived features that characterize the group. The two previously described species, D. speculiferum and D. terofali, are redescribed. Previous hypotheses of relationships among the diapomin genera Planaltina, Diapoma and Acrobrycon are discussed on the basis of preliminary morphological information. It is proposed that the Diapomini is a monophyletic group. An identification key, information on sexual dimorphism, gonad anatomy, reproductive mode and distribution of the species of Diapoma are provided.

Molecular phylogeny of the subfamily Stevardiinae Gill, 1858 (Characiformes: Characidae): classification and the evolution of reproductive traits

“… Species analyzed for sperm morphology Diapomini Acrobrycon A. ipanquianus [ 22 ] , Acrobrycon sp. [ 69 ] Diapoma D. speculiferum [ 69 ] , D. terofali [ 69 ] M2 D. speculiferum [ 70 ] Planaltina P. britiskii [ 22 ] , P. glandipedis [ 47 ] , P. myersi [ 69 ] Glandulocaudini Glandulocauda G. melanogenys [ 69 ] , G. melanopleura [ 23 ] Lophiobrycon L. weitzmani [ 36 ] Mimagoniates M. barberi [ 69 ] , M. inequalis [ 22 ] , M. lateralis [ 69 ] , M. microlepis [ 69 ] , M. rheocharis [ 69 ] , M. sylvicola [ 69 ] M2 M. barberi [ 71 ] , M. microlepis [ 70 ] Hysteronotini Hysteronotus H. megalostomus [ 69 ] Pseudocorynopoma P. doriae [ 69 ] , P. heterandria [ 69 ] M2 P. doriae ...…”

Knodus dorsomaculatus (Characiformes: Characidae), a new species from Teles Pires River, Tapajós River basin, Brazil

“…The authors also observed secondary modifications on the dorsal fin within clade A characids, especially in Glandulocaudini and Stevardiini. Additional variation on the number of branched dorsal fin rays within clade A characids was also reported in the literature: some species has ≤8 branched rays [ii+ 7–8: Attonitus bounties (Vari & Ortega, 2000), Bryconamericus arilepis (Román‐Valencia et al , 2008 a ), B. yokiae (Román‐Valencia, 2003 c ), Cyanocharax lepiclastus (Malabarba & Weitzman, 2003), Planaltina myersi (Menezes et al , 2003), Knodus longus (Zarske & Géry, 2006) and K. moenkhausii (Ferreira, 2007); ii+ 6–8: B. tolimae (Román‐Valencia, 2004) and B. caucanus (Román‐Valencia, 2003 a ); ii+ 6–7: B. carlosi (Román‐Valencia, 2003 d ); ii+ 7: B. charalae (Román‐Valencia, 2005), B. cismontanus (Román‐Valencia, 2003 a ) and B. galvisi (Román‐Valencia, 2000)]; others species present ≥8 branched rays [ii+ 8–9: P. britskii (Menezes et al , 2003), B. gonzalezoi (Román‐Valencia, 2002), B. macrophthalmus (Román‐Valencia, 2003 b ) and B. peruanus (Román‐Valencia, 2003 a ); ii+ 8–10: B. dahlia (Román‐Valencia, 2000)]. Given the variation observed here, a more comprehensive analysis of the number of dorsal fin rays in other clade A characids genera of Malabarba & Weitzman (2003) is necessary for a better understanding of the significance of this character as a putative synapomorphy for the group.…”

Fish fauna of the Pandeiros River, a region of environmental protection for fish species in Minas Gerais state, Brazil

“…in the Pandeiros River for example, represents the first record of this genus in the São Francisco River basin. Currently, only three species of this genus have been described: Planaltina myersi from the Corumbá River (a tributary of the Paranaíba River), and Planaltina glandipedis and Planaltina britskii from tributaries of the Grande and Tietê rivers, all tributaries of the Upper Paraná River (Menezes et al 2003). Based on a bibliographic review undertaken for this study, and including Planaltina sp., the number of known freshwater fish species in the basin is 233 (Britski et al 1986;Weitzman 1999, 2000;Alves and Pompeu 2001;Lütken 2001;Reis et al 2003;Pompeu and Godinho 2003;Costa 2005Costa , 2006Costa , 2013Costa , 2014Silva et al 2006;Costa and Brasil 2006 Of the sixteen species collected upstream of the three waterfalls, Myleus altipinnis, Characidium aff.…”