Lophiobrycon Castro, Ribeiro, Benine & Melo, 2003

Menezes ¹, Naércio A. & Weitzman ², Stanley H., 2009, Systematics of the Neotropical fish subfamily Glandulocaudinae (Teleostei: Characiformes: Characidae), Neotropical Ichthyology 7 (3), pp. 295-370 : 305

Lophiobrycon Castro, Ribeiro, Benine & Melo, 2003

Lophiobrycon Castro, Ribeiro, Benine & Melo, 2003: 11 (type species: Lophiobrycon weitzmani Castro, Ribeiro, Benine & Melo, 2003: 11-19 by monotypy and original designation).

Diagnosis. Lophiobrycon can be distinguished from the other two genera of the subfamily by having the adipose fin long based in sexually mature males ( Fig. 3 ) extending from posterior termination of base of dorsal fin to base of dorsal lobe of caudal fin, a urogenital papilla ( Fig. 8 ) with a posterior opening and anus located at its base in the females, and the dorsal-fin origin closer to snout tip than to caudal-fin base. In Glandulocauda and Mimagoniates the males have a short based adipose fin ( Figs.11 and 20 ), a urogenital papilla is lacking in females and the dorsal-fin origin is closer to caudal-fin base than to snout tip. Also in Lophiobrycon only 1 to 3 hooks ( Fig. 6 ) are present on the anterior three branched anal-fin rays of adult males, contrasting with the presence of 5 to 15 hooks on the anterior three branched anal-fin rays of adult males ( Figs. 16 and 26 ) in Glandulocauda and Mimagoniates .

Remarks. Lophiobrycon shares with Glandulocauda plesiomorphic states of characters 9, 10 and 11 discussed in the phylogeny section with respect to the derived conditions of these characters in Mimagoniates . It was regarded by Castro et al. (2003: 14) as the sister group to the clade represented by Glandulocauda and Mimagoniates (see Castro et al., 2003, fig. 8). Their conclusion was based on the absence of modified scales on the upper caudal-fin lobe of Lophiobrycon ( Castro et al., 2003, fig. 4). The state described as “an apparent concentration of bead-like hypertrophied glandular tissue along the borders of the proximal portions of caudal-fin rays 11 and 12, that are slightly decurved in their distal half” would represent the most plesiomorphic state of the caudal organ in any glandulocaudine. These characters are discussed in the phylogeny section above.

Figures

Fig. 3. Lophiobrycon weitzmani, paratype, adult male, LIRP 4338, 33.1 mm SL, Brazil, Minas Gerais, rio Grande basin, upper rio Paraná, município de Delfinópolis, Estância Carmen Sílvia, córrego Bom Jesus. Modified from Castro et al. (2003).

Fig. 8. Lophiobrycon weitzmani, paratype, mature female, MZUSP83353, 18.2mmSL; urogenitalpapillaof mature female, lateral view, left side, anterior at left.

Fig. 11. Glandulocauda melanopleura, adult male. USNM 236415, 42.3 mm SL, Brazil, São Paulo State, headwater stream of rio Tietê near Paranapiacaba. Modified from Weitzman et al. (1988).

Fig. 20. Glandulocauda caerulea, adult male, USNM 326756, 43.9 mm SL, Brazil, Paraná State, brook tributary to rio Iguaçu near Lara Maria Ranch.

Fig. 6. Lophiobrycon weitzmani, paratype, adult male, LIRP 4338, 33.1 mm SL; anal-fin rays with hooks, lateral view, left side.

Fig. 16. Glandulocauda melanopleura, adult male, USNM 236415, 42.6 mm SL; anal-fin rays, lateral view, left side.

Fig. 26. Glandulocauda caerulea, adult male, USNM 326756, 39.4 mm SL; anal-fin rays, lateral view, left side.Lateral view, left side.