Saturday, May 9, 2015

[Ichthyology • 2015] Revision of Tympanopleura Eigenmann (Siluriformes: Auchenipteridae) with Description of Two New Species; Tympanopleura cryptica & T. longipinna


Figure 1. Dorsal and ventral head profiles of species of Tympanopleura:
(a) T. atronasus, INHS 106400 (82.4 mm SL); (b) T. brevis, ANSP 194010 (63.3 mm SL); (c) T. cryptica, INHS 40163 (84.9 mm SL); (d) T. longipinna, MZUSP 114000 (73.0 mm SL, holotype); (e) T. piperata, ANSP 194022 (45.6 mm SL); (f) T. rondoni, ANSP 194015 (75.3 mm SL).
Scale bars: a-d, f = 1 cm; e = 5 mm.

The Neotropical catfish genus Tympanopleura, previously synonymized within Ageneiosus, is revalidated and included species are reviewed. Six species are recognized, two of which are described as new. Tympanopleura is distinguished from Ageneiosus by having an enlarged gas bladder not strongly encapsulated in bone; a prominent pseudotympanum consisting of an area on the side of the body devoid of epaxial musculature where the gas bladder contacts the internal coelomic wall; short, blunt head without greatly elongated jaws; and smaller adult body size. Species of Tympanopleura are distinguished from each other on the basis of unique meristic, morphometric, and pigmentation differences. Ageneiosus melanopogon and Tympanopleura nigricollis are junior synonyms of Tympanopleura atronasus. Tympanopleura alta is a junior synonym of Tympanopleura brevis. A lectotype is designated for T. brevis. Ageneiosus madeirensis is a junior synonym of Tympanopleura rondoni. Tympanopleura atronasus, T. brevis, T. longipinna, and T. rondoni are relatively widespread in the middle and upper Amazon River basin. Tympanopleura cryptica is described from relatively few specimens collected in the upper portion of the Amazon River basin in Peru and the middle portion of that basin in Brazil. Tympanopleura piperata is distributed in the upper and middle Amazon River basin, as well as in the Essequibo River drainage of Guyana.

O gênero de bagres neotropicais Tympanopleura, anteriormente sinonimizado em Ageneiosus, é revalidado e as espécies incluídas são revisadas. Seis espécies são reconhecidas, duas das quais são descritas como novas. O gênero Tympanopleura é distinto de Ageneiosus por possuir uma bexiga natatória grande e não fortemente encapsulada em osso; um pseudotímpano proeminente consistindo de uma área no lado do corpo sem musculatura epaxial onde a bexiga natatória contacta a parede interna da cavidade celômica; cabeça curta, sem mandíbulas muito prolongadas, e menor tamanho do corpo de adultos. Espécies de Tympanopleura são distintas umas das outras com base em diferenças únicas em dados merísticos, morfométricos e de pigmentação. Ageneiosus melanopogon e Tympanopleura nigricollis são sinônimos júnior de Tympanopleura atronasus. Tympanopleura alta é um sinônimo júnior de Tympanopleura brevis. Um lectótipo é designado para T. brevis. Ageneiosus madeirensis é sinônimo júnior de Tympanopleura rondoni. Tympanopleura atronasus, T. brevis, T. longipinna e T. rondoni são relativamente bem distribuídas nas porções média e alta da bacia Amazônica. Tympanopleura cryptica é descrita a partir de alguns espécimes coletados na porção alta da bacia Amazônica no Peru e porção média dessa bacia no Brasil. Tympanopleura piperata está distribuída nas regiões alta e média da bacia Amazônica, bem como na drenagem do rio Essequibo, na Guiana.

Keywords: Amazon River, Morphology, Identification key, Systematics, Taxonomy


Fig. 13. Tympanopleura cryptica, new species.
(a) holotype, MUSM 47102 (84.9 mm SL), pre-nuptial male, río Orosa, Loreto Region, Peru;
(b) paratype, INPA 35926 (65.3 mm SL), nuptial male, rio Purus, Amazonas State, Brazil.

Tympanopleura cryptica, new species 

Distribution. Tympanopleura cryptica is known from relatively few records in the middle and upper Amazon River basin, State of Amazonas in Brazil and the Loreto Region of Peru 

Etymology. The specific epithet cryptica is derived from the transliterated Greek kryptos, meaning hidden or concealed, in reference to the close morphological and pigmentation similarities of this species to congeners and its previously unrecognized taxonomic distinctiveness. Gender feminine.


Fig. 14. Tympanopleura longipinna, new species. Holotype, MZUSP 114000 (73.0 mm SL), female, rio Madeira, Rondônia State, Brazil.

Tympanopleura longipinna, new species

Distribution. Tympanopleura longipinna is broadly distributed throughout the upper and middle Amazon River basin in Brazil and Peru

Etymology. The specific epithet longipinna is derived from the Latin longus, meaning long or extended, in combination with the Latin pinna, referring to fin. The name is in reference to the long, multi-rayed anal fin of this species relative to congeners, treated as a noun in apposition. Gender feminine.


Fig. 14. Tympanopleura longipinna, new species. Holotype, MZUSP 114000 (73.0 mm SL), female, rio Madeira, Rondônia State, Brazil.
Fig. 15. Distribution of Tympanopleura longipinna (stars) and T. piperata (inverted triangles) based on material examined. Open symbols indicate type localities. Some symbols represent more than one lot or locality.


Walsh, S.J., Ribeiro, F.R.V. & Rapp-Py-Daniel, L.H. 2015. Revision of Tympanopleura Eigenmann (Siluriformes: Auchenipteridae) with Description of Two New Species. Neotropical Ichthyology, 13 (1): 1-46. DOI: 10.1590/1982-0224-20130220