Prehendorastrus n. g. (Poecilostomatoida, Ergasilidae) with descriptions of two new species from the gill rakers of Hypophthalmus spp. (Teleostei, Siluriformes) from the Brazilian Amazon

Abstract

Prehendorastrus n.g. (Poecilostomatoida, Ergasilidae) is proposed for two new species (P. bidentatus and P. monodontus) collected from the gill rakers of the catfishes Hypophthalmus edentatus Spix, 1829 and H. fimbriatus Kner, 1857, from the Furo do Catal~o, near Manaus, Amazonas, Brazil. Species of the new genus are principally characterised by having antennae modified to individually grasp the gill rakers and latch, and second antennal segment with one or two prominent teeth. Prehendorastrus spp. are the first species of the Ergasilidae reported from the gill rakers of fish.

Ergasilus turucuyussp. n. (COPEPODA: ERGASILIDAE) DAS BRÂNQUIAS DE Acestrorhynchus falcatus(BLOCH, 1794) E A. falcirostris(CUVIER, 1819) (CHARACIFORMES: CHARACIDAE) DA AMAZÔNIA BRASILEIRA

“…Amplexibranchius, Brasergasilus, Miracetyma, Prehendorastrus e Rhinergasilus (BOEGER & THATCHER, 1990;CRESSEY & COLLETTE, 1970;MALTA, 1992;1993;THATCHER, 1991;VARELLA, 1992 Cefalossomo ( Fig. 1) sub-triangular, margem anterior reta, alarga-se até o terço final do cefalossomo, onde tem a maior largura, afina-se ligeiramente formando a segmentação com o primeiro somito pedígero, neste ponto apresenta uma membrana quitinosa transparente unindo a parte látero-posterior do cefalossomo com a látero-anterior do primeiro somito pedígero, margens laterais arredondadas.…”