Cynolebias parnaibensis, a new seasonal killifish from the Caatinga, Parnaíba River basin, northeastern Brazil, with notes on sound producing courtship behavior (Cyprinodontiformes: Rivulidae)

Abstract

Cynolebias parnaibensis from the Canindé River drainage, Parnaíba River basin, northeastern Brazil, is described. It is considered to be a member of a clade endemic to the Caatinga. The clade is diagnosed, e.g., by a series of structural modifications of the pharyngeal jaw apparatus, which is related to the sound production exhibited by males during courtship behavior. The courtship sound of C. parnaibensis consists of a single pulse named as thump (duration 0.031-0.133s; interthump intervals 0.020-8.319s; dominant frequency 70.3-93.8 Hz). The new species is distinguished from all other congeners by a combination of 27-31 neuromasts around eye, 29-33 supraorbital neuromasts, 16-18 dorsal-fin rays and 19 anal-fin rays in males, 28-31 caudal-fin rays, 33-36 scales in the longitudinal series, 3+10 gill-rakers in the first branchial arch, absence of second pharyngobranchial teeth, absence of contact organs on the flank scales, 34-35 vertebrae, absence of teeth on vomer, and presence of transverse series of scales on the anal-fin base.Cynolebias parnaibensis, da drenagem do rio Canindé, bacia do rio Parnaíba, nordeste do Brasil, é descrita. Ela é considerada um membro de um clado endêmico da Caatinga. O clado é diagnosticado, e.g., por uma série de modificações estruturais do aparato mandibular faringiano, que está relacionado à produção de som exibida por machos durante o comportamento de corte. O som de corte de C. parnaibensis consiste de um único pulso denominado como thump (duração 0,031-0,133s; intervalos entre thumps 0,020-8,319s; frequência dominante 70,3-93,8 Hz). A nova espécie se distingue de todos os outros congêneres por uma combinação de 27-31 neuromastos em torno do olho, 29-33 neuromastos supraorbitais, 16-18 raios na nadadeira dorsal e 19 raios na nadadeira anal em machos, 28-31 raios na nadadeira caudal, 33-36 escamas na série longitudinal, 3+10 rastros branquiais no primeiro arco branquial, ausência de dentes no segundo faringobranquial, ausência de órgãos de contato nas escamas do flanco, 34-35 vértebras, ausência de dentes no vomer e presença de séries transversais de escamas na base da nadadeira anal.

Description of two endangered new seasonal killifish species of the genus Cynolebias from the São Francisco River basin, Brazilian Caatinga (Cyprinodontiformes, Aplocheilidae)

“…attenuatus, C. leptocephalus, C. gorutuba, C. oticus, C. parietalis, C. perforatus). Species of the H. magnificus group are commonly found in shaded parts of temporary pools that are protected by dense bush vegetation (e.g., Costa 2010). In recent pools, just after first rains when all seasonal killifish species are represented by juveniles, species of the H. magnificus group are abundant.…”

“…Cynolebias has been divided in two subgenera, Bathylebias Costa, 2008, with a single species endemic to the seasonal dry forest of the Paranã valley in central Brazil, and Cynolebias, comprising 16 species endemic to the Caatinga of northeastern Brazil (Costa 2001(Costa , 2008(Costa , 2014. Members of the latter subgenus are unique among Neotropical killifishes in having males that produce sounds during courtship behaviour (Belote and Costa 2003;Costa et al 2010), using a morphologically complex pharyngeal apparatus (Costa 2009a). In contrast to most aplocheilid killifishes that are small, usually not surpassing 80 mm of standard length (SL), some species of Cynolebias often reach between 100 and 120 mm SL, and supposedly prey on small sympatric seasonal killifishes (Costa 2001).…”

“…All species of Cynolebias, except C. porosus Steindachner, 1876, were described after 1990 as a result of frequent recent efforts to sample the temporary pools of the Brazilian seasonal dry forests (e.g., Brasil 1991, 1993;Costa 2001Costa , 2014Costa et al 2010). The subgenus Cynolebias has been divided in three species groups (e.g., Costa 2014), the C. gilbertoi, C. porosus and C. perforatus groups.…”

Ichthyofauna of coastal lakes and the Igaraçu River in Ilha Grande, Delta do Parnaíba, Parnaíba, Piauí State, northeastern Brazil

“…The knowledge about the number of fish species occurring in the Parnaíba River was based on literature compilation, which included original descriptions, check lists and catalogues of Brazilian fish species until recently (Eigenmann 1910;Fowler 1954;Reis et al 2003;Rosa et al 2003;Buckup et al 2007;Costa et al 2010). This information source enabled Albert et al (2011) to characterize the fish fauna o Parnaiba River as potentially diverse with an estimative of about 95 species.…”

Female Annual Killifish Austrolebias reicherti (Cyprinodontiformes, Rivulidae) Attend to Male Chemical Cues

“…In fact, acoustic communication has been reported for annual fish of the genus Cynolebias (Belote & Costa ; Costa et al. ), and chemical communication may also be favoured for mate finding and selection.…”