 |
| Inpaichthys luizae Dagosta, 2025 |
Abstract
Inpaichthys luizae is described from tributaries of the rio dos Peixes basin, a tributary of the rio Juruena basin in central Brazil. The species is distinguished from all its congeners by the presence of well-defined, relatively broad oblique dark ventrolateral stripe on body, extending approximately from end of pectoral fin rays to base of middle caudal-fin rays, and continuing straight onto the tip of the middle caudal-fin rays. It shares seven of the eight synapomorphies attributed to the genus and exhibits all the defining characteristics of the clade I. kerri + I. parauapiranga, suggesting a close relationship with these species. Several morphological characters found in I. luizae, other species of Inpaichthys, and closely related groups are discussed. The biogeography of Inpaichthys is briefly addressed.
Keywords: Amazon; Biogeography; Rio Tapajós basin; Taxonomy
 |
| Inpaichthys luizae Life coloration of the holotype, MZUSP 130243 (male, 30.2 mm SL). Sexual dimorphism of I. luizae: A. MUBIO 691 (male, 31.5 mm SL); B. MUBIO 691 (female, 38.2 mm SL); C. Unvouchered specimen (male); D. Unvouchered specimen (female). Photos C–D by André Bulgarelli. |
Inpaichthys luizae, new species
Diagnosis. Inpaichthys luizae can be easily distinguished from all congeners by the autapomorphic presence of a well-defined, relatively broad oblique dark ventrolateral stripe on body, extending approximately from end of pectoral fin rays to base of middle caudal-fin rays, and continuing straight onto the tip of the middle caudal-fin rays (vs. well-defined longitudinal stripe absent, or dark lateral stripe never oblique). Additionally, I. luizae can also be distinguished from I. nambiquara and I. parauapiranga by the absence of humeral blotch (vs. two in I. parauapiranga and one in I. nambiquara). It is further distinguished from I. kerri by 19–21 branched anal-fin rays (vs. 22–26 branched anal-fin rays).
Fernando Cesar Paiva Dagosta. 2025. An Ode to Beauty: the Discovery of one of the most spectacular Tetras (Characiformes: Acestrorhamphidae) - A New Species of Inpaichthys from the rio Juruena, Brazil. Neotrop Ichthyol. 23(3):e250052. DOI: doi.org/10.1590/1982-0224-2025-0052
