C. Román–Valencia, R. I. Ruiz–C., D. C. Taphorn B., P. Jiménez–Prado & C. A. García–Alzate
Abstract
A new species of Bryconamericus (Characiformes, Stevardiinae, Characidae) from the Pacifc coast of northwes- tern Ecuador, South America.— A new species of Bryconamericus (Characiformes, Characidae, Stevardiinae) is described from the Pacifc coast of northwestern Ecuador, South America. The new species is distinguished from all congeners by the presence in males of bony hooks on the caudal fn rays (vs. absence). The different layers of pigment that constitute the humeral spots have differing degrees of development and structure that are independent of each other. Brown melanophores are distributed in a thin, vertical, superfcial layer of the epithelium (layer 1) and in another deeper (layer 2) that overlaps the frst and is centered over the lateral–line. B. ecuadorensis has a horizontally oval or elliptical shape layer 2 pigment in the anterior humeral spot (vs. a rectangular or circular layer 2). The new species further differs in having an anterior extension of the caudal peduncle spot (vs. no anterior extension of the caudal peduncle spot) and by having a dark lateral stripe overlaid by the peduncular spot and by the regularly distributed pigmentation on scales on the sides of the body (vs. peduncular spot and other body pigments not superimposed over a dark lateral stripe). Hooks present on all fns of males (vs. hooks present only on anal and pelvic fns of males) distinguishes the new species from B. dahli, the only sympatric congener. Seven other diagnostic characters separating the new taxon from B. dahli are reported. We also include physical, chemical and biological habitat parameters and analyse the impacts from mining on this new species and other organisms present at the type locality.