| Hyphessobrycon comodoro|
Dagosta, Seren, Ferreira & Marinho, 2022
A new species of Hyphessobrycon is described from the rio Mutum, a tributary of the rio Juruena, rio Tapajós basin, Brazil. The new taxon can be distinguished from its congeners by the presence of a well-defined and relatively narrow dark midlateral stripe on body, extending from head to the middle caudal-fin rays, presence of a humeral blotch, distal profile of the anal fin falcate in males, 13–16 branched anal-fin rays (vs. 17–26), and 11 or 12 horizontal scale rows around caudal peduncle. The new species shows polymorphism regarding the presence of the adipose fin, and a discussion on this type of polymorphism across the family and its systematic implications is presented.
Keywords: Adipose fin, Amazon, Hyphessobrycon melanostichos, Tapajós, Taxonomy.
Hyphessobrycon comodoro, new species
Diagnose. The new species can be distinguished from all congeners, except Hyphessobrycon. cachimbensis Travassos, 1964, H. cyanotaenia Zarske & Géry, 2006, H. fernandezi Fernández-Yépez, 1972, H. melanostichos, H. nigricinctus Zarske & Géry, 2004, H. paucilepis García-Alzate, Román-Valencia & Taphorn, 2008, H. petricolus Ohara, Lima & Barros, 2017, H. piranga Camelier, Dagosta & Marinho, 2018, H. psittacus Dagosta, Marinho, Camelier & Lima, 2016, H. scholzei Ahl, 1937, H. sovichthys Schultz, 1944, H. stegemanni Géry, 1961, H. taphorni García-Alzate, Román-Valencia & Ortega, 2013, H. tuyensis García-Alzate, Román-Valencia & Taphorn, 2008, and H. vilmae Géry, 1966 by the presence of a well-defined and relatively narrow dark midlateral stripe on body, extending from head to the middle caudal-fin rays (vs. well-defined longitudinal stripe absent, or stripe wider than the orbit, or stripe starting approximately vertically through the origin of the dorsal fin or stripe blurred posteriorly). The new species is distinguished from the aforementioned species, except H. cachimbensis, H. cyanotaenia, H. melanostichos, H. nigricinctus, and H. petricolus, by the possession of a humeral blotch (vs. humeral blotch absent). It is distinguished from H. cachimbensis and H. cyanotaenia by having the distal profile of the anal fin falcate in males (vs. approximately straight or convex) and from H. cachimbensis, H. petricolus, and H. nigricinctus by having 13–16 branched anal-fin rays (vs. 17–26).It can be further distinguished from H. cyanotaenia by lacking concentration of black pigmentation on longest rays of dorsal, pelvic, and anal fins (vs. pigmentation present).It is readily distinguished from H. melanostichos, the most similar congener, by having 11 or 12 horizontal scale rows around caudal peduncle (vs. 14), fewer branched pelvic-fin rays (6 vs. 7), humeral blotch wider than deep, with pigmentation much more intense than the dark midlateral band, with well-defined edges (vs. humeral blotch deeper than wide, with pigmentation similar to the dark midlateral band, without well-defined edges). Another useful character in distinguishing H. comodoro from H. melanostichos is the presence of 13–15, mode 14, rarely 16 (only 3 of 30 specimens), branched anal-fin rays (vs. 16–18, mode 16).
Etymology. The name comodoro is in reference to the Municipality of Comodoro, Mato Grosso State, where all the specimens were collected. It is also the name of a senior naval rank used in many navies, which inspired the municipality’s name. A noun in apposition.
Fernando Cesar Paiva Dagosta, Thomaz Jefrey Seren, Anderson Ferreira and Manoela Maria Ferreira Marinho. 2022. The Emerald Green Tetra: A New restricted-range Hyphessobrycon (Characiformes: Characidae) from the upper rio Juruena, Chapada dos Parecis, Brazil. Neotrop Ichthyol. 20(1); e210119. DOI: 10.1590/1982-0224-2021-0119