Thursday, October 17, 2024

[Ichthyology • 2024] Rineloricaria atratoensis & R. giua • Two New Species of Rineloricaria (Siluriformes: Loricariidae) from Trans-Andean Rivers of Colombia, Unveiled through Iterative Taxonomy


Rineloricaria giua
Castellanos-Mejía, Londoño-Burbano, Ochoa, García-Alzate & DoNascimiento, 2024 

Photographs by José Luis Londoño-López

 Abstract  
Two new species of Rineloricaria are described from the trans-Andean region of Colombia. Rineloricaria atratoensis, new species, is distributed in the Atrato River and is distinguished by the absence of the mid-dorsal plate series and by having three rows of median abdominal plates, first (unbranched) ray of dorsal, pectoral, and pelvic fins extended as a short filament, and breeding males with hypertrophied odontodes on sides of head and dorsum of pectoral fin. Rineloricaria giua, new species, is found in the Magdalena and Ranchería Rivers and is distinguished by absence of mid-dorsal plate series and by having four or five rows of median abdominal plates, four plates along sides of dorsal-fin base, lateral margins of snout straight, and breeding males with hypertrophied odontodes on sides of head and dorsum of pectoral fin. Phylogenetic analyses of COI sequences of species of Rineloricaria from trans-Andean and Central American river basins revealed the different phylogenetic positions of the new species. Likewise, species delimitation analyses corroborated their status as independent lineages. An identification key for the trans-Andean and Central American species of Rineloricaria is provided.


Rineloricaria atratoensis, new species 

Diagnosis.—Rineloricaria atratoensis is distinguished from all trans-Andean and Central American congeners by having the first (unbranched) ray of dorsal, pectoral, and pelvic fins extended as a short filament (vs. coterminous with branched rays in R. altipinnis, R. giua, new species, R. jubata, R. magdalenae, R. rupestris, R. sneiderni, and R. uracantha). Rineloricaria atratoensis can also be distinguished from this group of species (except R. magdalenae) by having a paired deep depression between the nostrils and the ...

Etymology.—The species name atratoensis is in reference to its type locality, the Atrato River.



Paratypes of Rineloricaria giua, CIUA 8370, 79.5 mm SL, female, Tucuy River, Magdalena River basin, La Jagua de Ibirico, Cesar, Colombia, 9°35′13″N, 73°18′34.9″W. (A) Preserved specimen; (B) live specimen.
 Photographs by José Luis Londoño-López, copyright Colección de Ictiología de la Universidad de Antioquia; used with permission. Scale bar 1 cm.

Rineloricaria giua, new species

Diagnosis.—Rineloricaria giua is distinguished from most trans-Andean and Central American congeners (except R. jubata and R. uracantha) by having four or five rows of median abdominal plates (vs. three in R. atratoensis and R. magdalenae, more than six in R. altipinnis, R. rupestris, and R. sneiderni). Rineloricaria giua is also distinguished from this group of species (except R. magdalenae) by having lateral margins of the snout straight (vs. convex in R. altipinnis, R. atratoensis, R. jubata, R. rupestris, R. uracantha, and R. sneiderni). Rineloricaria giua differs from R. atratoensis, R. jubata and R. rupestris by having four plates along sides of dorsal-fin base (vs. five). Also, R. giua is distinguished from R. atratoensis and R. magdalenae by absence of a paired deep depression between the nostrils and the interorbital region (vs. present) and postorbital notch small and shallow (vs. large and deep). The new species is further distinguished from most of its congeners (except R. atratoensis, R. aurata, ...

Etymology.—In honor of the Grupo de Ictiología of Universidad de Antioquia (acronym GIUA). Used as a noun in apposition.


María Camila Castellanos-Mejía, Alejandro Londoño-Burbano, Luz E. Ochoa, Carlos A. García-Alzate and Carlos DoNascimiento. 2024. Two New Species of Rineloricaria (Siluriformes: Loricariidae) from Trans-Andean Rivers of Colombia, Unveiled through Iterative Taxonomy. Ichthyology & Herpetology. 112 (3), 429-443. DOI: doi.org/10.1643/i2023091  

Se describen dos especies nuevas de Rineloricaria de la región transandina de Colombia. Rineloricaria atratoensis, especie nueva, se distribuye en el río Atrato y se distingue por no tener la serie de placas dorsales medias, y por poseer tres series de placas abdominales medias, el primer radio (no ramificado) de las aletas dorsal, pectoral y pélvica extendido como un filamento corto, y machos reproductores con odontodes hipertrofiados en los lados de la cabeza y el dorso de la aleta pectoral. Rineloricaria giua, especie nueva, se encuentra en los ríos Magdalena y Ranchería y se distingue por la ausencia de la serie de placas dorsales medias, y por tener cuatro o cinco series de placas abdominales medias, cuatro placas a los lados de la base de la aleta dorsal, márgenes laterales del hocico rectos y machos reproductores con odontodes hipertrofiados en los lados de la cabeza y el dorso de la aleta pectoral. Los análisis filogenéticos de las secuencias COI de especies de Rineloricaria de las cuencas transandinas y centroamericanas, revelaron la diferente posición filogenética de las especies nuevas. Asimismo, los análisis de delimitación de especies corroboraron su condición de linajes independientes. Se proporciona una clave de identificación para las especies transandinas y centroamericanas de Rineloricaria.