A new species of the Hoplias malabaricus (Characiformes: Erythrinidae) species complex from the Plata River basin

ROSSO, JUAN JOSE; MABRAGAÑA, EZEQUIEL; GONZÁLEZ CASTRO, MARIANO; DELPIANI, SERGIO MATIAS; AVIGLIANO, ESTEBAN; SCHENONE, NAHUEL FRANCISCO; DÍAZ DE ASTARLOA, JUAN MARTÍN

CYBIUM

SOC FRANCAISE D ICHTYOLOGIE

Lugar: Paris; Año: 2016 vol. 40 p. 199 - 208

0399-0974

Hoplias malabaricus is one of the 12 valid species in the genus Hoplias, the most diverse genus amongthe Erythrinidae. Cytogenetic studies during the last decades had shown that thisspecies represents a well-populated species complex. The new species of the Hoplias malabaricus group is described fromthe Uruguay, Paraná and Paraguay Rivers, in Argentina and Brazil. The Y-shapedconfiguration of the medial margin of dentaries easily separates Hoplias misionera n. sp. from all the remainder species of Hoplias (parallel-shaped in Hoplias lacerdae group and Hoplias aimara and V-shaped in Hoplias malabaricus group). Hoplias misionera n. sp. can be further distinguished from species in the Hoplias malabaricus group by additionalcharacters other than medial margin of dentaries. The total number of dorsal(14-16 vs. 14) and pectoral (12-14 vs. 11) fin rays and the number of scales inlateral line (40-43 vs. 38-39) further distinguishes Hoplias misionera n. sp. from Hopliasmalabaricus. Hoplias misionera n.sp. differs from H. microlepis inunbranched (2-4 vs. 2) dorsal-fin rays, the number of scales along lateral line(40-43 vs. 43-47) and a lower number of scales around the caudal peduncle (20vs. 22-24, usually 24). Hoplias misioneran. sp. differs from H. teres bynumber of scales in lateral line (40-43 vs. 38), number of total (14-16 vs. 13)and unbranched (2-4 vs. 3) dorsal-fin rays and pectoral (12-14 vs. 13-15) finrays, total vertebrae count (39-40 vs. 42), larger dorsal-fin base (16.7-20.9vs. 16.2-17.6 % SL) and body depth (20.6-25.4 vs. 17-20.6 % SL). Finally, Hoplias misionera n. sp. can be distinguished from the recently described Hoplias mbigua by a distinctly shortersnout length (20.4-24.7 vs. 25.2-28.6 % HL) and lower pre-nasal distance (12.5-16.2vs. 15.2-18.4 % HL). Hoplias misionerafurther differs from Hoplias mbiguaby dorsal profile of head markedly straight vs. dorsal profile of head markedlyconcave; lower jaw with either brown bands, dots or blotches vs. always fivedistinctive transversally brown bands; infraorbital 5 lacking pores inlaterosensory canal vs. infraorbital 5 with one pore, last vertical series ofscales on caudal peduncle forming marked curve vs. forming a relativelystraight line. Finally, color pattern also contributes to the discriminationbetween H. misionera and H. mbigua.