Just a Vietnamese goldfish or anotherCarassius? Validity ofCarassius argenteaphthalmusNguyen & Ngo, 2001 (Teleostei: Cyprinidae)

Abstract

Freshwater fishes of the genus Carassius are widespread throughout Eurasia, but notoriously difficult for identification by morphological characters, leaving their systematics in a vague state and the validity of several species is unclear. Consequently, genetic data are used to identify the evolutionary units within this genus. Here, we present an analysis of the genus Carassius in Vietnam and south‐eastern China based on phylogenetic reconstruction using the mitochondrial cytochrome b gene and the nuclear S7 gene. We found two lineages in Vietnam with high supports in the nuclear as well as the mitochondrial dataset. One lineage corresponds to the species Carassius auratus, and one lineage represents an independent evolutionary unit. We test whether the lineage may correspond to the species that has once been described as Carassius argenteaphthalmus. The main character for identification, the color of the eye rim, did not distinguish two clades from each other. Considering the absence of genetic data, the imprecision of the original description, and the absence of all type specimens, the name of C. argenteaphthalmus is considered to be a nomen dubium.

Mitochondrial sequence diversity reveals the hybrid origin of invasive gibel carp (Carassius gibelio) populations in Hungary

“…Although gibel carps are now found in most of European waters, its taxonomy remains unsolved. The species has been grouped into the Carassius auratus -complex (CAC), which also includes, for example, C. auratus , C. gibelio , C. praecipuus , C. langsdorfii , C. cuvieri , C. carassius ( Rylkova et al, 2018 ; Takada et al, 2010 ). Some authors referred it as a subspecies of the goldfish, Carassius auratus (Linnaeus, 1758), but the others argued that the differences are not enough to list it as a subspecies and both belong to the same species C. auratus ( Berg, 1932 ; Guti, 1993 ; Pinter, 2002 ).…”