Redescription of Taeniacanthus aulacocephali (Copepoda: Cyclopoida: Taeniacanthidae) parasitic on Uranoscopus japonicus Houttuyn (Uranoscopidae) from Pacific coast, Japan, with adaptation of the non-destructive DNA technique.

Abstract

Taeniacanthus aulacocephali Izawa, 2021 (Copepoda: Cyclopoida: Taeniacanthidae) was redescribed from the branchial cavity and gill filaments of Uranoscopus japonicus Houttuyn (Perciformes: Uranoscopidae) collected from the Pacific coast of the Kochi and Wakayama prefectures, Japan. This is the second record of the copepod, and the finding from U. japonicus represents the new host record. The species is characterized by several distinguishing features: 1) a decrease in the width of the habitus between the second and fourth pedigerous segments; 2) the ratio of prosome/body length; 3) the presence of eight setae on the exopodal terminal segment of leg 2; 4) an un-bifurcated maxilliped claw surrounded by 14-28 transverse ridges; and 5) the presence of an inner coxal seta on legs 2 and 3. The newly collected specimens were subjected to a modified non-destructive DNA extraction method and morphological description based on the same copepod individual, while preserving a morphologically describable specimen. Sequences of 18S rDNA, 28S rDNA and the mitochondrial cytochrome c oxidase subunit 1 mitochondrial gene (cox1) were obtained.