2026/07/10 by He-Cai Zhang, Junhua He, Y H Zhang +4 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Environmental Science · #Parasite Biology and Host Interactions #Planarian Biology and Electrostimulation #Tardigrade Biology and Ecology
paper · pdf · doi:10.3897/zse.102.185506
openalex publication_date 2026/07/10 · openalex created_date 2026/07/11 · openalex updated_date 2026/07/15
Three new species of the genus Dugesia from Henan Province in central China, Dugesia tongbaiensis Chen & Zhang, sp. nov ., Dugesia fangchengensis Chen & Zhang, sp. nov ., and Dugesia lushanensis Chen & Zhang, sp. nov . are described based on an integrative approach involving morphological, histological, karyological, and molecular analyses. Dugesia tongbaiensis is characterized by the following features: a long duct intercalated between the slender saclike seminal vesicle and the diaphragms; two well-developed adjacent diaphragms, with the posterior one larger than the anterior one; an ejaculatory duct running a central course through the penis papilla with a terminal opening; a mixoploid karyotype with diploid chromosome portrait of 2n = 2x = 16 and triploid chromosome complement of 2n = 3x = 24, and all chromosomes being metacentric. Dugesia fangchengensis is characterized by the following features: two asymmetric bumps on the middle of the penis papilla, giving it an approximately gyroscopic shape; a pointed diaphragm located at the mid-length of the penis papilla; a short ejaculatory duct displaced ventrally with terminal opening; an asymmetric penis papilla whose dorsal lip is thicker than its ventral one; a mixoploid karyotype comprising diploid (2n = 2x = 16) and triploid (2n = 3x = 24) metacentric chromosome complements. Dugesia lushanensis is characterized by the following features: a strongly asymmetric penial valve existing at the base of the penis papilla, with the dorsal portion much larger than the ventral one; a well-developed diaphragm separating the ellipsoidal seminal vesicle from the inverted V-shaped ejaculatory duct; a ventrally displaced ejaculatory duct with a subterminal opening; a highly asymmetric penis papilla, with the dorsal lip thicker and longer than the ventral one; a dorsal bump positioned at halfway the length of the penis papilla. This species exhibits a purely diploid karyotype (2n = 2x = 16) with entirely metacentric chromosomes. The three new species are nested within the Eastern Palearctic/Oriental/Australasian clade but form distinct subgroups in the molecular phylogenetic tree. Their valid species status is supported by molecular genetic distance analyses.