Two new species of freshwater turbellarians of the family Typhloplanidae (Platyhelminthes: Rhabdocoela) from China Author Huang, Wenjie Author Xie, Xiang Author Wang, Antai Author Zhang, Yu text Zoological Systematics 2023 48 2 147 158 https://www.mendeley.com/catalogue/0196cf7b-5af1-31de-bf57-0423a961b100/ journal article 10.11865/zs.2023205 2095-6827 10941802 04888FCF-480A-4198-9638-7AD4F8034E9F 3.1 Phaenocora shenda Huang & Wang , sp. nov. ( Figs 1–2 ) Etymology. The species name is derived from the abbreviated Chinese name of Shenzhen University— “Shenda”. Diagnosis. Species of Phaenocora can be in green color or colorless, depending on whether the endosymbiotic zoochlorellae is present or not. The paired ramified vitellaria extend along both sides of the body, with a reticulate appearance. The male copulatory organ is characterized by the presence of an unarmed penis papilla, while the female copulatory organ is characterized by the presence of both a genito-bursal duct and a burso-intestinal duct. Material examined. Holotype . IZCAS PLA-P001 (whole mount), a filter pond of the constructed wetland ( 22°31′45"N , 113°55′52"E ), Xiawenshan Lake , Shenzhen University , Guangdong , China , March 2021 , leg. Wenjie Huang. Paratypes . IZCAS PLA-P002–007 , same data as holotype . Description. Mature worms body length 3.05 ± 0.18 mm ( n = 6), width 1.23 ± 0.18 mm ( n = 6). Body dorsoventrally flattened and abruptly narrow at caudal end. Head somewhat rounded anteriorly and broadened posteriorly, while visible eyes absent. Individual in green color or colorless, depending on whether endosymbiotic green algae zoochlorellae present or not ( Figs 1A–B ). Brain located anterior to pharynx. Cerebral ganglion butterfly-shaped, consisting of irregular peripheral glial cells and internal nerve fibers ( Figs 1C , 2 ). Digest system made up of a pharynx, a mouth and an intestine ( Figs 1D–E , 2 ). Pharynx 613 ± 64μm ( n = 4) in length and 405 ± 51 μm ( n = 4) in width, belongs to bulbosus type . Mouth lies ventrally and can be closed by a sphincter ( Figs 1A–C , 2 ). Simultaneously hermaphroditic. Single superior genital atrium and genital pore situated ventrally, while inferior genital atrium absent ( Fig. 2 ). Female reproductive system consists of a pair of vitellaria, an ovary, an intestine bursa, a burso-intestinal duct, a genito-bursal duct, a female genital canal and a uterus ( Figs 1C–E , 2 ). Elliptic-shaped ovary located posterior to pharynx and opens dorsally to genito-bursal duct ( Fig. 2 ). Genito-bursal duct extends towards intestine bursa, connecting ventrally to female genital canal. Intestine bursa expands and opens towards intestine via burso-intestinal duct ( Figs 1D–E , 2 ). Female genital canal with a nucleated epithelium ( Figs 1E , 2 ). Paired vitellaria extend on both sides of the body in ramified form, while first half of vitellaria converge as a common vitelloduct before entering female genital canal ( Fig. 1C ). Pair testes lie dorsally or embed in vitellaria, extending on both sides of body ( Fig. 1C ). Paired vas deferentia connect to a spherical-shaped seminal vesicle. Seminal vesicle with a thickened muscular wall, and connects to unarmed penis papilla. Ejaculatory duct opens towards superior genital atrium ( Figs 1D–E , 2 ). Habitat. The worms live in an environment where Chladophora sp. is abundant. The free-living individuals move slowly by ciliary movement. They respond to light slowly. When feeding with Artemia salma under artificial culture, individuals of P. shenda Huang & Wang , sp. nov. usually swim towards the prey. Once encountering the prey, it will quickly wrap the food, stretch out the throat, and swallow the prey into the body. Distribution. China ( Guangdong ). So far only known from the type locality. Remarks. The male copulatory organ of the new species is characterized by the presence of an unarmed penis papilla. The male genital system belongs to Duplex-type IIIA. The female copulatory organ is characterized by the presence of both genito-bursal duct and burso-intestinal duct. The female genital system belongs to AGLOBULATA-type ( Houben et al. , 2014 ). A morphological comparison of the copulatory organ of the new species and three other similar species within the genus is shown in Table 3. In P. alticola Ruebush, 1939 and P. brincki Marcus, 1959 , the male and female genital systems are similar to those of P. shenda Huang & Wang , sp. nov. The body length of P. alticola ( 1.2–1.8 mm ) and P. brincki ( 2.2 mm ) is much shorter than that of P. shenda Huang & Wang , sp. nov. (3.05 ± 0.18 mm ). Moreover, in P. alticola and P. brincki , the seminal vesicle is connected to the prostate glands, while the prostate glands converge to form the prostate vesicle. In contrast, prostate glands are absent in P. shenda Huang & Wang , sp. nov. By comparing the vas deferentia, and overall body configuration and structure, the new species is most similar to P. evelinae Marcus, 1946 . In P. evelinae , each of the paired vas deferentia connects to a seminal vesicle respectively, which is the same as P. shenda Huang & Wang , sp. nov. However, the female genital system of P. evelinae is EVELINAE-type, with the presence of burso-intestinal duct, but absence of genito-bursal duct, whilst they are both present in P. shenda Huang & Wang , sp. nov. ( Houben et al. , 2014 ). Taking these differences into account, we described P.shenda Huang & Wang , sp. nov. as a new species within the genus Phaenocora .