taxonID	type	description	language	source
1E2C87A74C09DE3DFCEEE1F92F8F6AB6.taxon	materials_examined	Material examined Holotype: China, Guangdong Province, eastern Shenzhen City, Xichong beach, 22 ° 28 ′ N, 114 ° 31 ′ E, temperature of the water was 26 – 27 ° C and its salinity 19 ‰ – 20 ‰, 29 April 2017, coll. Wei-Xuan Li, PLA-Or 001, sagittal sections on three slides. Paratypes: China, Guangdong Province, eastern Shenzhen City, Xichong beach, 22 ° 28 ′ N, 114 ° 31 ′ E, 29 April 2017, water temperature: 26 – 27 ° C, salinity: 19 ‰ – 20 ‰, coll. Wei-Xuan Li, PLA-Or 002, horizontal sections on two slides; PLA-Or 003, horizontal sections on one slide; PLA-Or 004, whole mount on one slide; PLA-Or 005, whole mount on one slide; PLA-Or 006, whole mount on one slide; PLA-Or 007, whole mount on one slide; PLA-Or 008 ~ PLA-Or 012, whole mounts on five slides; PLA-Or 013, sagittal sections on three slides; PLA-Or 014, sagittal sections on three slides. All material is deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS). Etymology The specific epithet is derived from the Latin adjective geniculatus, like the bent knee, alluding to the highly curved penis papilla. Diagnosis: Oregoniplana geniculata is characterized by the following features: brown pigmentation on the entire dorsal body surface; a pair of large, prepharyngeal testes; absence of a stromatic sac attached to the ovaries; a long and slender penis papilla that is attached to the anteroventral wall of the male atrium, from where the papilla turns towards the anterior end of the body and then abruptly recurves, exhibiting a sharp U-turn in posterior direction; a horizontal female genital duct, communicating with a ventral gonopore and a secondary gonopore. Molecular diagnosis: this species comprises all individuals that are identified as a single evolutionary unit together with individuals from this study (18 S rDNA GenBank Accession numbers MK 140757 – MK 140759; 28 S rDNA GenBank Accession numbers MK 140760 – MK 140762), when using a coalescence-based molecular method for species delimitation. Description The body shape varies from elongate to ovatelanceolate, with a rounded front end and hind end (Figs 3 A – C, 4 A). In elongated state, their length ranges between 1600 and 2500 μm and their width between 290 and 510 μm (N = 5). Brownish pigmentation over a cream-colour ground is present on the whole dorsal body surface, while accumulations of pigment occur along the body margin and around the testes and ovaries (Fig. 3 A – C). A pair of black, semilunar eyes is located at a considerable distance from the anterior body margin, i. e. at about 1 / 5 of the total body length as determined from the anterior margin. The eyes are placed rather close to the body margin, the mean distance to the margin being 87 ± 9 μm (N = 5), while the distance between the eye cups ranges from 67 to 171 μm (N = 5). The eyes are located more or less dorsally to the brain and contain about 5 – 6, retinal cells (Fig. 5 A). The cylindrical pharynx lies fully in the posterior half of the body (Figs 3 C, 4 A) and measures 1 / 6 – 1 / 5 of the total body length; it measures about 365 ± 34 μm in length and 84 ± 8 μm in width (N = 5). The outer epithelium of the pharynx is underlain by a thin subepithelial layer of circular muscles, followed by a thick layer of longitudinal muscle fibres. The inner pharynx epithelium, which is densely ciliated, is underlain by a thin subepithelial layer of longitudinal muscle fibres, followed by a thick layer of circular muscles. The mouth opening is located at a distance of about 1 / 4 of the body length as measured from the posterior body margin; the mouth is situated at the posterior end of the pharyngeal cavity. The anterior branch of the intestine extends anteriorly to the eyes and gives off a pair of pre-ocellar diverticula. The posterior branches extend backwards into the tail region of the body, each of the gut trunks giving rise to 13 – 15 short, lateral diverticula; the posterior trunks do not communicate in the hind end of the body. A pair of large, ellipsoidal testes is situated immediately in front of the pharynx and directly posterior to the ovaries (Figs 3 A – D, 4 A). The testes’ follicles occupy the entire dorsoventral space and measure about 258 ± 66 μm in anteroposterior direction and about 83 ± 39 μm in width (N = 5). Narrow vasa deferentia arise from the posteroventral side of the testes and enlarge to form spermiducal vesicles at about the middle of the pharyngeal pocket, with a diameter that is about 33 ± 3 μm (N = 5). These spermiducal vesicles then extend posteriorly along either side of the pharyngeal pocket and fuse to form a common vas deferens immediately behind the pharyngeal pouch (Figs 5 E, 6). The common vas deferens opens into an irregular egg-shaped seminal vesicle that is situated at the base of the penis papilla and, subsequently, communicates with the ejaculatory duct (Fig. 3 E). The latter is lined with a nucleated epithelium and surrounded by a well-developed layer of circular muscles, the duct gradually becoming very narrow before opening at the tip of the penis papilla. The penis papilla is a long and slender cone with a unique orientation: its root is attached to the anteroventral wall of the male atrium, from where the papilla turns towards the anterior end of the body and then abruptly recurves, exhibiting a sharp U-turn in posterior direction above its own root; hereafter the distal portion of the penis papilla shows an oblique, ventrocaudal orientation, its tip more or less pointing into the ventral gonopore (Figs 4 C, 5 E, 6). A thin flap of tissue originates from the ventral atrial wall immediately posterior to the root of the penis papilla. This flap projects into the male atrium, thereby following the same course as the basal portion of the penis papilla (Figs 5 E, 6). At the level of the ventral gonopore, which is located at a distance of 1 / 19 of the body length as determined from the posterior margin, the male atrium communicates also with a horizontally oriented female genital duct that runs to the posterior body end, where it opens to the exterior via a secondary, caudal gonopore (Figs 4 D, 6). A pair of sickle-shaped, as well as pear-shaped, ovaries is situated at some distance behind the brain, i. e. at 1 / 3 to 1 / 2 of the distance between the brain and the root of the pharynx, the mean distance being about 262 ± 72 μm (N = 6); their length (in anterior – posterior direction) ranging between 77 and 135 μm, and their width between 46 and 58 μm (N = 5; Fig. 4 B). No stromatic, sac-shaped structure was found in at least ten specimens examined. The oviducts arise from the anterolateral surface of the ovaries and continue their course on either side of the pharyngeal pocket. The oviducts turn medially at the level immediately behind the ventral gonopore to open separately into the narrow, duct-like female atrium (Figs 5 B, 6). The latter receives the openings of shell glands and the separate oviducal openings, after which it communicates with the female genital duct that leads to the caudal gonopore (Figs 5 C, E; 6). Feeding and reproduction: When feeding, the thin pharynx of O. geniculata extends through the mouth opening and sucks up the soft tissues of the prey item. The worms were not able to consume either untreated pork or liver, or even to prey on live, untreated Dugesia specimens; O. geniculata was only able to consume these prey items when the tissues were artificially softened, which suggests that the pharynx is rather weak and that in nature the species depends on the availability of appropriate prey. When not starved, copulations may occur, after which one cocoon may be laid after 1 – 2 days. The flat side of the hemispherical, brown-red cocoon is attached tightly to the substrate; it is devoid of a pedicel and measures about 238 ± 4 μm in diameter (N = 5). Only one young worm hatches from each cocoon (Fig. 3 F – G). Habitat, ecology and distribution: The animals were collected at the outflow of a freshwater river or spring onto a shallow beach and thus the habitat was brackish water. From the same locality we obtained also the marine triclads Nerpa fistulata and Paucumara falcata Li & Wang, 2019, and also species from the suborder Kalyptorhynchia Graff, 1905 (see: Zhong et al., 2018), as well as many other unidentified flatworm species. Vegetation type and rainfall at this locality varies between the seasons. Alternations between the rainy season and dry season underly great variation in salinity, ranging between 15 ‰ to more than 30 ‰; the specimens of Oregoniplana geniculata are resistant to these great variations in salinity. Two plants are dominant during the various seasons, viz. Ulva lactuca and Saccharina japonica (Areschoug) Lane, Mayes, Druehl & Saunders. It is noteworthy that the marine triclad species composition is related to the dominant type of plant. In the season suitable for the growth of U. lactuca, great numbers of Paucumara falcata, an as yet unverified species of Pacifides Holmquist & Karling, 1972 and Oregoniplana geniculata are present. But when the season changes and becomes suitable for S. japonica, the only marine triclad species to be found is Nerpa fistulata.	en	Li, Wei-Xuan, Sluys, Ronald, Vila-Farré, Miquel, Chen, Jia-Jia, Yang, Ying, Li, Shuang-Fei, Wang, An-Tai (2019): A new continent in the geographic distribution of the genus Oregoniplana (Platyhelminthes: Tricladida: Maricola), its rediscovery in South Africa and its molecular phylogenetic position. Zoological Journal of the Linnean Society 187: 82-99
1E2C87A74C03DE3AFCB1E24F2F0B6A6E.taxon	materials_examined	Material examined South Africa, Cape of Good Hope, 18 ° 28 ’ 26 ” E, 34 ° 21 ’ 25 ” S, 12 October 2012, coll. Edgar Vila-Farré, ZMA V. Pl. 7284.1, sagittal sections on four slides; ZMA V. Pl. 7284.2, horizontal sections on three slides; ZMA V. Pl. 7284.3, sagittal sections on three slides; ZMA V. Pl. 7284.4, sagittal sections on seven slides. Description In elongated state, live sexually mature specimens are around 5 mm long. The body is elongated with broadly rounded hind end and moderately undulating body margins. Preserved specimens are up to 3.3 mm long, as determined from histological sections. Most of the preserved specimens are ventrally curved, with certain lateral areas protruding from the body margin, thus giving them a very singular appearance (Fig. 7 B). The two eyes are placed close to the body margin at a certain distance from the frontal margin. A small indentation at the hind end of the body is conspicuous in living and preserved specimens, corresponding to the secondary gonopore. Ventral adhesive papillae are most clearly visible at the anterior and posterior body margins. Dorsal surface of the body is dark brown, except for the tip of the head and three pairs of symmetrical patches along the body margin. Small clusters of pigment granules are densely distributed on the dorsal surface, clearly visible in animals squashed between a coverslip and a glass slide (Fig. 7 C). The ventral surface is also pigmented but paler than the dorsal one, thus making it possible to discern the large testes. The tip of the head is white, tinged light cream along the margins of the white patch. The first two, anterior-most lateral patches are white, while the third posterior one is more brownish. The first lateral patch is bigger than the others and extends from the body margin to the eyes. The second patch is placed midway between the anterior one and the posterior patch, the latter located at the level of the pharynx. These three white patches correspond to the regions protruding laterally in preserved specimens (Fig. 7 B). The eye cups (diameter 42 – 50 μm, as measured in histological sections) contain multiple retinal cells and are placed dorsally, below the body wall musculature (Fig. 8 A, B). A so-called Substanzinsel or ‘ island’ (formed by a section through a vertical tract comprised of an aggregation of ganglion cells, muscles and mesenchymatic tissue) is discernible in at least one of the cerebral ganglia of specimen ZMA V. Pl. 7284.2. A ciliated duct arises at the centre of the dorsoventral diameter of the body, very close to the dorsal surface of the brain (Fig. 8 B). From thereon, the duct runs towards the dorsal epidermis anterior to the eyes and then narrows just before opening to the exterior through the epidermis. Its diameter varies among specimens but it is usually wider near the brain. In specimens ZMA V. Pl. 7284.2 and ZMA V. Pl. 7284.4 the canal is filled with an unknown substance. The anterior branch of the intestine extends anteriorly to the eyes and gives off at least three pre-ocellar diverticula. The cylindrical pharynx lies approximately in the middle of the body and measures about 1 / 6 of the body length. The outer epithelium of the pharynx is ciliated, except close to the root of the pharynx and is underlain by a subepithelial layer of longitudinal muscles, followed by layer of circular muscles. A thick subepithelial layer of circular muscles is present underneath the inner pharynx epithelium, followed by a layer of longitudinal muscle fibres. The mouth is situated below the anterior portion of the male atrium and is connected to the pharyngeal pouch through a tubeshaped canal (Fig. 9 B). A pair of very large testis follicles is situated between the ovaries and the root of the pharynx (Fig. 7 F). In specimen ZMA V. Pl. 7284.4, the maximum diameter of the testes in anterior – posterior direction is 590 μm and their height is 300 μm, the follicles thus occupying most of the dorsoventral space. The narrow vasa deferentia arise from the posteroventral surface of the testis follicles and the ducts enlarge at the level of the pharynx to form sac-shaped vesicles that contain sperm. At the level of the base of the penis papilla, the ducts curve dorsally and, subsequently, penetrate the penis bulb to open separately into an intrabulbar cavity. From the latter arises a long ejaculatory duct that runs centrally through the penis papilla, gradually tapering towards the tip of the papilla, where the duct opens to the exterior. The ejaculatory duct is lined with a low, nucleated epithelium that widens considerably after having received a coarse cyanophilic secretion at its central section (Fig. 9 B). Abundant erythrophilic glands, located in the parenchyma just outside the penis bulb, open at the distal end of the ejaculatory duct and at two central areas of the duct (Fig. 9 B). The ejaculatory duct is surrounded by a thin layer of circular muscles, which becomes thicker at its central section (Fig. 9 B). The penis papilla is a very slender, elongated cone that is inserted at the posterodorsal wall of the male atrium. From this root, the papilla first runs sharply in the anterior direction and then exhibits an equally sharp knee-shaped bend in the caudal direction beneath its own root. This results in the fact that the tip of the penis papilla again faces the caudal end of the body. The papilla is covered with a low, nucleated epithelium that is underlain by a thin, subepithelial layer of circular muscles, followed by a layer of longitudinal muscles. However, the posterior section of the papilla is provided with a well-developed coat of muscles, consisting of two layers of obliquely oriented bundles of fibres with a cross-wise orientation (Fig. 9 C). Longitudinal muscle fibres form the small and weak penis bulb. A thin and long flap of tissue originates from the dorsal atrial wall immediately posterior to the root of the penis papilla. This flap projects into the male atrium as far as the knee-shaped bend in the penis papilla, thereby following the same course as the basal portion of the papilla. The atrium is divided into two parts. The proximal portion is narrow and corresponds to the male atrium, which houses the penis papilla and is lined with a low epithelium, underlain by a thin subepithelial layer of circular muscle fibres, followed by a layer of longitudinal fibres. The epithelium of the penis papilla frequently touches the wall of the atrium. The distal part of the atrium is tubular and is lined with a nucleated and tall epithelium, underlain by a thin, subepithelial layer of circular muscle fibres, followed by a layer of longitudinal fibres. It communicates with a gonoduct that opens to the exterior through the primary gonopore. The ventral epidermis around the primary gonopore contains numerous small, erythrophilic granules, being more abundant in the cells posterior to the gonopore. From the level of the gonoduct the tubular atrium proceeds backwards as a female genital duct, opening to the exterior by means of a secondary, caudal gonopore at the very tail end of the body (Fig. 9 A, B). At about halfway along its length, the female genital duct receives the separate openings of the oviducts at a slightly laterally enlarged section of the female duct, as well as the openings of erythrophilic shell glands that discharge anteriorly to the oviducal openings. The portion of the female genital duct running between the oviducal openings and the caudal gonopore is highly ciliated (Fig. 9 B, D). A very short duct arises from the dorsal side of the most posterior portion of the female genital duct and then opens into a small and poorly defined sac-shaped vesicle that resembles a reduced copulatory bursa. In the holotype this presumed bursa is probably connected to the intestine. The pear-shaped ovaries are situated at a short distance behind the brain, occupying a little less than half of the dorsoventral diameter of the body (Fig. 10 A). The ventral portion of each of the ovaries has a thinner wall and gives off a duct that communicates with a large sac-shaped body. This structure, called a stromatic sac by Sluys (1989), lies laterally to the ovaries and partially envelopes them, occupying most of the dorsoventral diameter of the body (Fig. 10 B). This stromatic sac is made up of nucleated cells, forming an ill-defined tissue surrounded by circular muscle fibres. The enlarged proximal section of the oviduct arises from the lateral wall of this structure, after which it immediately receives several ducts coming from vitellaria around the duct (Fig. 11 A, B). The vitellarian follicles are well developed and extend from in front of the ovaries to the level of the copulatory apparatus, usually occupying the entire dorsoventral space. The oviducts run laterally to the ventral nerve cords and at the level of the gonopore curve towards the centre of the body to open, separately, into the female genital duct. Habitat Specimens were collected from the under-surface of stones in the intertidal zone of a beach with both stones and sand.	en	Li, Wei-Xuan, Sluys, Ronald, Vila-Farré, Miquel, Chen, Jia-Jia, Yang, Ying, Li, Shuang-Fei, Wang, An-Tai (2019): A new continent in the geographic distribution of the genus Oregoniplana (Platyhelminthes: Tricladida: Maricola), its rediscovery in South Africa and its molecular phylogenetic position. Zoological Journal of the Linnean Society 187: 82-99
