Notocomplana palta ( Marcus 1954 ) Faubel 1983

Brusa, Francisco & Damborenea, Cristina, 2011, Polycladida Acotylea from Patagonia. Redescription of Crassiplana albatrossi (Pseudostylochidae), lectotype designation and first record of Notocomplana palta (Notoplanidae), Zootaxa 2903, pp. 29-38 : 34-36

Notocomplana palta ( Marcus 1954) Faubel 1983

Synonym: Notoplana palta Marcus 1954

Material examined. Specimens of Notocomplana palta were provided by the Swedish Museum of Natural History, Stockholm, Sweden ( SMNH). We designate as lectotype the specimen SMNH 110097- 110101 from the series of animals studied by Marcus (1954). New specimens were collected in 2006–2009 at different localities along the Patagonian coast; these are housed in the Invertebrate Zoology collection at the MLP (Table 1, Figure 1 ).

Description. Live specimens are light to dark orange-colored ( Figure 5 B). Central zone where pharynx is placed is darker. Body ovate and with ruffled edges. Studied specimens measure 10–20 mm long and 5–9 mm wide.

Tentacles absent. Eyes placed in medial region, associated to brain zone. Brain eyes rounded, small, numbering 35 to 40 on each side. Tentacular eyes posterior to brain eyes, larger, and approximately ten on each side. Very small eyes in parenchyma ventrally and anteriorly to brain ( Figure 5 A).

Ventral and dorsal epidermis ciliated. Ventral cilia longer. Rhabdites on both surfaces, more abundant on ventral epidermis. Basal membrane thick, the ventral one being thinner than the height of the epithelium; dorsal basal membrane thickness equal to the epithelium height, folded in some of the thin sections. Body-wall musculature on dorsal surface consisting of an external thin circular layer, a diagonal middle layer (the thickest) and a longitudinal internal layer; a second internal circular layer is crossed by dorso-ventral muscles. On the ventral surface of the body, musculature is longitudinal, followed internally by a thin circular layer; the latter is packed inwards.

Pharynx ruffled (approximately nine folds), placed in front of mid-length of body. Epithelium lining the pharynx cavity is ciliated. Mouth slightly behind mid-length of pharynx ( Figure 5 C).

Testicles ventral and ovaries dorsal, distributed throughout body length, including the region in front of the brain.

Deferent ducts (one pair) thickenning and twisting before joining seminal vesicle. Seminal vesicle strongly muscular, rounded to oval. Ejaculatory duct long, thin and muscular. A short portion of ejaculatory duct projects into prostatic vesicle, which shows a tall and folded epithelium. Lumen of prostatic vesicle continuous with the lumen of penis papilla ( Figure 4 ). Penis papilla conical, located in a male atrium and opening into a male pore (Figure 5E, H–I).

Female gonopore posterior to male pore ( Figure 4 ). Muscular vagina inlaid with ciliate epithelium; shape sigmoidal, and lying perpendicular to surface in its first part, then running anteriorly, and later turning posteriorly. In female specimens, the portion reaching anteriorly carries abundant cement glands that open into that part of the vagina ( Figures 4 , 5 D, F).

Uteri loaded with ovocites and continuing into two uterine ducts that join to form a single ciliate duct. The latter joins the proximal part of vagina at its ventral surface.

Lang´s vesicle channel present after junction of uterus and vagina. This channel shows constrictions that give it a beaded appearance; it opens into Lang’s vesicle. At the junction of vesicle and duct there is a sphincter. Vesicle rounded to ovate, lined with a tall vacuolar epithelium, with scarce muscular fibres. Sperms were observed within it ( Figures 4 , 5 D, G).

Remarks. This species was originally described by Marcus (1954) from the fjord region in southern Chile. The Patagonian specimens clearly agree with the original description of the species ( Marcus, 1954) and with the material he had available for study (SMNH110097- 110101).

Bulnes (2009) recently mentioned Notocomplana palta in an area close to the type locality but the description given by this author does not agree with the original desciption ( Marcus, 1954). Bulnes (2009) described small tentacles, a thin and short penis papilla, and a four-chambered seminal vesicle. These structures were not mentioned in the original description of this species ( Marcus, 1954) nor are they present in the material studied by him and housed in the SMNH. Therefore, they can not be considered part of this taxon.

The material housed in the SMNH was not designated originally as type material. To avoid future misidentifications of Notocomplana palta , the specimen described and illustrated by Marcus in the original work ( Marcus 1954; 65; figs. 99, 101) and from the type locality (as recorded on the original label St. M 21) is designated as the lectotype under Article 74 of the fourth edition of ICZN (1999). The presence of this species along the Patagonian coast and southern Chile suggests a Magellanic distribution similar to that of other species of invertebrates (e.g. Boschi 2000, Balech & Ehrlich 2008).

Figures

FIGURE 1. Localities where the polyclads were found. Crassiplana albatrossi (squares) and Notocomplana palta (asterisks). A, general view with the type localities and the new localities. B, details of the localities in Peninsula Valdes and neigbour zones. The numbers of the localities correspond to table 1.

FIGURE 4. Notocomplana palta. Sagittal reconstruction of adult specimen.

FIGURE 5. Notocomplana palta. A, dorsal view of adult specimen. B, live specimens on the stone. Sagittal secctions. C, general view of adult specimen. D, detail of the female organs. E, detail of the male organs. F, detail of the ovary and the first portion of the oviduct. G, Lang`s vesicle, detail of the sphincter and spermatozoids in the vesicle. H, penis papilla and the prostatic vesicle with the linning epithelium ridge. I, prostatic vesicle with the chambers.