Notocomplana Faubel, 1983

Oya, Yuki & Kajihara, Hiroshi, 2017, Description of a new Notocomplana species (Platyhelminthes: Acotylea), new combination and new records of Polycladida from the northeastern Sea of Japan, with a comparison of two different barcoding markers, Zootaxa 4282 (3), pp. 526-542 : 529

Notocomplana Faubel, 1983

Remarks. ConfuSion exiStS aS to the claSSification of Notoplanidae MarcuS & MarcuS, 1966 and Pleioplanidae Faubel, 1983 . The four SpecieS deScribed below could have been placed in Melloplana Faubel, 1983 (Pleioplanidae) , inStead of Notocomplana Faubel, 1983 (Notoplanidae) , becauSe theSe two genera were SuppoSed to be differentiated only by their parent familieS ( Faubel 1983), which, in fact, are likely to be SynonymouS.

The diStinction between the two familieS have been obScured from the beginning. Faubel (1983, p. 81) keyed out Pleioplanidae aS having a proStatic veSicle that had “ridged glandular lining” aS oppoSed to “tubularly chambered epithelium” in Notoplanidae . ConfuSingly, Faubel (1983, p. 115) Stated Self-contradictorily that the glandular epithelium of the proStatic veSicle waS developed to form elongated “tubular chamberS” alSo in Pleioplanidae , making the diStinction of the two familieS unSubStantiated. Moreover, Faubel (1983, p. 107) remarked that the intra-proStatic ejaculatory duct projectS “proximally” into the proStatic veSicle in Notoplanidae , although the degree of the projection varied from ‘proximally’ (i.e., cloSer to the Seminal veSicle, diStant from the male gonopore, aS in Plagiotata Plehn, 1896 ; Faubel 1983, fig. 34C) to ‘diStally’ (i.e., cloSer to the male gonopore, diStant from the Seminal veSicle, aS in Copidoplana Bock, 1913 ; Faubel 1983, fig. 34B) within the Notoplanidae sensu Faubel (1983) (later, Some genera, including Copidoplana , have been tranSferred to other familieS). Importantly, the intra-proStatic ejaculatory duct projectS into more than half the length of the proStatic veSicle—i.e., more or leSS ‘diStally’, if any—in the type genuS Notoplana ( Faubel 1983, fig. 34A); thiS holdS true in the type SpecieS Notoplana dubia ( Schmarda, 1859) (cf. Laidlaw 1903, text-fig. 51; Bock 1913, text-fig. 35; Beveridge & Cribb 2000, fig. 6). Later, BulneS et al. (2009), BulneS (2010), MaghSoudlou et al. (2015), and Rodríguez et al. (2017) developed Some important taxonomic conSiderationS in termS of the two familieS. However, the illuStration of the proStatic veSicle alleged to repreSent Notoplanidae ( BulneS 2010, fig. 9C; the intra-proStatic ejaculatory duct iS depicted to project ‘proximally’ in the proStatic veSicle) apparently doeS not illuStrate the actual character State of the organ in Notoplana dubia (See above for SubStantiating referenceS). Other characterS that SuppoSedly differentiate the two familieS (e.g., the number of the tubular chamberS in the proStatic veSicle, the manner of attachment of the intra-proStatic ejaculatory duct onto the tubular chamberS, the denSity of the tubular chamberS in the proStatic veSicle) are actually the Same in the type SpecieS of the type genera of the two familieS, Notoplana dubua and Pleioplana atomata ( Müller, 1776) (cf. Laidlaw 1903; Bock 1913; Beveridge & Cribb 2000; Tokinova 2008), implying that the two familieS are actually SynonymouS.

The four SpecieS deScribed below all conform to the definition of Notoplanidae and Notocomplana given by Faubel (1983). In termS of the anatomy of the male reproductive SyStem, they reSemble more cloSely Notocomplana humilis ( StimpSon, 1857) (type SpecieS of Notocomplana ) rather than Melloplana ferruginea ( Schmarda, 1859) (type SpecieS of Melloplana ) in—for inStance—that the intra-proStatic ejaculatory duct projectS diStally into the proStatic veSicle (See Remarks for Notocomplana japonica below). More reaSonable, reliable familial and generic affiliationS of theSe SpecieS Should be determined in future molecular SyStematic analySeS that include Such key taxa aS Notocomplana humilis , Notoplana dubia , Melloplana ferruginea , and Pleioplana atomata .