Peruanocotyle, Chero & Cruces & Sáez & Luque, 2018

Chero, Jhon D., Cruces, Celso L., Sáez, Gloria & Luque, José L., 2018, A new genus and species of the Dasybatotreminae Bychowsky, 1957 (Monogenea: Monocotylidae), parasitic on Hypanus dipterurus (Jordan & Gilbert) (Myliobatiformes: Dasyatidae) in the Southeastern Pacific Ocean off Peru, Zootaxa 4527 (3), pp. 347-356 : 349

Peruanocotyle n. gen.

Type species: Peruanocotyle chisholmae n. gen., n. sp.

Etymology: The genus name refers to the country where the specimens were found.

Diagnosis: Monocotylidae . Dasybatotreminae . Body comprising body proper (cephalic region and trunk) and haptor. Anterior attachment organ well-developed, broadly ovoid, with oblique grooves, an anteromedial notch and numerous anterior gland duct openings. Three prominent anterior glands (one medial and two laterals) containing granular secretion present. Numerous peripheral glands starting from anterior glands, encircling oral opening. Eyespots absent. Mouth surrounded by numerous small dome-like papillae. Intestinal ceca with large lateral and medial diverticula, diverticula extending from anterior to posterior end of body proper, not confluent posteriorly. Trunk panduriform. Haptor having one central loculus and eight peripheral loculi. Marginal membrane present. Marginal haptoral papillae, papillary sclerites, septal sclerites, sinuous sclerotised septal ridge, dorsal haptoral unsclerotised protuberances and dorsal haptoral accessory sclerites absent. Anchors (= hamuli) present, much shorter than width of marginal membrane, with deep root elongate and superficial root not reduced. Accessory sclerotized piece on the anchor present. Seven pairs of similar hooks distributed in marginal membrane, each with short sweeping point and slightly narrow shack. Testes four, arranged in two groups of two testes. Ejaculatory duct with slightly sclerotized walls, having proximal (with criss-crossed creases) and distal portion (highly convoluted). Ejaculatory bulb well-developed, highly muscular, with one bipartite internal seminal vesicle (=spherical internal chamber); distal portion of ejaculatory bulb with numerous male accessory glands. Male copulatory organ (MCO) sclerotized, composed of four connate tubes (one tube more or less attached parallel to another tubes). Accessory piece present. Accessory filament of MCO absent. Sheath absent. Ovary looping right intestinal cecum, with proximal and distal portions; proximal ovary with six clavate lobes; distal ovary tube-like, strongly coiled. Vagina single, vaginal wall sclerotized; vaginal pore unarmed. Common genital pore unarmed. Gill parasites of dasyatids (stingrays).

Remarks: As stated by Chisholm et al. (2001), the Monocotylidae includes 7 recognized subfamilies with species that parasitize exclusively marine and freshwater chondrichthyans, namely Calicotylinae Monticelli, 1903; Dasybatotreminae ; Decacotylinae Chisholm, Wheelerv & Beverley-Burton, 1995; Euzetiinae Chisholm & Whittington, 2001; Heterocotylinae Chisholm, Wheeler & Beverley-Burton, 1995; Merizocotylinae Johnston & Tiegs, 1922 and Monocotylinae Taschenberg, 1879. The new genus is placed in the Dasybatotreminae by having an anterior attachment organ with numerous anterior gland duct openings and an elongate deep root on the anchors (Chisholm et al. 2001). The subfamily currently includes four genera parasitizing marine chondrichthyans, Anoplocotyloides Young, 1967 ; Dasybatotrema Price, 1938 ; Mehracotyle Neifar, Euzet & Ben Hassine, 2002 and Timofeevia Chisholm, Wheeler & Beverley-Burton, 1995 (Chisholm et al. 2001, Neifar et al. 2002). Peruanocotyle n. gen. can be readily distinguished from the other genera of the Dasybatotreminae by the morphology of the cephalic region, which is unique in the subfamily in possessing a broadly ovoid anterior attachment organ, having numerous grooves and an antero-medial notch and by having anchors much shorter than the width of marginal membrane. In addition, the new taxa can be differentiated from all other species of the Dasybatotreminae by having three prominent anterior glands, which originating from numerous peripheral glands that encircling oral opening and by the morphology of the male copulatory organ, which is composed of four connate tubes. Additionally, the new taxa also differs from all previously described in the subfamily by the following combination of characters: haptor with one central and eight peripheral loculi; ovary having proximal (with six clavate lobules) and distal (strongly coiled) portions; ejaculatory duct with slightly sclerotized walls, having proximal (with criss-crossed creases) and distal portion (highly convoluted); ejaculatory bulb with one bipartite internal seminal vesicle; anchor with an accessory sclerotized piece; intestinal caeca with large lateral and medial diverticula; oral opening surrounded by numerous small papillae; and four oval testes.