Accepted by W. Sterrer: 4 May 2016; published: 24 Jun. 2016 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2016 Magnolia Press Zootaxa 4127 (3): 567–578 http://www.mapress.com/j/zt/ Article 567 http://doi.org/10.11646/zootaxa.4127.3.9 http://zoobank.org/urn:lsid:zoobank.org:pub:F7E466CB-8EF0-468F-AEF6-542522233FB6 Pelopscreadium aegyptense n. gen., n. sp. and Pelopscreadium spongiosum (Bray & Cribb, 1998) n. comb., (Digenea: Lepocreadiidae), each from disjunct populations of the Yellow boxfish, Ostracion cubicus Linnaeus (Ostraciidae) NORMAN O. DRONEN 1 , CHARLES K. BLEND 2 , REFAAT M. A. KHALIFA 3 , HODA S. MOHAMADAIN 4 & YASSER F. M. KARAR 4 1 Laboratory of Parasitology, Department of Wildlife & Fisheries Sciences, College of Agriculture & Life Sciences, Texas A&M Uni- versity, College Station, Texas 77843-2258, USA. E-mail: n-dronen@tamu.edu 2 58 Rock Creek Drive, Corpus Christi, Texas 78412-4214, USA. E-mail: ilovethesea@att.net 3 Department of Medical Parasitology, Faculty of Medicine, Assiut University, 71515 Assiut, Egypt. E-mail: rkhalifa_eg@yahoo.com 4 Department of Zoology, Faculty of Sciences, South Valley University, 83523 Qena, Egypt. E-mail: dr_hodasm60@yahoo.com; yasser.karar@sci.svu.edu.eg Abstract Bianium spongiosum Bray & Cribb, 1998 (Lepocreadiidae), described from the yellow boxfish, Ostracion cubicus Lin- naeus (Ostraciidae), off Lizard Island, Queensland, Australia, possesses a combination of the following three morpholog- ical features which distinguishes it from all the other species currently assigned to the genus: (1) large internal patches of large cells forming sponge-like pads we have termed “pelops”(“pelop” sing.) laterally in the forebody extending from near the anterior extremity to about the level of the intestinal bifurcation rather than possessing a scoop; (2) ceca that reach to near the posterior extremity where they end blindly without ani; and (3) a vitellarium which is present laterally but not dorsal to the ceca. Based on this we propose the erection of Pelopscreadium n. gen. (Lepocreadiidae) with the assignment of B. spongiosum to this new genus as the type-species, Pelopscreadium spongiosum (Bray & Cribb, 1998) n. comb. Pelopscreadium aegyptense n. sp., also from the yellow boxfish but from the Red Sea off Sharm El-Naga, Egypt, is de- scribed as the second member of the new genus because it shares these three characteristics with P . spongiosum. Key words: Australia, Egypt, Lepocreadiidae, Lizard Island, Ostraciidae, Ostracion cubicus, Pelops, Pelopscreadium n. gen., Pelopscreadium aegyptense n. sp., Pelopscreadium spongiosum n. gen, n. comb., Red Sea, Yellow boxfish Introduction Stunkard (1930) erected Bianium Stunkard, 1930 based on a single specimen identified by Linton (1898) as “Distomum sp.” that had been collected from the intestine of the smooth puffer, Lagocephalus laevigatus (Linnaeus) (Tetraodontidae), in Narragansett Bay off Woods Hole, Massachusetts, USA. Stunkard (1930) noted that the individual worm possessed “two ceca that each opened posteriorly by way of an anus” (hence Bianium), and, based on Linton’s material, he described Bianium concavum Stunkard, 1930. Stunkard (1931) also examined the type-specimen of Psilostomum plicitum Linton, 1928, originally described by Linton (1928) from the intestine of the herring gull, Larus argentatus Pontoppidan (most likely the American or Smithsonian herring gull, Larus smithsonianus Coues) (Laridae), off Woods Hole, Massachusetts. He concluded that B. concavum was a junior synonym of Bianium plicitum (Linton, 1928) Stunkard, 1931; however, as P . plicitum was not in Bianium when Stunkard (1930) established the genus with the description of B. concavum, the latter would have to be considered the type-species of Bianium. To address the difficulty of the adult stage of B. plicitum utilizing both a fish and bird host, Stunkard (1931) stated, “From the observations of Linton, it appears that fish parasites may persist for a time in the intestine of piscivorous birds” (i.e. the presence of B. plicitum in a gull was an accidental infection). Sogandares-Bernal & Hutton (1958) examined B. plicitum and specimens of Diploproctodaeum La Rue, 1926 (D. haustrum [MacCallum, 1919] La Rue, 1926; syn. Hemistomum haustrum MacCallum, 1919) and concluded