New Family, New Genus, New Species of Acanthocephala (echi- Norhynchida) from the Lizard, Sphenomorphus Granulatus (sauria: Scinci- Dae), from Papua New Guinea

Sauracanthorhynchus sphenomorphicola n. gen., n. sp. from the intestines of the skink Sphenomorphus granu-latus (Scincidae) from Papua New Guinea is described and illustrated. Sauracanthorhynchus sphenomorphicola is characterized by a subterminal, spheroid proboscis supporting 25 hooks arranged in 10 alternating longitudinal rows of 2 and 3; apical hooks slightly shorter than medial and posterior hooks. The trunk is commaform with an anterior expansion; 2 contiguous ovoid testes are located in the anterior third of the trunk. Sauracanthorhynchus sphenomorphicola is sufficiently different from other species assigned to the Echinorhynchida that a new family, Sauracanthorhynchidae is erected for it.


INTRODUCTION
During necropsy of specimens of Sphenomorphus granulatus (Boulenger, 1903), no common name, a species of Acanthocephala not assignable to any known genus was found.Sphenomorphus granulatus is restricted to Milne Bay Province, Papua New Guinea (Kraus and Allison, 2004) [1].To our knowledge, there are no previous reports of helminths in S. granulatus.The purpose of this paper is to describe the acanthocephalan species found in S. granulatus.

MATERIALS AND METHODOLOGY
Three specimens of Sphenomorphus granulatus collected by hand 9-17 April 2002 by FK at Cloudy Mountain, Milne Bay Province, Papua New Guinea (10°30'S, 150°14'E), killed by an injection of Nembutol®, fixed in neutral buffered 10% formalin and deposited in the herpetological collection of the Bernice P. Bishop Museum, Honolulu, Hawaii (BPBM 15617, 15620, 15623) were examined for helminths.At necropsy, the body cavity was opened by a longitudinal lateral incision and the gastrointestinal tract was removed by cutting across the esophagus and rectum.The esophagus, stomach, small intestine, and large intestine of each skink were examined separately for endoparasites.Only acanthocephalans were found: 14 were cleared in cedarwood oil and 11 regressively stained in Delafield's hematoxylin, then mounted in balsam for examination as whole mounts; 5 were cut into serial sections of 12 μm thickness, mounted on glass slides, and stained with hematoxylin and eosin for examination.Illustrations were made using a microprojector; Photomicrographs were taken using a Nikon D70 digital camera/Leica ACT 2000 microscope.Measurements from cedarwood oil cleared specimens are given in micrometers as mean ± 1 SD with range in parentheses.
*Address correspondence to this author at the Department of Biology, Pennsylvania State University, Shenango Campus, Sharon, Pennsylvania 16146, USA; E-mail: cxb13@psu.edu

Diagnosis
As for family.Six spheroid cement glands, tandem in 3 pairs, filling space between posterior testes and Saefftigen's pouch.Uterine bell globular; uterus much longer than uterine bell; vagina short, surrounded by large sphincter; gonopore subterminal.Parasitic in Papuan lizards.

Site of Infection
Small intestine.

Etymology
The new genus is named for the order of its host; the new species is named in reference to the genus of its host.

DISCUSSION
The new species most closely resembles Hypoechinorhynchus alaeopis Yamaguti, 1939 in that both species have a subterminal, spheriod proboscis armed with 10 longitudinal rows alternating between 2 and 3 hooks each, a commaform body, and spherical contiguous testes anterior to midbody.The two species differ in that the posterior proboscis hooks are shortest in H. alaeopis, while in S. sphenomorphicola the apical hooks are shortest.Yamaguti (1939) [2] (5,6).Sauracanthorhynchus sphenomorphicola n. sp.(male).5. Entire, cedarwood oil preparation.Scale bar 125 m. 6. Sagittal section, hematoxylin and eosin.Scale bar 125 m.Abbreviations: At, anterior testis; B, bursa (withdrawn); Cg, cement glands; P, proboscis; Ps, proboscis sheath; Pt, posterior testis.nchinae), reassigned Acanthocephaloides to Echinorhynchinae, added Fresnyarhynchus Golvan, 1960 to Hypoechinorhynchinae and because Bolborhynchus was preoccupied replaced it with Bolborhynchoides Achmerow, 1959, thus reducing Hypoechinorhynchinae to 3 genera.Golvan (1969) [5] synonymized Fresnyarhynchus with Bolborhynchoides and raised Hypoechinorhynchinae to family level.Diagnostic features of the Hypoechinorhynchidae included small body size, a spineless thick-walled trunk enlarged anteriordorsally, a spherical proboscis with few large hooks, and contiguous, tandem testes (Golvan, 1969) [5].Amin (1985) [6] recognized two species in Hypoechinorhynchus, H. alaeopis (type) and H. magellanicus Szidat, 1950.Gupta and Kumar (1983) [7] described Hypoechinorhynchus golvani Gupta and Kumar, 1983 from a single male specimen; the description is considered to be inadequate and the validity of the species is questioned (Pichelin, 1999) [8].Two additional species have been described, Hypoechinorhynchus thermaceri de Buron, 1988 and Hypoechinorhynchus robustus Pichelin, 1999; all are parasites of marine fishes.Zdzitowiecki (1990) [9] in a study of Hypoechinorhynchus magellanicus found trunk spines on a male specimen and stated that trunk spines made this species consistent with the Arhythmacanthidae rather than the Hypoechinorynchidae.Pichelin (1999) [8] found trunk spines on material identified as H. alaeopis by Johnston and Edmonds (1947) [10] and illustrated trunk spines on H. robustus.Thus trunk spines are present in 3 of the 4 species; Pichelin (1999) [8] states that the absence of spines needs to be confirmed for H. thermacer.Pichelin (1999) [8] proposed because of the presence of trunk spines, a lightly armed, spherical proboscis with small basal spines and large apical hooks, six cement glands, and contiguous, tandem testes to make Hypoechinorhynchidae a junior synonym of Arhythmacanthidae.Hypoechinorhynchus was retained as a valid genus because of its unique proboscis armature, longitudinal rows which a middle spine occurs in alternate rows, an arrangement not seen in other genera of arhythmacanthids (Pichelin, 1999) [8].Given the emended description of H. alaeopis and the changed status of Hypoechinorhynchidae proposed by Pichelin (1999) [8], there is now an additional difference between the new species (absence of trunk spines) and H. alaeopis (trunk spines present) that prevents the assignment of the new species to a known family.
Among the Acanthocephala, the class Palaeacanthocephala Meyer, 1931 is characterized by the presence of lateral longitudinal lacunar canals and a double-walled proboscis receptacle (Amin, 1987) [11], The presence of these 2 characters in the new species allows its assignment to the Palaeacanthocephala.Petrochenko (1956) [3] separated families assigned to this class (his subclass Echinorhynchinea Petrochenko, 1956) into 2 orders, Echinorhynchida Southwell and MacFie, 1925 and Polymorphida Petrochenko, 1956, based upon the absence of trunk spines (Echinorhynchida) or the presence of trunk spines (Polymorphida).The absence of trunk spines allows assignment of the new species to the Echinorhynchida.Because there are no families with the unique characters of the new species, i.e., subterminal, spherical proboscis with large basal hooks, aspinose trunk with expanded anterior and contiguous testes anterior to midbody, we have erected a new family, Sauracanthorhynchidae.