Aploparaksis (Aploparaksis) xemae Schiller, 1951

Bondarenko, Svetlana & Kontrimavichus, Vytautas, 2006, Cestodes of the genus Aploparaksis Clerc, 1903 (Cyclophyllidea, Aploparaksidae) reported from gulls, with a description of new species, Journal of Natural History 40 (47 - 48), pp. 2589-2610 : 2602-2603

Aploparaksis (Aploparaksis) xemae Schiller, 1951

( Figure 8 )

Host. Xema sabini , also shorebirds of the genera Arenaria , Calidris , Gallinago , Limnodromus , Phalaropus and Tringa .

Intermediate hosts. Stylodrilus sp. , Styloscolex sokolskajae Morev (Lumbriculidae) , coelom, experimentally ( Bondarenko 1978, 1979).

Metacestode: Typical diplocyst ( Bondarenko 1978, 1979).

Localities. North America (Alaska), Siberia (the lower reaches of the Ob’, Enisey and Lena Rivers, Chukotka) .

Material studied. MHNG (Collection Neuchâtel) Diorchis serpentata 24/79, type, from Calidris sp. from West Taimyr ( Rusia), longitudinal and transverse sections; Aploparaksis xemae USNPC 47346, type, from X. sabini from Alaska, 1 mature specimen, scolex squashed; A. xemae from R. Rausch’s collection, slide 26210, X. sabini , Alaska, two mature specimens.

Addition to the Schiller’s (1951b) description (based on type). Strobila lacks gravid proglottides. Scolex squashed, but 10 aploparaksoid hooks, shape and length (25–26 mm) of which correspond well with described ones, are clearly seen. Evaginated cirrus ( Figures 8D ) short, 20 mm long, with basal swelling armed with dense, fine spines; distal region 10 mm long, unarmed. Ovary bi-winged, weakly lobed, in centre of median field; in hermaphroditic proglottides occupies almost total width of space between poral and antiporal osmoregulatory canals. Vitellarium posterior to ovary, under its anatomical centre, ventral to it. Vagina short, does not reach beyond poral osmoregulatory canals.

Remarks. Described by Schiller (1951a) on the basis of material from a single X. sabini from the Arctic coast of Alaska and was known only from this report. After re-examination of the type-specimen Bondarenko (1979) provided some additional data on the morphology of A. xemae , and established certain inaccuracies in the original description, mainly in relation to the topography of female gonads and morphology of the cirrus, which led to a misidentification: from shorebirds A. xemae was recorded as A. andrei of Belopolskaya (1969), nec A. andrei Spassky, 1965 ; A. hirsuta of Belopolskaya (1969, in part), Bondarenko (1966, in part), nec A. hirsuta ( Krabbe, 1869) ; A. orientalis of Tolkacheva in Ryzhikov et al. (1974, in part), nec A. orientalis Spassky and Bobova, 1961 ; Aploparaksis sp. of Bondarenko (1975). These corrections were introduced into the specific diagnosis of A. xemae . The elimination of inaccuracies made it possible to transfer the species from the subgenus Aploparaksis (Tanureria) where it was placed by Spassky and Yurpalova (1968) to the subgenus Aploparaksis (Aploparaksis) . It also turned out that A. xemae was first described and pictured as an unidentified species Aploparaksis sp. from a few species of shorebirds from Chukotka by Bondarenko (1975). Eggs were single or joined together into packets. Mature single eggs were contained within an additional outer coat; coalescence of the outer coats from multiple eggs results in the formation of a packet (see Figure 17 in Bondarenko 1975).

Re-examination of the type-specimens of D. serpentata von Linstow, 1905 (see above) revealed that one of them (MHNG 24/79), belongs to A. xemae (see Figure 8D ). Bondarenko and Kontrimavichus (1999) recorded A. xemae in Alaska (i.e. in ‘‘ type localities’’) from C. alpina . It is known in gulls from the first description only.

Figures

Figure 8. Aploparaksis xemae Schiller, 1951. Type-specimen from Xema sabini, Alaska: (A) hooks, (B) hermaphroditic proglottis, (C) cirrus. Specimen from a type-series Diorchis serpentata von Linstow, 1905 from Calidris sp. of Western Taimyr, Russia: (D) cirrus. Scale bars: 100 mm (B), 20 mm (A, C, D).