Beringitaenia nanushukensis, Haukisalmi, Voitto, Hardman, Lotta M., Hoberg, Eric P. & Henttonen, Heikki, 2014

Haukisalmi, Voitto, Hardman, Lotta M., Hoberg, Eric P. & Henttonen, Heikki, 2014, Phylogenetic relationships and taxonomic revision of Paranoplocephala Lühe, 1910 sensu lato (Cestoda, Cyclophyllidea, Anoplocephalidae), Zootaxa 3873 (4), pp. 371-415 : 386-388

Beringitaenia nanushukensis n. sp.

( Fig. 11 )

Type host: Singing vole, Microtus miurus ( Cricetidae , Arvicolinae ).

Type locality: Nanushuk River, Gates of the Arctic National Park, Alaska, USA (68°16'28.2"N, 150°40'3.0"W).

Site: Small intestine.

Deposited specimens: Holotype: MSB Parasites 19033 (included in the present phylogenetic analysis). Collectors: Kyndall Hildebrandt, Juha Laakkonen, Jukka Niemimaa and Melanie Flamme. Paratype: MSB Parasites 19034, other data same as in the holotype.

Symbiotype (host voucher): University of Alaska Museum ( UAM) Mammals 79069.

Etymology. The specific epithet of the new species refers to the Nanushuk River.

Description (based on one gravid and one postmature specimen; all measurements in mm): Body short, 33 long. Number of proglottids ca. 170. Maximum width 2.5, attained in gravid proglottids. Strobila craspedote, velum long. All proglottids much wider than long, length/width ratio ca. 0.11 in mature proglottids. Last gravid proglottids longer and thinner than preceding ones. Scolex 0.470–0.485 wide and ca. 0.25 long. Neck (unsegmented region) short (0.15–0.20) and relatively wide (0.35–0.36 or 74% of scolex width). Suckers 0.195–0.220 wide, embedded within scolex, directed antero-laterally. Developing genital organs visible in first proglottids. Genital pores unilateral, opening at middle of lateral margin in mature proglottids. Genital atrium 0.05–0.10 deep. Genital ducts running between ventral and dorsal longitudinal osmoregulatory canals (could be seen only in holotype). Ventral dorsal longitudinal osmoregulatory canals 0.035–0.050 wide in mature proglottids, strongly arched, evidently connected by very narrow transverse canals (not seen). Dorsal longitudinal canals narrow (ca. 0.015 wide), strongly arched, positioned lateral to ventral longitudinal canals or partly overlapping them.

Testes ca. 35 in number, distributed as single antiporal group, median testes reaching antiporal margin of vitellarium, markedly overlapping ovary. Multiple testes extending across antiporal longitudinal canals. Cirrus sac elongate, 0.40–0.43 long and 0.11–0.12 wide in mature proglottids (when cirrus fully inverted), extending across longitudinal canals, may reach level of poral lobe of vitellarium. Everted cirrus ca. 0.20 long, tapering distally, armed densely with prominent spines (ca. 0.05 long). External muscle layers of cirrus sac thin (0.05–0.10). Internal seminal vesicle ovoid, 0.07–0.15 long in mature proglottids. External seminal vesicle with narrow distal, sometimes convoluted “neck” and small, spherical proximal expansion, covered by prominent mass of large cells in fully mature proglottids.

Ovary sparsely lobed, median, transversely elongated, 0.6–0.8 wide in mature proglottids, may reach ventral longitudinal canals on both sides. Vitellarium reniform, 0.21–0.32 wide in mature proglottids, distinctly poral, overlapping poral part of ovary. Vagina poorly seen, ca. 2/3 of cirrus sac length, running ventral to cirrus sac and opening posterior or postero-ventral to male orifice.

Seminal receptacle initially spherical, later subspherical, ovoid or slightly elongated; length in mature proglottids 0.25–0.62. Uterus first visible as fine reticulum in anterior part of mature proglottids with lateral margins extending ventrally beyond longitudinal canals. Uterus subsequently expands to fill most of proglottid, developing sparse irregular sacculations and internal trabeculae in pregravid proglottids. Cirrus sac and seminal receptacle remain in fully gravid proglottids, uterine structures practically absent. Eggs spherical or subspherical, 44–50 in larger diameter (mean 46.7). Pyriform apparatus present.

Remarks. For morphological differences between B. nanushukensis and related species, see the Remarks section for the genus Beringitaenia (above).

Figures

FIGURE 11. Beringitaenia nanushukensis n. sp. from Microtus miurus from Alaska (USA). A. Scolex and neck. B. Mature proglottid. C. Uterus in a pregravid proglottid. D. Everted cirrus. E. Tip of an everted cirrus. The position of the proximal end of the vagina is shown by an arrow.