Cairaeanthus ruhnkei Kornyushin & Polyakova, 2012 parasite in collection

Type host

Dasyatis pastinaca (Linnaeus, 1758)

Type locality

Black Sea, Karantinnaya Bay, Sevastopol

Other localities

Black Sea, Streletskaya Bay, Sevastopol; Black Sea, Martynova Bay, Sevastopol; Black Sea, Kerch Strait (Naberezhnoe); Black Sea, Kazachja Bay, Sevastopol

Description

Based on holotype, 5 paratypes and 24 specimens from D. pastinaca in the Black Sea and 6 specimens from the same host in the Sea of Azov. Worms mid-size, craspedote, apolytic, 56—255 mm (123 ± 8.3; n = 36) long, 300—2200 (957 ± 57; n = 36; n = 72) wide. Proglottids 495—1803 (981 ± 48; n = 36) in number. Scolex large, 800—3130 (1472 ± 76; n = 33) long, 1100—2800 (1832 ± 71; n = 33) wide, tetrabothridiate (fig. 1, 5). Myzorhynchus absent. Apical sucker absent. Bothridia 110—1500 (836 ± 50; n = 33; n = 34) long, 200—1500 (622 ± 40; n = 33; n =51) wide; posteriorly bifid; with numerous marginal loculi, each 50—100 (59 ± 3; n = 31) long, 30—100 (55 ± 3; n = 31) wide; with short and wide pedicel, 100—500 (279 ± 19; n = 32; n = 37) long, 100—500 (242 ± 18; n = 32; n = 34) wide (fig. 6). Cepalic peduncle indistinct, short, 200—680 (460 ± 22; n = 36) long, 280—900 (546 ± 23; n = 36) wide. Lateral excretory ducts 10—70 (35 ± 2; n = 36) in diameter. Immature proglottids rectangular, 20—200 (117 ± 7; n = 36; n = 48) long, 280—1550 (688 ± 35; n = 36; n = 49) wide (fig. 2). Mature proglottids trapezoid, almost square 130—630 (315 ± 18; n = 36; n = 41) long, 550—1760 (1166 ± 45; n = 36; n = 39) wide. Terminal proglottids 330—2200 (1027 ± 86; n = 35; n = 40) long, 630—2200 (1207 ± 46; n = 36; n = 39) wide (figs 4, 8). Mature proglottid with 51—98 (83 ± 2; n = 36; n = 43) testes. Testes round, 30—130 (57 ± 3; n = 36; n = 41) in diameter, median, arranged in two layers; post-poral testes absent (fig. 2, 4, 8). Cirrus-sac pyriform or spherical, 50—300 (204 ± 12; n = 36; n = 38) long, 40—270 (158 ± 10; n = 36) wide (fig. 3, 7). Cirrus armed with spinitriches. Total length of everted cirrus 800—850 (833 ± 17; n = 3), of inverted 220—750 (482 ± 23; n = 34; n = 44) (fig. 4). Vas deferens 10—100 (61 ± 5; n = 36; n = 38) in diameter, coiled, extending anteriorly to cirrus-sac, displaced to poral side in mature proglottids; seminal vesicle absent. Genital pores lateral, 15—57 % (32 ± 2; n = 36; n = 44) of proglottid length from posterior end, irregularly alternating. Vagina extending from Mehlis’ gland anteriorly, initially median, strongly wriggle, then lateral to cirrus-sac in mature proglottids, opening anterior to cirrus-sac in genital atrium; vaginal sphincter absent. Genital atrium simple, tubular, 50—300 (110 ± 9; n = 36) long, 30—200 (91 ± 7; n = 36) wide (fig. 3, 7). Ovary near posterior end of proglottids, median, H-shaped, tetralobed in cross-section; lobes asymmetrical. In mature proglottids, ovary lobes surrounding excretory ducts, extending almost to lateral margin of proglottid, separating vitellarium from posterior end of proglottid. Aporal ovary lobe 100—650 (268 ± 27; n = 36) long, 110—700 (329 ± 21; n = 36) wide, poral lobe 100—600 (250 ± 25; n = 36) long, 100—600 (312 ± 20; n = 36) wide (fig. 4, 8). Ovicapt at posterior margin of isthmus, large, spherical or oviform, 50—200 (84 ± 5.4; n = 36; n = 39) in diameter. Mehlis’ gland 20—200 (61 ± 8; n = 32) wide, invisible in some proglottids. Uterus ventral to vagina, extending from isthmus to median line of proglottid, not reaching its anterior end (fig. 4, 8). Vitellarium follicular; follicles numerous, 10—90 (43 ± 4; n = 36) in diameter in mature proglottids (fig. 2, 4, 8); in 2 lateral fields, 100—720 (246 ± 19; n = 36; n = 39) wide, each consisting of one dorsal and one ventral row of follicles, between which excretory ducts passes; extending from anterior end of proglottid to anterior margin of ovary, not interrupted at level of genital atrium, becoming thin, not extending posteriorly to ovary. Eggs oval, 25—40 (36 ± 3; n = 4; n = 6) long, 20 wide (n = 4).

Remarks and Differential diagnosis

Remarks. Absence of apical sucker is considered as a main differential character of the new genus. For the proof of this fact, the living specimens of Cairaeanthus were studied. So far as the marginal loculi of C. ruhnkei are small and the apical suckers may be only slightly larger than the marginal loculi, that makes their recognition difficult, especially on fixed material (e. g. in many species of Anthocephalum), movements of bothridia in the living specimens were examined. Additional structures on the bothridia were not found in both alive and fixed specimens.
Differential diagnosis. Cairaeanthus ruhnkei sp. n. differs from all known species of the closely related genus Anthocephalum, namely A. gracile (Wedl, 1855), A. centrurum Ruhnke, 1994, A. alicae Ruhnke, 1994, A. cairae Ruhnke, 1994, A. duszynskii Ruhnke, 1994, A. kingae Ruhnke, Seaman, 2009, A. michaeli Ruhnke, Seaman, 2009, A. lukei Ruhnke, Seaman, 2009 and A. currani Ruhnke, Seaman, 2009 in a number of characters. In addition to differences mentioned above in the generic diagnosis, C. ruhnkei can be distinguished from them by larger total length (56—255 mm vs 40—50 mm, 11—20 mm, 4—9 mm, 8—14 mm, 18—31 mm, 8.6—13 mm, 5.7—16.3 mm, 7.9—17.2 mm, 6.6—14.4 mm, respectively) and by more proglottids per worm (495—1803 vs 500—600, 35—65, 9—15, 80—110, 120—160, 33—50, 23—41, 28—56, 35—70, respectively). Moreover, C. ruhnkei differs from A. gracile in smaller number of testes (51—98 vs 100—130) and from A. cairae, A. kingae, A. michaeli, A. lukei and A. currani, on the contrary, in larger number of testes (51—98 vs 28—52, 30—37, 30—49, 32—48, 37—50 respectively).

Bibliography

First published in

Kornyushin V. V., Polyakova T. A. 2012. Cairaeanthus gen. n. (Cestoda, Rhinebothriidea), with the description of two new species from Dasyatis pastinaca in the Black Sea and the Sea of Azov. Vestnik zoologii. 46(4).P. 291-308.

Specimens in collection

	exemplar				found	in	host
15.C.2y.h	holotype	gravid		wholemount	2003-11-06	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
16.C.2y.p1	paratype	gravid		wholemount	2003-09-11	Black Sea, Streletskaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
17.C.p2y.p2	paratype	gravid		wholemount	2003-09-11	Black Sea, Streletskaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
18.C.2y.p3	paratype	gravid		wholemount	2003-09-11	Black Sea, Streletskaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
19.C.2y.p4	paratype	gravid		wholemount	2005-09-29	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
20.C.2y.p5	paratype	gravid		wholemount	2005-09-29	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
21.C.2y.p6	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
22.C.2y.p7	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
23.C.2y.p8	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
24.C.2y.p9	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
25.C.2y.p10	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
26.C.2y.p11	paratype	gravid		wholemount	2001-07-21	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
27.C.2y.p12	paratype	gravid		wholemount	2003-09-11	Black Sea, Streletskaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
28.C.2y.p13	paratype	gravid		wholemount	2003-09-11	Black Sea, Streletskaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
29.C.2y.p14	paratype	gravid		wholemount	2003-11-04	Black Sea, Martynova Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
30.C.2y.p15	paratype	gravid		wholemount	2003-11-06	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
31.C.2y.p16	paratype	gravid		wholemount	2003-11-06	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
32.C.2y.p17	paratype	gravid		wholemount	2003-11-06	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
33.C.2y.p18	paratype	gravid		wholemount	2005-09-29	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
34.C.2y.p19-20	paratype	gravid		wholemount	2005-09-29	Black Sea, Karantinnaya Bay, Sevastopol	Dasyatis pastinaca	Digestive tract
35.C.2y.p21	paratype	gravid		wholemount	2007-07-06	Black Sea, Kerch Strait (Naberezhnoe)	Dasyatis pastinaca	Digestive tract
36.C.2y.p22	paratype	gravid		wholemount	2010-09-23	Black Sea, Kerch Strait (Naberezhnoe)	Dasyatis pastinaca	Digestive tract
37.C.2y.p23	paratype	gravid		wholemount	2008-10-09	Black Sea, Kazachja Bay, Sevastopol	Dasyatis pastinaca	Digestive tract