Acanthobothrium kurdistanense, Maleki & Malek & Palm, 2019

Maleki, Loghman, Malek, Masoumeh & Palm, Harry W., 2019, Five new species of Acanthobothrium (Cestoda: Onchoproteocephalidea) from the long-tailed butterfly ray, Gymnura cf. poecilura (Elasmobranchii: Gymnuridae) from the Persian Gulf and Gulf of Oman, Zootaxa 4609 (2), pp. 289-307 : 293-294

Acanthobothrium kurdistanense n. sp.

( Figs. 6–9 , 16–21 )

Type host: Gymnura cf. poecilura , Long-tailed butterfly ray ( Myliobatiformes : Gymnuridae )

Type locality: Gulf of Oman (25° 11´N, 60° 33´E – 25° 25´N, 57° 43´E) , Iran.

Additional localities: None.

Site of infection: Spiral intestine.

ZooBank registration: The Life Science Identifier (LSID) urn:lsid:zoobank.org:act:870DA0E5-25D8-4D92-B683-57746516A811 .

Deposited material: Holotype ( ZCUOK. 122), 5 paratypes ( ZCUOK 123 – ZCUOK 127 ), 5 paratypes ( ZUTC Platy. 1336– ZUTC Platy. 1340), 1 SEM voucher ( ZUTC Platy. 1341).

Prevalence of infection: 3.3% (1 of 30 individuals examined).

Etymology: The new species is named after University of Kurdistan where the first author is working on helminth parasites.

Description: Based on whole mounts of 11 mature worms, 1 scolex examined with SEM, and a whole mount of its voucher. Worms 1.13–2.58 mm (2.1±0.4; 11; 11) long, greatest width at scolex; 11–17 (14±1.8; 11; 11) proglottids per worm; worms euapolytic. Scolex consists of scolex proper and short cephalic peduncle. Scolex proper with 4 bothridia, 225–326 (265±30; 11; 11) long. Bothridia free posteriorly, 318–403 (363±34; 11; 11) long by 103–153 (128±16; 11; 11) wide; each with 3 loculi separated by two transverse septa, and specialized anterior region in form of muscular pad; muscular pad 62–98 (81±12.9; 11; 11) long by 80–114 (94±9.2; 11; 11) wide, rounded in shape, consisting of apical sucker and 1 pair of hooks at posterior margin; accessory sucker 25–42 (33±5.2; 11; 11) long by 38–47 (41±3.3; 11; 11) wide; anterior loculus with two lappets at posterolateral margins, 135–185 (162±17.8; 11; 11) long; middle loculus 36–64 (49±9.3; 11; 11) long; posterior loculus 58–95 (78±12.6; 11; 11) long; ratio of locular length (anterior: middle: posterior) 1: 0.24–0.35: 0.38–0.58; maximum width of scolex, 218–310 (268±25.9; 11; 11), at level of anterior loculus. Velum between pair of adjacent bothridia present.

Hooks bipronged, hollow, with tubercle on proximal surface of axial prong; internal channels of axial and abaxial prongs continuous, lateral and medial hooks equal in size; axial prongs slightly longer than abaxial prongs. Lateral hook measurements: A 36–48 (43±3.9; 11; 10), B 69–87 (80±6.9; 11; 5), C 53–63 (57±308; 11; 5), D 111–125 (118±5.4; 11; 5), E 94–109 (101±6.4; 11; 5), W 35–61 (47±12.3, 11; 5). Medial hook measurements: A´ 38–47 (42±3.7; 11; 10), B´ 62–94 (80±103; 11; 7), C´ 52–98 (63±17.2, 11; 6), D´ 110–125 (117±5, 11; 6), E´ 94–102 (98±3.4; 11; 5), W´ 37–52 (43±5.7; 11; 5). Bases of lateral and medial hooks approximately equal in length; hook bases embedded in muscular pad, bases covered with encrusted sclerotisation. Cephalic peduncle 36–82 (62±11.7; 11; 11) long by 97–148 (119±16.8; 11; 11) wide at mid-level.

Apical pad surface ( Figs. 17, 18 ) covered with papilliform filitriches. Proximal bothridial surfaces ( Fig. 19 ) covered with papilliform to slightly acicular filitriches and distal bothridial surface ( Fig. 21 ) covered with papilliform filitriches. Anterior region of strobila ( Fig. 20 ) covered with papilliform filitriches.

Proglottids acraspedote, protandrous. Immature proglottids 9–15 (12.3±1.9; 12; 10) in number; mature proglottids 1–2 (1.8±0.4; 12; 10) in number. Terminal mature proglottid 344–654 (547±105; 12; 11) long by 134–219 (167±22.8; 12; 11) wide, length: width ratio 2.3–4 (3.2±0.4; 12; 11): 1. Gravid proglottids not observed. Genital pores lateral, alternating irregularly, 13–22 % (16±2.9; 12; 11) of proglottid length from posterior end. Testes ir- regularly round to oval in dorsoventral view, 19–46 (32±7; 12; 15) long by 30–54 (40±7.2; 12; 15) wide, arranged in 2 regular columns anterior to ovary, 28–37 (32±2.6; 12; 15) in total number, post-vaginal testes absent, no testes posterior to ovarian field. Cirrus-sac narrow, oval in mature proglottid, extending anteriorly along poral arm of ovary, 83–136 (109±16.6; 12; 10) long and 30–50 (40±6.8; 12; 10) wide, containing coiled cirrus; cirrus expanded at base; most of cirrus length covered with spinitriches. Vas deferens in mid-part of mature proglottid. Vagina short, thick walled, sinuous, extending from o ӧtype along midline of proglottid to near anterior margin of poral lobe of ovary, then posteriorly following anterior margin of cirrus sac to common genital atrium; vaginal sphincter absent; seminal receptacle not seen. Ovary located in posterior third of proglottid, poral lobe displaced by cirrus sac, symmetrical, 86–216 (163±40.6; 12; 19) long, maximum width of ovary 53–112 (74±17.8; 12; 111), H-shaped in dorsoventral view, lobulated; reaching to posterior margin of testes; ovarian isthmus near mid-point of ovary; Mehlis’ gland posterior to ovarian isthmus. Vitellarium follicular, consisting of two lateral bands; each band consists of 2 columns of follicles, extending from anterior margin of testes to near anterior of ovary, interrupted by vagina, cirrus sac and ovary; Vitelline follicles irregular, 11–24 (16±3.9; 12; 15) long by 8–24 (17±4.3; 12; 15) wide. Uterus median, thin-walled, sacciform, extending from near anterior part of proglottid to near o ӧtype. Excretory ducts lateral. Eggs not seen.

Remarks: Acanthobothrium kurdistanense n. sp. is a Category 1 species, according to the categories for Acanthobothrium species determined by Ghoshroy & Caira (2001) i.e. less than 15 mm in total length, fewer than 50 proglottids, fewer than 80 testes, and an ovary with symmetrical lobes. There are currently 49 described Category 1 species (incl. A. omanense n. sp.). Acanthobothrium kurdistanense n. sp. differs from all but Acanthobothrium fogeli and A. omanense n. sp. in having papilliform filitriches on the proximal surfaces of the bothridia, the position of the genital pore in the posterior one-fifth of the proglottid, and the orientation of the cirrus sac parallel to the ovarian lobes. The new species can be distinguished from A. fogeli in having a smaller accessory sucker (30–52 vs. 60–108) and the possession of marginal lappets on its bothridia and from A. omanense n. sp. in its smaller size (1.1–2.58 vs. 2.6–5.2). In addition, A. kurdistanense n. sp. can be distinguished from A. omanense n. sp. and A. fogeli in the possession of a much shorter cephalic peduncle (36–82 vs. 125–315 and 128–230, respectively). This new species has more posterior genital pores (13–22%, also see remarks A. omanense n. sp.).

Figures

FIGURES 6–9. Acanthobothrium kurdistanense n. sp. 6. Scolex.Arrows show the marginal lappets. 7. Terminal mature proglottid. 8. Whole worm. 9. Hooks. Scale bars: Figs. 7, 9= 50 µm; Figs. 6, 8= 100 µm.

FIGURES 10–21. FIGURES 10–15. Scanning electron micrographs of Acanthobothrium omanense n. sp. 10. Scolex. Note: Small numbers on the scolex correspond to the figures showing higher magnification images of these surfaces, and white arrow tip show the marginal lappet. 11. Apical pad and hooks. 12. Surface of apical pad. 13. Proximal bothridial surface. 14. Distal bothridial surface. 15. Cephalic peduncle surface. FIGURES 16–21. Scanning electron micrographs of Acanthobothrium kurdistanense n. sp. 16. Scolex. 17. Apical pad and hooks. 18. Surface of apical pad. 19. Proximal bothridial surface. 20. Surface of anterior region of strobila. 21. Distal bothridial surface. Scale bars: Fig 16=100; Fig. 10=80 µm; Figs. 11, 17=40 µm; Figs 15, 20=2 μm; Figs. 12, 13, 14, 18, 19, 21=1 µm.