Acanthobothrium pulidofloresae, Rodríguez-Ibarra & Violante-González & Monks, 2023

Rodriguez-Ibarra, Erick, Violante-Gonzalez, Juan & Monks, Scott, 2023, Two new species of Acanthobothrium Blanchard, 1848 (Cestoda, Onchoproteocephalidea) from Urobatis jamaicensis (Cuvier, 1816) (Elasmobranchii, Batoidea, Myliobatiformes) of the Mexican Caribbean, ZooKeys 1169, pp. 175-201 : 175

Acanthobothrium pulidofloresae sp. nov.

Figs 1 , 2

Type material.

Holotype (CNHE-11880), 1 paratype (CHE-P00145).

Type host.

Urobatis jamaicensis (Cuvier, 1816) ( Elasmobranchii: Myliobatiformes : Urotrygonidae ).

Type locality.

Isla Cozumel, El Paso de los Cedros, (20°21'57.74"N, 87°1'32.48"W), Quintana Roo, Mexico.

Site of infection.

Spiral valve.

Prevalence of infection.

14.28%

Etymology.

The species is named in honor of Dra. Griselda Pulido-Flores (Universidad Autónoma del Estado de Hidalgo, Centro de Investigaciones Biológicas, Hidalgo, Mexico) for her contributions to the academic training of the first author, and to knowledge of helminths, as well as for her friendship.

Diagnosis.

Acanthobothrium pulidofloresae sp. nov. is a Category 5 species. Body relatively long (41 mm long); scolex in a "clover leaf" configuration; apical suckers small, 12-13 (12.6 ± 2; 1; 3) long by 30-32 (31.33 ± 3; 1; 3) wide; strobila of 152-164 proglottids; short hooks, in claw configuration, 47-60 testes per proglottid; ovary symmetrical.

Description.

(Based upon measurements of one complete worm and one partial worm mounted on slides). Entire worm 41 mm long, greatest width at scolex (Figs 1 , 2 ), euapolytic; 152-164 (158; 2) proglottids per worm (Figs 1 , 2 ). Scolex consisting of scolex proper and cephalic peduncle; petaloid scolex proper, 288 long by 413 wide, maximum width of scolex at level of posterior end of posterior loculus (because of petaloid shape); floor of loculi surfaces and other surfaces of scolex without obvious microtriches (Figs 1A , 2A ). Bothridia attached to velum only from middle loculi to anterior end; velum flexible, when relaxed allows bothridia be in a position perpendicular to the rest of the scolex (i.e., petaloid scolex). Bothridia 475-515 (487 ± 32; 1; 4) long by 350-395 (378 ± 32; 1; 4) wide; each with three loculi separated by transverse septa, anterior region specialized, in form of muscular pad. Muscular pad 60-65 (62.5 ± 6; 1; 4) long, 114-126 (118 ± 8; 1; 4) wide, with apical sucker not well defined, 12-13 (12.6 ± 2; 1; 3) long by 30-32 (31.33 ± 3; 1; 3) wide. Each pad with one pair of bipronged hooks at posterior margin. Anterior loculus of bothridia 160-175 (170 ± 7; 1; 4) long, middle loculus 115-130 (123 ± 6; 1; 4) long, posterior loculi 75-100 (81 ± 13; 1; 4) long; ratio of lengths of loculus (anterior:middle:posterior) 1:0.7:0.5. Velum present between medial margins of bothridia at posterior margin of middle loculus (Figs 1A , 2A ).

Hooks with axial and abaxial prongs, hollow, with tubercle on proximal surface of axial prong; internal channels of axial and abaxial prongs continuous, smooth; base and anterior part of each hook embedded in muscular pad; handle short and thin, prongs short with tips turned inwards; abaxial prongs longer than axial prongs. Bases (handles) of medial and lateral hooks articulated to each other; lateral hooks relatively longer than internal hooks. Lateral hook measurements: A 36-42 (39 ± 3; 1; 4), B 48-60 (51 ± 7; 1; 4), C 57-68 (62.4 ± 8; 1; 4), D 76-87 (81 ± 7; 1; 4). Medial hook measurements: A’ 38-42 (40.8 ± 3; 1; 4), B’ 39-57 (36 ± 6; 1; 3), C’ 48-59 (52 ± 6; 1; 4), D’ 73-80 (76 ± 4; 1; 3) (Figs 1C , 2B ).

Cephalic peduncle 14.6 mm long, 220-317 (268 ± 69, n = 2) wide at mid-level; presence and type of microtriches not confirmed. Proglottids craspedote. Immature proglottids 230-500 (369 ± 81; 2; 8) long by 537-866 (708 ± 157; 2; 8) wide; mature proglottids, 537-1000 (753 ± 181; 2; 7) long by 476-769 (627 ± 137; 2; 7) wide; terminal mature proglottids 915-1793 (1196 ± 344; 2; 5) long by 415-633 (525 ± 105; 2; 5) wide. Gravid proglottids not observed. Genital pores lateral, irregularly alternating, 23-37% (29 ± 5; 2; 6) of total length of proglottid from anterior end in mature proglottids; in terminal mature proglottids, 22-43% (29 ± 9; 2; 5); genital atrium shallow. Testes oval in dorsoventral view, arranged irregularly anterior to ovarian lobes, two layers deep, 48-78 (64 ± 8; 2; 24) long by 24-59 (44 ± 8; 1; 24) wide (Figs 1B , 2E ). Testes 47-60 (52 ± 3; 2; 22) in total number, 24-33 (28 ± 2; 2; 22) aporal, 9-15 (11 ± 2; 2; 22) preporal, 10-16 (13 ± 2; 2; 22) postporal; no testes posterior to ovarian isthmus. Cirrus sac pyriform, curved posteriorly, 144-192 (166 ± 18; 2; 6) long by 68-96 (86 ± 13; 2; 6) wide in mature proglottid, efferent vessel is posterior in reference to the cirrus sac. Cirrus with spinitriches, eversible, globose. Vagina anterior to cirrus sac, vaginal wall glandular. Vaginal canal forms strongly marked loops, which descend slightly aporal to midline of proglottid; glandular cells extend along canal wall. Ovary with approximately symmetrical arms, follicular; poral lobe 210-500 (349 ± 99; 2; 12) long in mature proglottids, aporal lobe 218-510 (350 ± 95; 2; 12) long, extending to the posterior margin of cirrus sac in terminal proglottids (Figs 1B, D , 2E, F ). Shape of ovary in frontal view changes as proglottids mature: almost U-shaped in immature proglottids, inverted A-shaped in mature proglottids and inverted A- or V-shaped inverted in terminal proglottids; posterior arms of ovary are overlapping but appear joined. In mature and terminal proglottids, isthmus is located at middle of uterus. Mehlis’ gland posterior to isthmus; seminal receptacle not seen. Vitellarium follicular, consisting of two lateral bands; each band consisting of two columns of relatively large elongate oval follicles extending from near anterior margin of proglottid to near posterior margin, interrupted by vagina and cirrus sac; follicles 770-985 (842 ± 82; 2; 7) long, 60-100 (76 ± 19; 2; 7) wide. Uterus thin-walled, sacciform, extends from near anterior part of proglottid to near oӧtype. Excretory ducts lateral. Eggs not seen.

Remarks.

For U. jamaicensis , this is the second species of Acanthobothrium that has been described. Acanthobothrium cartagenensis was designated to Category 1, recently reassigned by Zaragoza-Tapia et al. (2020a). Acanthobothrium pulidofloresae sp. nov. belongs to Category 5 (sensu Ghoshroy and Caira 2001). Category 5 species have a total length> 15 mm (the new species is 41 mm long); number of proglottids> 50 proglottids (the new species has 152-164 proglottids); the number of testes per proglottids ≤ 80 (the new species has 47-60 testes per proglottid); and a symmetrical ovary (which the new species has).

Acanthobothrium pulidofloresae sp. nov. is easily distinguished from the other species of Category 5 because none of them has a scolex configuration called "clover leaf" ( Fyler and Caira 2010; Yoshida 1917); A. pulidofloresae sp. nov. also is distinguished from A. lintoni (2.5-22.62 mm) and A. paulum (4.5-20 mm) because it is longer (41 mm) and has a greater number of proglottids ( A. pulidofloresae sp. nov. has 152-164 long vs. A. lintoni = 5-60 and A. paulum = 16-20). The new species has smaller accessory suckers (12-13 long by 30-32 wide vs. 42-95 and 60-70, respectively); the bothridia are short (425-470 long vs. 389-720, and 500-800, respectively); much shorter hooks (total abaxial length 78-94 vs. 108-230, and 140-200, respectively). The new species has a greater number of testes (47-60 vs. 30-46, and 40-45, respectively) (Table 1 ).

Acanthobothrium pulidofloresae sp. nov. differs from A. amazonensis and A. quinonesi because it is relatively longer; however, A. regoi is approximately the same size (41 mm vs. A. amazonensis = 35, A. quinonesi = 25, and A. regoi = 45). These species also differ in the number of proglottids (152-164 vs. 75-100, 55-75, 87-120, respectively). The new species has a smaller accessory sucker (12-13 long by 30-32 wide vs. 85-107, 53-66, 61-102 in diameter, respectively). The hooks are shorter (total abaxial length 78-94 vs. 145-184, 100-142, 122-163, respectively) and the number of testes is less (47-60 vs. 50-72 in A. amazonensis , 43-62 in A. quinonesi , 47-70). The new species differs also from A. manteri because that species is slightly longer (the new species is 41 mm long vs. A. manteri 36-65 mm long. However, it is smaller than A. rajaebatis (41 mm long vs. 50-60 mm); has a smaller accessory sucker (12-13 long by 30-32 wide vs. 198 and 312 in diameter), shorter hooks (total abaxial length 78-94 vs. 175 and 305 and fewer testes per proglottids (47-60 vs. 55-74 and 58-85). Finally, it differs in the number of proglottids but there is some overlap in range (152-164 for A. pulidofloresae sp. nov. vs. 120-170 for A. manteri , and 80-120 for A. rajaebatis ).

The new species is different from A. franus (16-40 long, 68-141 proglottids) and A. psammobati (34 long, 90 proglottids) by being longer and having a greater number of proglottids. Acanthobothrium inbiorium (28-82 long, 156-223 number of proglottids) is longer and has a greater number of proglottids than A. pulidofloresae sp. nov. In addition, A. franus , A. psammobati and A. inbiorium differ by presenting accessory sucker larger in diameter ( A. pulidofloresae sp. nov. 12-13 vs. 60-159, 50, 20-75, respectively), bothridium longer ( A. pulidofloresae sp. nov. 425-470 vs. 627-1408, 605, 480-680, respectively). Acanthobothrium pulidofloresae sp. nov. and A. psammobati have hooks that are relatively equal in length ( A. pulidofloresae sp. nov., total abaxial length = 78-94 vs. A. psammobati = 91) and the hooks of the new species are shorter in length than those of A. franus (354-465) and A. inbiorium (95-120). Acanthobothrium pulidofloresae sp. nov. differs in the total number of testes (47-60) from A. franus (24-59), and A. psammobati (77), although there is some overlap with A. ibiorium (44-73).

Finally, A. angelae , A. confusum , A. edmondsi , A. giganticum , A. hispidium , and A. xiamenensis are worms with range in lengths of 50-240 mm vs. the 41 mm length of A. pulidofloresae sp. nov. Acanthobothrium angelae , A. confusum , A. giganticum , A. hispidium , A. maryanskii , A. xiamenensis have 250-500 proglottids, all more than A. pulidofloresae sp. nov. (152-164 proglottids), and A. edmondsi (47-86), A. goldsteini (60), and A. rhinobati (50) have a lesser number of proglottids than the new species. Acanthobothrium indicum has approximately the same number of proglottids as A. pulidofloresae sp. nov. (152-164 proglottids) but it is smaller in overall length (41 mm vs. 25 mm of A. indicum ), and the new species has less testes per proglottid than A. indicum (47-60 vs. 70 of A. indicum ). Acanthobothrium katherineae is shorter than the new species (21 vs. 41 mm of A. pulidofloresae sp. nov.), the anterior loculus is longer that of A. pulidofloresae (336-417 vs. 160-175, respectively), and it has a greater number of testes ( A. katherineae = 55-69 vs. A. pulidofloresae sp. nov. = 47-60). Acanthobothrium angelae , A. confusum , A. edmondsi , A. giganticum , A. goldsteini , A. maryanskii , and A. xiamenensis have an accessory sucker greater in diameter than that of A. pulidofloresae .

The following species of Acanthobothrium are described as having a clover-leaf scolex configuration: Category 3, A. robertsoni ; Category 4, A. adlardi , A. cestraciontis , A. dasybati , A. grandiceps , A. karachiense , A. ijimai , A. macrocephalum and A. pingtanensis ; A. mujibi has not been assigned to a category because of the lack of data in the description. Acanthobothrium cribbi is illustrated as having a scolex with bothridia that extend almost to have a petaloid scolex; however, the species is not described as having a clover-leaf scolex configuration ( Campbell and Beveridge 2002) (Table 1 ).

Acanthobothrium pulidofloresae sp. nov. differs from the ten species with a petaloid scolex in the following characteristics: A. robertsoni is longer than the new species (83 mm vs. 41 mm of A. pulidofloresae sp. nov.), has a greater number of proglottids (395 vs. 152-164), the scolex is larger (3000-3250 vs. 288), the accessory suckers are larger (104-152 vs. 12-13 long by 30-32 wide), the bothridia and loculi are longer (1840-2220 vs. 425-470), the hooks are longer in total abaxial length (133-208 vs. 84-90), and the number of testes is greater (116-163 vs. 47-60). Acanthobothrium adlardi has a greater number of proglottids (235 vs. 152-164), the scolex is larger (800-1500 vs. 288), the accessory suckers are reported as being absent, the bothridia (and loculi) are longer (1100-1500 vs. 425-470), the hooks are longer in total abaxial length (148-176 vs. 84-90), and the number of testes is greater (83-103 vs. 47-60). Acanthobothrium cestraciontis differs from the new species by being longer (282 mm vs. 41), the accessory suckers are reported as being absent, the hooks are longer in total abaxial length (270-290 vs. 84-90), and the number of testes is greater (120 vs. 47-60). Acanthobothrium dasybati differs by being longer (52 mm), less proglottids (100), the accessory suckers are reported as being absent, the hooks are longer in total abaxial length (130 vs. 84-90), and the number of testes is greater (90-100 vs. 47-60). Acanthobothrium grandiceps differs from the new species by being shorter (14-20 mm vs. 41 mm), having a greater number of proglottids (950 vs. 152-164), the accessory suckers are larger (200-210 vs. 12-13 long by 30-32 wide), the bothridia (and loculi) are longer (2200-2300 vs. 427-460), the hooks are longer in total abaxial length (165-180 vs. 84-90), and the number of testes is greater (110-130 vs. 47-60). Acanthobothrium karachiense is different from the new species by having a greater number of proglottids (278-293 vs. 152-164, the scolex is larger (1750-1790 vs. 288), the bothridia (and loculi) are longer (1290-1450 vs. 427-460), it has smaller hooks in total abaxial length (62-68 vs. 84-90), and the number of testes is greater (74-98 vs. 47-60). Acanthobothrium ijimai differs from the new species by having larger accessory suckers (100 vs. 12-13 long by 30-32 wide), the bothridia are longer (1600-1700 vs. 425-470), the hooks are longer in total abaxial length (90-110 vs. 84-90), and the number of testes is greater (100-130 vs. 47-60). Acanthobothrium macrocephalum differs from the new species by being longer (82-287 mm vs. 41), having a greater number of proglottids (209-1000 vs. 152-164), the scolex is larger (3000-3250 vs. 288), the accessory suckers are larger (146-308 vs. 12-13 long by 30-32 wide), the bothridia (and loculi) are longer (1230-2471 vs. 425-470), the hooks are longer in the total abaxial length (96-142 vs. 84-90), and the number of testes is greater (92-145 vs. 47-60). Acanthobothrium pingtanensis differs from the new species by being longer (150-160 mm vs. 41 mm), the scolex is larger (3200-3680 vs. 288), the accessory sucker is larger (320-340 in diameter vs. 12-13 long by 30-32 wide), and the total number of testes is greater (92-106 vs. 47-60). Acanthobothrium mujibi differs from the new species by having a larger scolex (750-800 vs. 288 of A. pulidofloresae sp. nov.), bothridia that are longer (930 vs. 427-460), smaller hooks in total abaxial length (58-76 vs. 84-90), and the number of testes is less (36-41 vs. 47-60). Finally, A. cribbi is different from A. pulidofloresae sp. nov. by being somewhat larger (50 mm vs. 41 mm), having a greater number of proglottids (200-300 vs. 152-164), larger accessory suckers (80-152 in diameter vs. 12-13 long by 30-32 wide), and a greater total number of testes (72-96 vs. 47-60).

Three other species cataloged as species inquirendae by Caira et al. (2012) are illustrated as having a clover-leaf scolex configuration: A. majumdari , A. tsingtaoensis , and A. zugeinensis . Acanthobothrium majumdari and A. zugeinensis can be considered to be in Category 3 based on the symmetry of the ovarian lobes, i.e., for A Acanthobothrium majumdari , which which was reported as "each lobe length 0.1 (0.07-0.11)" ( Pramanik and Manna 2010), and A. zugeinensis described as "ovary lobed 902-985 µm for 213-236 µm” ( Yang and Lin 1994). It is not possible to determine a possible category for A. tsingtaoensis . Acanthobothrium majumdari differs from the new species by being longer (60-67 mm vs. 41 mm), having a very wide scolex (4400-5100 µm; i.e.,"4.8 (4.4-5.1) mm") ( Pramanik and Manna 2010) vs. 288 long by 413 µm wide for the new species; the bothridia are longer (2000 µm vs. 425-470 µm), the hooks are smaller in A. majumdari (total hook length 70 µm vs. 78-94 µm), the handle is longer (51-55 µm vs. 36-42), the number of testes per proglottid in A. majumdari is greater (145-155 vs. 47-60), and A. majumdari is apolytic.

Acanthobothrium pulidofloresae sp. nov. differs from A. zugeinensis by being shorter (41 mm vs. 140-160 mm), having a shorter scolex (288 long by 413 µm wide vs. 2601 by 2506 µm, see Yang and Lin 1994), the bothridia are shorter (425-470 µm vs. 664-688 µm), the hooks are longer (78-94 µm total hook length vs. 68-75 µm), the length of the handle is shorter (36-42 vs. 51-55 µm). The new species differs from A. majumdari in the number of testes per proglottid (47-60 vs. 106-132) and it can be distinguished from A. majumdari because the latter species is acraspedote.

Figures

Figure 1. Acanthobothrium pulidofloresae sp. nov. A, C, D holotype (CNHE- 11880) B paratype (CHE-P 00145) A scolex B mature proglottid C pair of hooks D terminal mature proglottid. Scale bars: 75 μm (C); 400 μm (B, D); 500 μm (A).

Figure 2. Acanthobothrium pulidofloresae sp. nov. A-D, G holotype (CNHE- 11880) E, F paratype (CHE-P 00145) A scolex B pair of hooks C apical suckers with pads muscular D apical sucker E mature proglottid F terminal mature proglottid G complete tapeworm. Scale bars: 50 μm (B, D); 100 μm (C); 200 μm (A, E, F); 3 mm (G).