Acanthobothrium soniae, Zaragoza-Tapia, Francisco, Pulido-Flores, Griselda, Violante-Gonzalez, Juan & Monks, Scott, 2019

Zaragoza-Tapia, Francisco, Pulido-Flores, Griselda, Violante-Gonzalez, Juan & Monks, Scott, 2019, Two new species of Acanthobothrium Blanchard, 1848 (Onchobothriidae) in Narcineentemedor Jordan & Starks, 1895 (Narcinidae) from Acapulco, Guerrero, Mexico, ZooKeys 852, pp. 1-21 : 1

Acanthobothrium soniae sp. nov. Figures 1 A–E; 2 A–D

Type material.

Holotype (CNHE-11136), 3 paratypes (CNHE-11137), 3 paratypes (HWML-139978), and 1 paratype (CHE-P00081).

Other material examined.

Acanthobothrium bullardi Ghoshroy & Caira, 2001 ( CNHE– 4046, México) paratype; A. campbelli Marques, Brooks & Monks, 1995 ( CNHE– 3033, Costa Rica; HWML– 38546, Costa Rica) voucher and paratype; A. costarricense Marques, Brooks & Monks, 1995 ( CNHE– 3034, Costa Rica) 2 vouchers; A. dasi Ghoshroy & Caira, 2001 ( CNHE– 4044, México; HWML– 15549, 15550, 15551, México) 4 paratypes; A. franus Marques, Centritto & Stewart, 1997 ( CNHE– 3140, Costa Rica) paratype; A. inbiorium Marques, Centritto & Stewart, 1997 ( CNHE– 3138, Costa Rica) paratype; A. puntarenasense Marques, Brooks & Monks, 1995 ( CNHE– 4176, Costa Rica) paratype; A. rajivi Ghoshroy & Caira, 2001 ( CNHE– 4039, México) paratype; A. vargasi Marques, Brooks & Monks, 1995 (HWML 38545, Costa Rica).

Type host.

Narcine entemedor Jordan & Starks, 1895 ( Elasmobranchii: Torpediniformes : Narcinidae ).

Type locality.

Bahía de Acapulco (Playa Las Hamacas: 16°51'11"N, 99°53'59"W), Guerrero, México.

Site of infection.

Spiral intestine.

Quantitative descriptors of parasite populations ( Bush et al. 1997).

Prevalence= 9.0% (1 ray of 11 was infected); abundance = 0.73 (8 helminths in 11 rays); mean intensity = 8 (8 helminths in 1 infected ray).

Etymology.

The species is named in remembrance of Sonia Virginia Flores León, former player of the Pumas Club Women’s Basketball Team, UNAM, daughter of Virginia León-Règagnon and Martín Ignacio Flores-Carbajal and dear friend of SM and GP-F; she will not be forgotten.

Diagnosis.

Acanthobothrium soniae sp. nov. is a Category 2 species. It is small, with a range of 10-13 acraspedote proglottids. The testes are wider than long with a range of 31-47 testes per proglottid. The arms of the ovary are unequal (asymmetrical). Finally, this species also can be distinguished from similar congeners by total length, number of proglottids, diameter of accessory sucker, the length of the cirrus sac, number of testes per proglottid, and size of the hooks.

Description.

[Based on 5 complete worms and 3 partial specimens] Worms 2.9-6.7 mm (n = 5) long, euapolytic; 10-13 (n = 5) proglottids per worm. Scolex 380-420 (n = 6) long by 280-320 (n = 6) wide, with four bothridia. Maximum width of scolex at level of middle loculus (Figs 1A, 2A). Bothridia free posteriorly, tri-locular, 340-380 (n = 6) long by 140-160 (n = 6) wide, with anterior muscular pad (Figs 1A, 2A). Muscular pad 105-130 (n = 6) wide, with apical sucker 45-50 (n = 6) and one pair of bipronged hooks at posterior margin (Figs 1A, 2A). Anterior loculus of bothridia 175-205 (n = 6) long; middle loculus 60-90 (n = 6) long; posterior loculus 80-95 (n = 6) long (Figs 1A, 2A); loculus length ratio (anterior:middle:posterior) 1:0.38:0.46. Velum between medial margins of bothridia in dorsal or ventral pairs not seen (Figs 1A, 2A). Hooks bipronged, hollow, with tubercle on proximal surface of axial prong; internal channels of axial and abaxial prongs continuous, smooth, the base and anterior part of each hook embedded in musculature of scolex, tips of prongs free (Figs 1A, B, 2A). Bases (handles) of medial and lateral hooks articulate to one another (Figs 1B, 2A). Lateral hook measurements (n = 6): A 43-45, B 88-105, C 83-93, D 125-138; Medial hook measurements (n = 6): A’ 38-45, B’ 83-108, C’ 80-98, D’ 125-143. Cephalic peduncle 450-630 (n = 6) long by 70-95 (n = 6) wide, not all the cephalic peduncle is covered with prominent microtriches (Figs 1A, 2C). Scolex is covered with microtriches (Fig. 2B). Proglottids acraspedote. Immature proglottids 55-110 (n = 8) long by 60-115 (n = 8) wide, mature proglottids 225-800 (n = 8) long by 125-215 (n = 8) wide (Fig. 1C), terminal proglottids 585-1,425 (n = 7) long by 160-275 (n = 7) wide (Fig. 1D). Genital pore marginal, irregularly alternating, 56%-68% (n = 7) from anterior end of proglottid; genital atrium present (Fig. 1E). Testes in single layer, arranged in two irregular columns, one on each side of the uterus (Fig. 1C, D). Testes generally wider than long in mature proglottids, 25-63 (n = 8) long by 13-28 (n = 8) wide (Fig. 1C). Total number of testes 31-47 (n = 8), aporal 16-26 (n = 8), poral 15-21 (n = 8), preporal 11-17 (n = 8), and postporal 3-5 (n = 8); all testes located anterior to ovarian isthmus. Cirrus sac pyriform, extending anteriorly (Figs 1C, D, E, 2D), 55-90 (n = 6) long by 63-96 (n = 6) wide in mature proglottids, 85-140 (n = 6) long by 48-90 (n = 6) wide in termial proglottids. Cirrus armed.

Vagina extending laterally from common genital atrium, following anterior margin of cirrus sac, weakly sinuous posteriorly along medial line of proglottid to oötype (Figs 1C, D, E, 2D); vaginal sphincter absent. Seminal receptacle not seen. Ovary inverted A-shaped in frontal view in mature and terminal proglottids (Fig. 1C, D). Arms of ovary unequal (Fig. 1C, D); aporal arm always longer than poral arm. Aporal arm 78-275 (n = 7) long in mature proglottids, 243-625 (n = 7) long in terminal proglottids; poral arm 68-213 (n = 7) long in mature proglottids, 190-550 (n = 7) long in terminal proglottids and Mehlis’ gland posterior to ovarian isthmus. Vitellarium follicular form lateral bands, extending from near anterior margin of proglottid to near posterior margin of proglottid (Fig. 1C, D); follicles 15-23 (n = 6) long by 10-13 (n = 6). Uterus thick-walled, saccate, extending from anterior margin of proglottid to near posterior margin of proglottid. Excretory ducts laterally. Gravid proglottids and eggs not seen.

Remarks.

There are 42 Category 2 species (sensu Ghoshroy and Caira 2001) of Acanthobothrium that have been described worldwide. Of these, 17 species have been found in the Pacific Ocean, 14 of which are amphi-American (Table 1).

Acanthobothrium soniae sp. nov. is a Category 2 species (sensu Ghoshroy and Caira 2001): Category 2 species have a total length ≤ 15 mm (the length of A. soniae sp. nov. is 2.9-6.7 mm), a strobila made up of ≤ 50 proglottids ( A. soniae sp. nov. has 10-13 proglottids), the number of testes per proglottids ≤ 80 ( A. soniae sp. nov. has 31-47 testes per proglottid), and the arms of the ovary are asymmetrical.

As presented in Table 1, the new species can be distinguished from similar Category 2 species of Acanthobothrium that have been described from the Pacific Coast of the Americas (amphi-American species), and from others parts of Pacific Ocean by the measurements given in the Table 1. The total length of the new species (2.9-6.7 mm) is shorter than that of A. campbelli (0.99-1.8 mm). The number of proglottids of the new species (10-13) is less than that of A. annapinkiensis Carvajal & Goldstein, 1971 (15-26), A. cimari Marques, Brooks & Monks, 1995 (14-33), A. puntarenasense (23-27), A. guanghaiense Yang, Sun, Zhi, Iwaki, Reyda & Yang, 2016 (13-28), A. masnihae Fyler & Caira, 2006 (23-43), A. popi Fyler, Caira & Jensen, 2009 (14-20), and A. tetabuanense Reyda & Caira, 2006 (25-36), and the number of proglottids of the new species is greater than that of A. campbelli (3-6) and A. vargasi (5-7). The diameter of the accessory sucker of the new species (45-50) is shorter than that A. annapinkiensis (~120) and A. popi (50-88), and the diameter of the accessory sucker of the new species is longer that A. campbelli (16-38), A. coquimbensis Carvajal & Jeges, 1980 (16-44), A. olseni Dailey & Mudry, 1968 (24-34), A. puntarenasense (14-15), A. vargasi (22-41), A. guanghaiense (28-32) and A. popi (50-88). The length of the cirrus sac of the new species (55-90) is shorter than that of A. brachyacanthum Risen, 1955 (123-135), A. bullardi (113-175), A. cimari (148-180), A. coquimbensis (200-400), A. costarricense (100-236), A. dasi (100-153), A. olseni (96-168), A. puntarenasense (151-183), A. unilateralis Alexander, 1953 (150-160), A. guanghaiense (95-132), and A. popi (108-152). The number of testes per proglottid of the new species (31-47) is less than that of A. campbelli (15-23), A. rajivi (9-13), A. vargasi (6-12), and A. tetabuanense (6-12). Finally the measurements of the hooks of the 18 species can be found in Table 1.