Three new species of Acanthobothrium Blanchard, 1848 (Cestoda:<br />Onchoproteocephalidea) in Stingrays (Dasyatidae) from the Pacific coast in Mexico

Abstract

Three new species of Acanthobothrium Blanchard, 1848 (Onchoproteocephalidea: Onchobothriidae) are described from Pacific coastal waters of Mexico. Based on four criteria for categorization of species of Acanthobothrium, the three new species belong to Category 2 species, characterized by their total length (&lt; 15 mm), number of proglottids (&lt; 50) and testes (&lt;80), and with asymmetrical ovary. Acanthobothrium ppdeleoni n. sp. from diamond stingray Hypanus dipterurus (Jordan &amp; Gilbert) is differentiated from congeners by a combination of characters including total length of the whole worms, size of the scolex and bothridia, length of the bases of the hooks and abaxial prongs, and the size of the cirrus sacs in mature proglottids. Acanthobothrium hypanus n. sp. and A. sinaloaensis n. sp. are described from longtail stingray Hypanus longus (Garman). Acanthobothrium hypanus n. sp. is differentiated by a combination of characters including size of the scolex and bothridia, diameter of the accessory sucker, length of the abaxial prongs, size of the cirrus sacs and testes in mature proglottids. Acanthobothrium sinaloaensis n. sp. is differentiated by a combination of characters including size of the scolex and bothridia, diameter of the accessory sucker, size of the cirrus sacs in mature proglottids, number of immature proglottids, number of testes, the length of the lobes of the ovary and the absence of velum between medial margin of bothridia. Thirteen species of Acanthobothrium have been reported previously from elasmobranchs from the Pacific coast of Mexico. In the present study, the number of species is elevated to 16.

Threatened, host-specific affiliates of a red-listed host: Three new species of Acanthobothrium van Beneden, 1849 (Cestoda: Onchoproteocephalidea) from the endangered white skate, Rostroraja alba (Lacépède)

“…Merely 7% (16 of 207) of all species of this genus have been reported from this region (see Zaragoza-Tapia et al, 2020a ). The new species from South Africa further increase the diversity of this already very diverse genus, with a new total of 210 valid species worldwide ( Caira and Jensen, 2017 ; Franzese and Ivanov, 2018 , 2020 ; Maleki et al, 2018 , 2019 ; Rodríguez-Ibarra et al, 2018 ; Zaragoza-Tapia et al, 2019 , 2020b ; Van Der Spuy et al, 2020 ). Unfortunately, as a result of observing a limited number of specimens from an endangered host species, no specimens were recovered from ethanol-fixed material in order to conduct a proper molecular analysis.…”

“…Helminths such as cestodes have co-evolved with their elasmobranch hosts for millions of years (see for instance Dentzien-Dias et al, 2013 ), thereby creating unique and very intimate host-parasite interrelationships ( Caira and Jensen, 2001 , 2014 ). Acanthobothrium van Beneden, 1850 (Cestoda: Onchoproteocephalidea II, sensu Caira and Jensen, 2017 ) is reported to be the most species-rich tapeworm genus known to infect elasmobranchs ( Maleki et al, 2015 ; Caira and Jensen, 2017 ), currently consisting of 207 valid species ( Caira and Jensen, 2017 ; Zaragoza-Tapia et al, 2019 , 2020b ; Van Der Spuy et al, 2020 ). Albeit already being an extremely diverse genus, Caira and Jensen (2017) state that an estimated 800 additional species of Acanthobothrium await future discovery.…”

Two new species of Acanthobothrium Blanchard, 1848 (Cestoda, Onchoproteocephalidea) from Urobatis jamaicensis (Cuvier, 1816) (Elasmobranchii, Batoidea, Myliobatiformes) of the Mexican Caribbean

“…For Digenea , Rodríguez-Ibarra et al (2011) and Zaragoza-Tapia et al (2013) . For Cestoda , Caira (1985a) , Monks et al (1996) , Caira and Zahner (2001) , Caira and Bruge (2001), Ghoshroy and Caira (2001) , Monks et al (2015b) , Monks et al (2015a) , Monks et al (2015c) , Rodríguez-Ibarra et al (2018) , Zaragoza-Tapia et al (2013) , Zaragoza-Tapia et al (2019) , and Zaragoza-Tapia et al (2020b) contributed new data.…”

“…Its members principally parasitize batoids and sharks ( Caira and Jensen 2017 ). Recent descriptions include 23 species, eleven from the greater Atlantic Ocean ( Franzese and Ivanov 2018 ; Rodríguez-Ibarra et al 2018 ; Franzese and Ivanov 2020 ; Van Der Spuy et al 2020 , 2022 ), six from the Persian Gulf and Gulf of Oman in the northwest Indian Ocean ( Maleki et al 2018 , 2019 ) and six from the Pacific Ocean ( Zaragoza-Tapia et al 2019 , 2020b ; Gallagher and Caira 2020 ). Of the 211 species, 17 species have been described from Mexican waters and three species known from other localities have been reported off México.…”

Host relationships and geographic distribution of species of Acanthobothrium Blanchard, 1848 (Onchoproteocephalidea, Onchobothriidae) in elasmobranchs: a metadata analysis

“…Acanthobothrium Blanchard, 1848 (Onchoproteocephalidea) is the most diverse genus that has been reported as parasite of the spiral intestine of elasmobranchs (Caira and Jensen 2017). At the present time, 201 species of Acanthobothrium are considered to be valid (Maleki et al 2013;Caira and Jensen 2017;Rodríguez-Ibarra et al 2018;Franzese and Ivanov 2018;Maleki et al 2019;Zaragoza-Tapia et al 2019, 2020. The genus consists of species that exclusively parasitize elasmobranchs as adults and, in many cases, individual species are thought to parasitize only a single species of elasmobranch (Caira 2011;Caira and Jensen 2017).…”