Two new species of Acanthobothrium Blanchard, 1848 (Cestoda: Onchoproteocephalidea) from rajiform batoids off Argentina

Abstract

Two new species of Acanthobothrium Blanchard, 1848 were collected from rajiform batoids along the coast of Argentina. They are Acanthobothrium carolinae sp. n. from Bathyraja magellanica (Philippi) and Acanthobothrium domingae sp. n. from Dipturus brevicaudatus (Marini). Both belong to category 1 and 2 because their total length is lower than 15 mm, they have fewer than 50 proglottids, fewer than 80 testes and a symmetric or asymmetric ovary. Acanthobothrium carolinae sp. n. differs from all congeners by the following combination of features: proglottid apolysis, hook morphology, microthrix pattern on the cephalic peduncle and distribution of the vitelline follicles. Acanthobothrium domingae sp. n. is unique in the combination of proglottid apolysis, total length, number of proglottids, hook and septal morphology, microthrix pattern on the cephalic peduncle, number and distribution of testes, cirrus sac length, distribution of the vitelline follicles and genital pore position. The discovery of these species increases the number of species of Acanthobothrium parasitising rajiform batoids off Argentina from one to three. All three species have a unique pattern of distribution of the gladiate spinitriches along the length of the cephalic peduncle, i.e., gladiate spinitriches being interrupted in a medial line both dorsally and ventrally.

Four new species of Acanthobothrium van Beneden, 1849 (Cestoda: Onchoproteocephalidea) from the spotted skate, Raja straeleni Poll, off the Western Cape, South Africa

“…Acanthobothrium microtenuis sp. n., as a category 2 species, differs from all except three of the category 2 species, along with those described from Franzese and Ivanov (2020), in its possession of postovarian testes. It resembles A. bobconniorum, A. microhabentes sp.…”

“…With the description of A. dolichocollum, we now recognise 51 species of Acanthobothrium assigned to category 2. Acan thobothrium dolichocollum presents testes located posterior to the ovarian isthmus, differentiating it from 45 of the recognised category 2 species, as well as the two additional species described by Franzese and Ivanov (2020). Acan thobothrium dolichocollum differs from the remaining five category 2 species, A. bobconniorum, A. popi, A. micro habentes sp.…”

“…For the purpose of a more reliable comparison, the latter is considered as a category 2 species in this study. Acanthobothrium microhabentes fea-tures the presence of testes located posterior to the ovarian isthmus, therefore clearly distinguishing it from 45 of the recognised category 2 species, as well as the additional two species recognised by Franzese and Ivanov (2020).…”

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)

“…Based on the hook measurements, A. umbungus n. sp. already differs from all but nine species, namely A. annapienkensis Carvajal et Goldstein (1971) , A. brayi Campbell et Beveridge (2002) , A. domingae Franzese et Ivanov, 2020 , A. gloveri Campbell et Beveridge (2002) , A. guanghaiense Yang, Sun, Zhi, Iwaki, Reyda et Yang (2016) , A. popi Fyler, Caira et Jensen (2009) , A. ppdeleoni Zaragoza-Tapia, Pulido-Flores et Monks, 2020, A. tasajerasi Brooks (1977) , and A. thomasae Campbell et Beveridge, 2002 . The hooks of both A. annapienkensis and A. domingae exceed that of A. umbungus n. sp.…”

“…can further be distinguished from A. minus , A. mooreae , A. sphaera , A. tasajerasi , and A. thomasae as they all have a shorter cephalic peduncle (<274 μm vs 291–834 μm, respectively), whereas A. chisholmae , A. cimari Marques, Brooks et Monks, 1995 , A. crassus Van Der Spuy, Smit et Schaeffner, 2020, A. dolichocollum Van Der Spuy, Smit et Schaeffner, 2020, and A. dujardini all have a longer cephalic peduncle (>1000 μm vs 291–834 μm, respectively). Furthermore, A. carolinae Franzese et Ivanov, 2020 , A. costarricense Marques, Brooks et Monks, 1995 , A. guanghaiense and A. puntarenesense all have a wider cephalic peduncle than that of A. umbungus n. sp. (>103 μm vs 62–97 μm, respectively).…”