A New Species of (Cestoda: "Tetraphyllidea") from the Taiwan Saddled Carpetshark, (Orectolobiformes: Parascylliidae).

Collection of cestodes from the Taiwan saddled carpetshark, , for the first time led to the discovery of n. sp. This species provided important insights into the identity of the heretofore monotypic -known previously only from the blind electric ray, , in New Zealand. The new species differs from in testis number, vitelline follicle and cirrus sac configuration, and in that it is hyperapolytic rather than euapolytic. Maximum-likelihood analysis of sequence data generated for the D1-D3 region of the gene not only confirmed this generic placement but also confirmed the close affinities between both species of and specimens previously referred to in the literature as new genus 7 n. sp. 1. Examination of limited material of the latter, including that of a second specimen from which partial sequence data were generated here, led to the realization that new genus 7 n. sp. 1 represents an undescribed species of , referred to here as n. sp. 2. All 3 species share bothridia divided into 1 anterior and 2 consecutive pairs of loculi. Given that n. sp. 2 parasitizes a member of the second and only other genus of parascylliid sharks (i.e., ), we predict that the 4 other species of and the 2 other species of are likely to host other species of . The factors that might account for the eclectic host associations of , which include a torpediniform ray and 2 species of orectilobiform sharks, are currently unclear. The compilation of diet data for these elasmobranchs and determination of the final intermediate hosts for these cestodes would be interesting avenues of further investigation given that cestodes are trophically transmitted between their intermediate and definitive hosts. The phylogenetic affinities of among elasmobranch cestodes remain unresolved.