Floriparicapitus, a new genus of lecanicephalidean tapeworm (Cestoda) from sawfishes (Pristidae) and guitarfishes (Rhinobatidae) in the Indo-West Pacific

Abstract

Floriparicapitus n. gen. (Cestoda: Lecanicephalidea), with F. euzeti n. gen. n. sp. as its type, is erected to house 3 new tapeworm species and 2 known species that are transferred to the new genus, all parasitizing sawfishes and guitarfishes (order Rhinopristiformes) in Indo-Pacific waters. The new genus differs from the 20 valid lecanicephalidean genera in its possession of a large scolex bearing a laterally expanded apical organ in the form of a rugose sheet in combination with a cirrus conspicuously armed with spinitriches and 3 pairs of excretory vessels. It most closely resembles Lecanicephalum, but differs conspicuously in its possession of 3, rather than 1, pair of excretory vessels. Two new species are described from sawfishes: Floriparicapitus euzeti n. sp., from Pristis clavata and Floriparicapitus juliani n. sp. from Pristis microdon, both from Australia. Floriparicapitus plicatilis n. sp. is described from the guitarfish Glaucostegus typus in Australia and the guitarfish Glaucostegus thouin in Malaysian Borneo. Two species formerly assigned to Cephalobothrium are transferred to the new genus; Floriparicapitus variabilis (Southwell, 1911) n. comb. from the sawfish Anoxypristis cuspidata in Sri Lanka and Floriparicapitus rhinobatidis (Subhapradha, 1955) n. comb. from the guitarfish Glaucostegus granulatus in India. The species from guitarfish differ conspicuously from those parasitizing sawfish in their possession of only 4 (F. plicatilis n. sp.) or 5 (F. rhinobatidis n. comb.) testes per proglottid, versus 9 or more in the 3 sawfish-parasitizing species. The latter 3 species differ from one another in scolex width, acetabular size, number of proglottids, and cirrus sac size. As it stands, the new genus appears to be restricted to a subclade of the Rhinopristiformes consisting of the sawfishes and species of Glaucostegus.