A New Species of Waginella (Crustacea: Thecostraca Ascothoracida) Parasitic on a Stalked Crinoid From Tasman Sea, With Notes on Morphology of Related Genera

A new ectoparasitic ascothoracidan species has been discovered off northern Tasman Sea at a depth of 520 m. Single female, described herein as Waginela ebonita Kolbasov and Newman sp. nov. in the family Synagogidae Gruvel, 1905, was collected on the column of crinoid Metacrinus sp. This is the first study of a new form of Waginella to be based on the extensive use of both light and scanning electron microscopy to document the fine-scale external morphology. We studied the external morphology of other two species of Waginela, W. cf. axotremata and W. sandersi utilizing SEM and compared fine structures of all congeners. The genus Waginella represents a monophyletic taxon including at least 4 species having similar and unique morphology even on the ultrastructural level. Two species, W. cf. axotremata and W. cf. metacrinicola may represent at least two complexes of species. The morphology of an attachment apparatus in all species of Waginella suggests that they remain attached to the host for a considerable period of time. The lattice organs of Waginella have a unique structure distinguishing from all Thecostraca. Waginella ebonita sp. nov. is the second species of this genus known to harbor hyperparasitic cryptoniscid isopods representing parasitic castrators.

Automated summary

A new ectoparasitic ascothoracidan species, Waginela ebonita, was discovered at a depth of 520 m in the northern Tasman Sea. The study used light and scanning electron microscopy to document the fine-scale external morphology, revealing that Waginella represents a monophyletic taxon with at least 4 species having similar and unique morphology. The attachment apparatus morphology suggests that Waginella species remain attached to the host for a considerable period of time, and they have lattice organs with a unique structure distinguishing them from all Thecostraca.