Haliclona (Flagellia), Van Soest, 2017

Van Soest, Rob W. M., 2017, Flagellia, a new subgenus of Haliclona (Porifera, Haplosclerida), European Journal of Taxonomy 351, pp. 1-48 : 9-10

Flagellia subgen. nov.

urn:lsid:zoobank.org:act:B6ABC6E8-EF63-4D79-A636-B3348CC80D3A

Type species

Haliclona (Flagellia) indonesiae subgen. et sp. nov.

Etymology

The name is derived from the Latin word ‘ flagellum ’, meaning ‘whip’, which refers to the whip-like flagellosigma.

Diagnosis

Haliclona -like sponges possessing a spiculation of oxeas, flagellosigmas (asymmetrical sigmas with unequal length and unequal shape of inward curved endings) and symmetrical (normal-shaped) sigmas. Skeletal reticulation loosely organized, unispicular, paucispicular or polyspicular, bound by variable amounts of spongin.

Remarks

This subgenus shares with mainstream Haliclona species a skeleton in which the ascending spicule tracts are interconnected by single megascleres. There is usually no distinct detachable ectosomal skeleton, although tangential arrangement of the oxeas at the surface is common. The choanosomal skeleton tends to be very loosely organized, verging to confused. In that aspect it conforms most closely to species of the subgenus Gellius , but in that subgenus the sigmas are symmetrical and often angular. Although symmetrical normal sigmas are part of the spicule complement of the new subgenus, these are never angular. The habitus of members of the subgenus varies strongly, from small crusts to elaborate plates or arborescent forms. Association with other sponges or other sessile organisms appears common.

The subgenus is found all over the world’s oceans. The depth occurrence is wide, but so far is confined to coastal, continental platform and upper bathyal waters.

Ten species are recognized here, four of which are new to science, one is given a new name due to junior homonymy, and one remains unnamed due to limited available material. From the historical overview presented above it is likely that several more species will be found to be extant.

It would perhaps have been logical to choose Haliclona (Flagellia) flagellifera as the type species for the new subgenus as it is the most closely associated name to species belonging to Flagellia subgen. nov. (cf. the historical overview above). However, the holotype of H. (F.) indonesiae sp. nov. was collected

recently and is also quite large in size making subsampling for DNA sequencing a viable option for nearfuture phylogenetic studies of the position of Flagellia subgen. nov. in the order Haplosclerida .