Lycopodina cassida, Ekins & Erpenbeck & Hooper, 2020

Ekins, Merrick, Erpenbeck, Dirk & Hooper, John N. A., 2020, Carnivorous sponges from the Australian Bathyal and Abyssal zones collected during the RV Investigator 2017 Expedition, Zootaxa 4774 (1), pp. 1-159 : 146

Lycopodina cassida sp. nov.

Figure 30 , Table 14

urn:lsid:zoobank.org:act:9422EA40-39B0-4EAB-A8E5-293B656EA9AD

Material Examined: Holotype QM G337416 , off Fraser Island , Station 119, Queensland, Australia 25° 12’ 21.6”– 25° 10’ 40.8” S, 153° 59’ 27.6”– 153° 58’ 44.4” E, 2247–2369 m, Brenke Epibenthic Sledge, Coll. Merrick Ekins on RV Investigator, Cruise IN2017_ V03 , Sample 199-118.1, 12/vi/2017.

Etymology: The species name refers to the helmet-like shape of the holotype, cassida, Latin for helmet.

Distribution. This species is presently known only from the type locality off Fraser Island, Queensland, Australia, at bathyal depth.

Description:

Growth form: The sponge is a delicate erect cup-shaped pedunculate sponge on a thick stem, less than 3mm high ( Figure 30 A ). With the remainder of a short stem supporting an expanding radial upper section of filaments, forming a calyx. Basal attachment was not collected. All of the holotype is now embedded on an SEM stub.

Colour: Pale cream on deck and in ethanol.

Ectosomal skeleton: The ectosomal skeleton is thin and membranous, and contains the anisochelae ( Figure 30 F–H).

Endosomal skeleton: The axis of the stem and the filaments consists of bundles of subtylostyles longitudinally arranged ( Figure 30 F–I).

Megascleres: Subtylostyles with a tapering point and a subterminal tyle several micrometres from the base (374-(536)- 1220 x 3.6-(6.9)- 15.2 µm, n=55) ( Figure 30 C–D).

Microscleres: Two sizes of anisochelae with differences in their lengths, but of similar morphology. The three upper alae are smooth and palmate, with the central one nearly fully detached and the two lateral ones completely fused to the fimbria. The lower alae are also nearly completely fused together, arcuate, with the frontal alae having three spines and the lower lateral alae each have two spines. The large anisochelae measure 16.0-(18.6)- 22.2 µm (n=66) long (width of the large alae 4.5-(6.3)-10.8 μm; width of the small alae 3.9-(5.2)- 6.7 µm) ( Figure 30 B ). The small anisochelae measure 8.7-(13.0)-15.1 μm (n=64) long (width of the large alae 2.9-(4.0)-5.4 μm; width of the small alae 2.2-(3.2)- 5.4 µm) ( Figure 30 E ).

Molecular data: It was not possible to get unambiguous molecular data from the type material

Remarks: The new species has a similar shape to that of Lycopodina communis ( Lopes & Hajdu, 2014) , but the new species lacks anisostrongyles, and has an additional larger class of anisochelae. This species also has some similarities to L. microstrongyla ( Lopes et al., 2011) ; however it differs markedly lacking microstrongyles and the very large styles present in the latter species. Lycopodina globularis ( Lévi, 1964) also has two similarly sized categories of anisochelae but they are of a very different shape to those of L. cassida sp. nov., and the new species is a calyx form, not globular-shaped as is L. globularis . This new species is also close to L. ecoprof ( Lopes & Hajdu, 2014) from Brazil, but differs in its pedunculate and radially expanding body with filaments, and lacking mycalostyles. This species differs from L. rhabdostylophora Dressler-Allame et al., 2017 , by the unusual shape of the anisochelae in the Weddell Sea species.

Figures

FIGURE 30. Lycopodina cassida sp. nov. A. Fixed holotype QM G337416. B. Large anisochelae. C. Subtylostyle. D. Magnified ends of the subtylostyle illustrated in C. E. Small anisochelae. F. Looking into the calyx bowl, with the filaments around the perimeter. G. Close-up of the base of the interior of the bowl. H. Filaments illustrating the anisochelae ectosome. I. Stem remains showing the subtylostyle axis of the endosome.