Cladorhiza moniqueae, 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 : 82-84

Cladorhiza moniqueae sp. nov.

Figures 14 & 15 , Table 5

urn:lsid:zoobank.org:act:E4131AC2-95FD-4E25-8CBF-6A1ED16566D5

Material Examined. Holotype: QM G337496 off Newcastle , New South Wales, Australia, Station 65, 33° 26’ 27.6”– 33° 26’ 6.0” S, 152° 42’ 7.2”– 152° 39’ 54.0” E, 4280– 4173 m, Beam Trawl, Coll. Merrick Ekins on RV Investigator, Cruise IN2017_ V03 , Sample 65-162, 30/v/2017.

Etymology: Named after Monique Grol for her enthusiasm for SCUBA diving and the reef.

Distribution: This species is presently known only from the type locality off Newcastle, New South Wales, Australia, at abyssal depth.

Description:

Growth form: An erect pedunculate unbranched growth form with an aerodynamically shaped-body ( Figure 14 F ). The broken stem is 15 mm long and 0.7 mm wide, with basal attachment not collected. The main body is a horizontally aligned teardrop-shaped cushion 7 mm in length and width, accentuated by the medusoid-like tentacular filaments that trail in one direction only, as if the sponge was positioned in a strong unidirectional current. The six tentacular filaments are 15 mm long and 0.4 mm wide. The specimen did not have a basal attachment intact.

Colour: Tan in colour on deck and in ethanol.

Ectosomal skeleton: The ectosome of the pedunculated body consists of soft tissue encrusted with anisochelae and sigmas, and penetrated by both sizes of the mycalostyles producing a hispid surface ( Figure 15 B ). The ectosome of the stem is a very thick layer of anisochelae well packed perpendicular to the surface with only the large alae showing ( Figure 15 C ). This ectosome also contains sigmas. The ectosome of the tentacular filaments consists of the perpendicular orientated anisochelae and sigmas ( Figure 15 E ).

Endosomal skeleton: The endosomal skeleton of the stem consists of bundles of the large mycalostyles. The large mycalostyles from the stem extend into the main body along with the smaller mycalostyles where they form a thick radiating mass. Both types of mycalostyles are radially orientated that pierce the ectosome producing the hispid surface. Bundles of mycalostyles within the body also terminate into spherical bodies which may contain retracted filaments ( Figure 15A ). The endosomal skeleton of the tentacular filaments originates in the body with both type of mycalostyles, but apically becomes dominated by the smaller mycalostyles.

Megascleres: Mycalostyles are of two different types, large with very obvious central thickening (860-(1527)- 2440 x 17.9-(27.8)-40.1 μm, n=89), and a thinner and usually much shorter mycalostyle, (318-(898)- 1120 x 8.2- (13.1)-17.3 μm, n=43).

Microscleres: Tridentate unguiferate arcuate anisochelae with spatulate alae on the head and canine-like alae on the foot (49.0-(55.0)-60.0 x 25.1-(31.5)-36.2 μm, n=88). Large sigmas (165-(241)-289 x 6.6-(10.3)-15.3 μm, n=89), medium sized sigmas with slightly more contortion (71-(109)-166 x 2.4-(4.2)-6.3 μm, n=67), and small sigmancis- tras (36.3-(43.7)-49.0 x 1.2-(2.5)-3.6 μm, n=46).

Molecular data: The 28S sequence of QM G337496 is provided in the Sponge Barcoding Database under accession number SBD#2309 and the molecular difference to other congenerics displayed in Figure 3 .

Remarks: The external morphology of C. moniqueae sp. nov. is superficially similar to Chondrocladia (Chondrocladia) albatrossi Tendal, 1973 , from NE Brazil and Antarctica, as illustrated in Dressler-Allame et al. (2017, Fig. 4 ). However, the spicule composition is very different between both species, with the present species having unguiferate anisochelae and belonging to Cladorhiza . As appears to be the case with many carnivorous sponges, the growth form shows convergent evolution to adapt to these abyssal environments, even if their spiculation is divergent.

The spatuliferous upper alae seen on the anisochelae of C. moniqueae sp. nov. have a similar morphology to those of C. diminuta Lopes & Hajdu, 2014 , from the mesophotic off central Brazil, although all of the spicules in the latter species, and indeed the sponge itself as the name suggests, are very diminutive compared to those of C. moniqueae sp. nov. ( Table 5 ).

Similarly, the shape of the alae on the anisochelae also resemble those of Cladorhiza tridentata Ridley & Dendy, 1887 , from the Antarctic and comprehensively illustrated by Dressler-Allame et al. (2017, Fig. 10 ), but the lower alae of the anisochelae in the latter species are bifurcate (compared to canine-like in our new species). Other differences between the new species and C. tridentata include their very different growth forms (pedunculate versus encrusting, respectively), two size classes of sigmas, and presence of sigmancistras in C. moniqueae sp. nov. Cladorhiza schistochela Lévi, 1993 , from New Caledonia, which also has similar-shaped anisochelae, is cylindricallyshaped pedunculate, has much larger styles and anisochelae, smaller sigmas, and lacks sigmancistras. Cladorhiza nicoleae Castello-Branco et al., 2016 , from the mesophotic off central Brazil, also has similar anisochelae but they are much smaller than those of the new species, as are the sigmas and sigmancistras, and it has a spherical clubshaped body.

Figures

FIGURE 3. Maximum-likelihood phylogram of the DNA sequences of this study in comparison with other, published cornivorous sponges. Sequences from taxa of this study are in bold. Number at the branches are RAxML rapid bootstrap values. Numbers following the taxa are either QM registration numbers (QM G3xxxxx) or NCBI Genbank accession numbers. Scale bare are substitutions per site. Please note that the reconstruction does not represent a phylogeny as due to the variability of the 28SrRNA gene C-Region barcoding marker no unambiguous alignment is possible and clipping ambiguous sites would remove diagnostic characters for taxon distinction. The tree therefore indicates molecular differences rather than a robust phylogeny.

FIGURE 4. Abyssocladia annae sp. nov. A. Abyssochelae. B. Subtylostyle. C. Magnified ends of the subtylostyle depicted in B. D. Sigmancistra. E. Holotype QM G337611. F. SEM showing the abundant abyssochelae and sigmancistras in the ectosome and the underlying subtylostyles in the endosome.

FIGURE 10. Cladorhiza poritea sp. nov. A. Body of the sponge showing the upper and lower ectosomal surface with the endosomal radiating mycalostyles in between, there are two of the filaments which have been inadvertently folded back over the sponge body. B. Magnified body surface showing the abundant pseudoamphiasters, and the underlying anisochelae. C. Stem showing the encrusting pseudoamphiasters in the ectosome. D. L.S. stem interior with the pseudoamphiaster crust and the styles forming an outer sheath, and an internal cored of styles. E. External layer of the filaments with the anisochelae exterior to the pseudoamphiasters. F. L.S. filament interior showing a sheath of styles similar to the stem and a hollow core.

FIGURE 14. Cladorhiza moniqueae sp. nov. Holotype QM G337496. A. Unguiferate arcuate anisochelae. B. Large mycalostyle. C. Magnified ends of the mycalostyle illustrated in B. D. Smaller mycalostyle. E. Magnified ends of the mycalostyle illustrated in D. F. Holotype on deck. G. Large sigma. H. Small sigma. I. Sigmancistra.

FIGURE 15. Cladorhiza moniqueae sp. nov. Holotype QM G337496. A. T.S. through the sponge body showing the radial mycalostyles, with the stem underneath and the tentacular filaments leading off to the RHS. The arrows indicate the spherical bodies. B. Spherical bodies in the sponge body. The arrows indicate the spherical bodies. C. The exterior surface of the sponge body showing the echinating mycalostyles. D. Apical tip of the longest tentacular filament showing the organisation of the anisochelae and the underlying mycalostyles. E. Ectosomal surface of the stem. F. Endosome of the stem, showing the longitudinal arrangement of the large mycalostyles.