Cladorhiza mirabilis ( Ridley & Dendy, 1886 )

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 : 76-78

Cladorhiza mirabilis ( Ridley & Dendy, 1886)

Figure 11 , Tables 5 & 8

Trochoderma mirabile Ridley & Dendy, 1886: 344 .

Axoniderma mirabile Ridley & Dendy, 1886: 493 .

Axoniderma mirabile Ridley & Dendy, 1887: 97–98 , Pl. XX, Fig. 5 , Pl. XXI, Figs. 8 , 9 , 10 .

Axoniderma mirabile: Koltun, 1970: 187 , Fig. 13 , 5–8

Material Examined: Histological slides of Types BMNH 1887.5.2.141 and BMNH 1891.10.3.49: south of Easter Island, South Pacific, Station 291, H.M.S. Challenger, 27/x/1875; 39° 13’S, 118° 49’ W, 4115 m depth, red clay substrate.

Distribution: This species is presently known only from the South and North Pacific.

Description:

Growth form: Pedunculate erect, ‘crinorhizoid’ parasol-shaped with conical cap-shaped body with terminal papillae, perched on the end of a long slender stem, with numerous long filaments surrounding the body, basal attachment not recorded. Ridley & Dendy (1887) record the height of the specimen (with broken stem) as 54 mm.

Ectosomal skeleton: The ectosomal skeleton of the filaments consists of granular collagen membrane containing predominantly larger pseudoamphiasters embedded vertical to the axial bundles of styles, and interspersed with smaller unguiferate anisochelae ( Fig. 11 D ).

Endosomal skeleton: Axis of filaments cored by small bundles of 4-5 larger styles-mycalostyles and tracts of few smaller styles running parallel to the axis ( Fig. 11 D ). Axis of stem and body with thick multispicular bundles of styles-mycalostyles that appear to consist mainly of the larger size class, with single or a few larger styles projecting on the terminal papillae at right angles to the axis ( Fig. 11 E ), and a thick cortex encrusted with pseudoamphiasters and other microscleres.

Megascleres: Styles in two categories, very large styles-mycalostyles ranging up to 6mm in length (mostly broken in the histological slide of the lectotype), and thinner supporting styles up to 300 µm long and 5 µm wide. Both sizes are styles occur together in the stem and filaments.

Microscleres: Pseudoamphiasters (127-(191)-295 x 8-(13)-18 μm, n=50), with 4-6 alae. Anisochelae (31-(40)- 48 x 2-(4)-8 μm, n=50), Sigmas (88-(106)-114 x 2-(4)-5 μm, n=9).

Remarks: The redescription of C. mirabilis from its microscope slide type clarifies some uncertainties in the original measurements of spicules provided by Ridley & Dendy (1887), and its possession of larger and smaller categories of styles-mycalostyles as structural and supporting megascleres, respectively ( Table 8 ).

Koltun’s (1970) also records this species from the North Pacific, listing a range of measurements for anisochelae and pseudoamphiasters, although it is unclear in his reference to pseudoamphiasters (“sometimes up to 0.230 mm long”), whether he was referring to additional spicules he observed in his material, or referring to Ridley and Dendy’s (1887) measurements, or both. He noted his material only differed from the 2 specimens described by Ridley & Dendy in lacking sigmas.

Re-examination of the data from the holotype of C. hubbsi during this study also revealed the range of anisochelae to be: 23-31-35 μm, pseudoamphiasters: 120-(136)-153 μm, styles (in three classes, 4041-(5067)-7142 x 52-(71)-96, 3419-(4172)-5146 x 25-(61)-102, 1518-(2565)-3330 x 14-(44)-79 μm and sigmancistras: 75-(98)-121 μm. The shape of the parasol apparently diagnostic for C. hubbsi ( Lundsten et al. 2017: Fig. 6A ) has the same vertical orientation of the filaments as does C. mirabilis in Koltun’s (1970) Plate 6 figure 7. Consequently, it would be informative to re-examine the maximum dimensions of the pseudoamphiaster in Koltun’s (1970) specimen, which may show it to be conspecific with C. hubbsi , and thus, suggest a pan North Pacific distribution, or as it currently is, a North-South Pacific continuum.

Unfortunately, neither the holotype of C. hubbsi nor Koltun’s (1970) C. mirabilis was available for us to reexamine. Re-examination of the type of C. mirabilis under an SEM or using molecular techniques would also be useful. In any case, a population genetic approach based on fresh specimens from the North and South Pacific would test the connectivity between temperate Pacific Ocean waters both sides of the equator, and even both sides of the International Date Line.

Lundsten et al. (2017) appear to have misinterpreted Ridley & Dendy’s (1887) description, with the original description of C. mirabilis having a basal width of 6 mm, compared to 11 mm in C. hubbsi . The lateral processes in C. mirabilis were listed as about 31 mm by Ridley & Dendy (1887) and these compare to 42–51 mm in C. hubbsi by Lundsten et al. (2017).

Unfortunately, also, both Lenhert et al. (2005) and Lopes & Hajdu (2014) mistakenly list Ridley and Dendy’s (1887) measurements of the pseudoamphiasters in C. mirabilis as 23 µm instead of 230 µm.

Figures

FIGURE 5. A. Abyssocladia gliscofila sp. nov. Holotype QM G337499. B. Paratype QM G337492. C. Arcuate isochelae. D. Mycalostyle in the stem, filaments and basal holdfast. E. Magnified ends of the mycalostyle depicted in D. F. Style from the basal rootlets. G. Magnified ends of the style depicted in F. H. SEM showing the isochelae forming the ectosome over the mycalostyle bundles in the ectosome of the filaments.

FIGURE 6. Asbestopluma (Asbestopluma) maxisigma sp. nov. A. Anisochelae. B. Smaller size class of sigmas. C. Larger size class of sigmas. D. Large mycalostyle. E. Magnified ends of the mycalostyle depicted in D. F. Smaller subtylostyle. G. Magnified ends of the subtylostyle depicted in F. H. SEM showing the main stem longitudinal bundles of mycalostyles, as well as the major filaments buttressed with the large mycalostyles and the finer filaments composed of the subtylostyles I. Preserved holotype QM G337488.

FIGURE 8. Cladorhiza australis nov. sp. Holotype QM G337456.A. Stem of the sponge, showing the carpet of ‘cleistochelate’ anisochelae, and where they have been abraded off the underlying sheath of the ectosome. B. Close-up of the ‘cleistochelate’ anisochelae in A. C. Stem of the sponge with the ectosome peeled off the underlying mycalostyle bundle of the endosome. Note the mycalostyle contained in the ectosome. D. Two filaments, the uppermost filament has part of the ectosomal layer containing the ‘unguiferate’ anisochelae removed showing the mycalostyles in the endosome.

FIGURE 9. Cladorhiza poritea sp. nov. A. Tridentate ‘unguiferate’ anisochelae. B. Asymmetrical pseudoamphiaster. C. Variation in the alae of the pseudoamphiasters. D. Large mycalostyle. E. Magnified ends of the mycalostyle illustrated in D. F. Medium styles. G. Magnified ends of the style illustrated in F. H. Small styles. I. Magnified ends of the style illustrated in H. J. Section through the body and stem of the sponge with one of the filaments on the right. K. Paratype QM G337437. L. Holotype QM G337401. M. Paratype QM G337544.

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 11. A. Type of Axoniderma mirabile, BMNH 1887.5.2.141. B. Pseudoamphiaster and an unguiferate anisochelae. C. Pseudoamphiaster. D. Pseudoamphiaster and an unguiferate anisochelae. E. Sigma. F. Section through a filament showing the encrusting pseudoamphiasters in the ectosome and two sizes of styles in the endosome. G. Section through the end of the filament showing the external layer of pseudoamphiasters and the anisochelae in the endosome. H. Section through the body of the sponge showing the intersection of the stem and the filament rays, with encrusting pseudoamphiasters. I Section through the body with ectosome of pseudoamphiasters and anisochelae in the endosome.

FIGURE 13. Cladorhiza investigator sp. nov. Holotype QM G337458. A. External view of the filaments showing the tightly packed anisochelae in the ectosome. B. The ectosome of the filaments exposed revealing the mycalostyles in the endosome. C. The external surface of the stem showing the ectosomal plates formed by the mycalostyles and the almost alternate juxtaposition of the filaments. D. Internal T.S. of the stem showing the mycalostyles buttressing the filaments after they have emerged from the confused core. In addition it shows the longitudinal tracks of mycalostyles. E. Cross section of the stem, showing the nine radial filaments intersecting in the core of the stem, and the thin wedges of anisochelae and sigmas between these arms. F. Branching roots of the sponge, showing an almost absent ectosome, but the tight bundles of mycalostyles and three thin subtylostyles in the upper branch.

Tables

TABLE 8. A comparison of spicule dimensions (µm) of Cladorhiza mirabilis.

Species	Anisochelae	Pseudoamphiasters	Styles-mycalostyles	Sigmas
C. mirabilis Ridley & Dendy (1887) , (published measurements)	38	<230	3500	76
C. mirabilis type (re-examina- tion of type, this study)	31.3-(40.1)-48.2 x 2.0-(4.3)-8.3, n=50	127-(191)-295 x 8.3-(13.5)-17.8, n=50	Large: up to 6000 x 11 Small: up to 300 x 5	88-(106)-114 x 2.3-(3.6)-5.0, n=9
C. mirabilis Koltun (1970) , (published measurements)	33-38	88-(104)-230	3500	absent