Cladorhiza australis Ekins, Erpenbeck, and Hooper 2020
- Dataset
- Carnivorous sponges from the Australian Bathyal and Abyssal zones collected during the RV Investigator 2017 Expedition
- Rank
- SPECIES
- Published in
- 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): 1-159, DOI: 10.11646/zootaxa.4774.1.1
Classification
- kingdom
- Animalia
- phylum
- Porifera
- class
- Demospongiae
- order
- Poecilosclerida
- family
- Cladorhizidae
- genus
- Cladorhiza
- species
- Cladorhiza australis
description
Description: Growth form: An erect, unbranched, pedunculate ‘ crinorhizoid’, parasol-shaped sponge with filaments extending outwards, almost horizontally from the body (Figure 7 K). The filaments in the holotype (G 337456) are 13 mm long and 0.3 mm wide. The body of the sponge is a double cone, 8 mm in diameter across the centre. The stem of the sponge is 100 mm long, but is broken. The stem is flattened and 1 x 2 mm thick and terminates in basal roots. The body of the sponge is disc-shaped with a central papillate apex. The paratype (G 337474) is identical to the holotype except that it is smaller, in poorer condition, with the body 9.54 mm in diameter across the base of the cone, and the remaining bases of the filaments are only 3 mm in length. Colour: A tan coloured body with off white filaments and stem Ectosomal skeleton: The ectosomal skeleton, on the body and the filaments is covered on the external surface with tridentate ‘ unguiferate’ anisochelae (Figure 8 D). The ‘ cleistochelate’ anisochelae are uncommonly distributed in the sub-surface region of the ectosome supported by the medium sized mycalostyles. On the stem however, the outer layer of the membranous ectosome is covered by a uniform carpet of ‘ cleistochelate’ anisochelae (Figure 8 A, B) and this is also supported by the medium sized mycalostyles forming a protective sheath of the endosome (Figure 8 C). Endosomal skeleton: The endosomal skeleton of the body, the filaments, the stem and the roots consisting mainly of the larger mycalostyles in concentrated longitudinal bundles (Figure 8 C), but also includes the rarer medium and small mycalostyles. The large mycalostyles originate in the centre of the body and radiate out to become the horizontal filaments. Megascleres: The megascleres consist of three different forms of mycalostyles varying in their terminations, but all having a larger diameter in the centre of the spicule than at the ends. The largest mycalostyles have blunt ends, occasionally sinuous and oxeote in shape. The medium-sized and smaller, thin, supporting mycalostyles both have sharp tips. Dimensions are given in Table 6 Microscleres: The microscleres consist of abundant small anchorate ‘ unguiferate’anisochelae with three large alae and three smaller alae on each end, and less common larger multidentate anchorate anisochelae with upper alae overlapping lower alae (i. e. reminiscent of the ‘ cleistochelate’ condition). These ‘ cleistochelate’ anisochelae mostly have three upper alae, sometimes four, and three curved lower alae. Sigmas are rare, slightly contort, and consist of a single size class (Table 6). Molecular data: The 28 S sequence of QM G 337456 is provided in the Sponge Barcoding Database under accession number SBD # 2314 and the molecular difference to other congenerics displayed in Figure 3.
description
Figures 7 & 8, Tables 5 & 6 urn: lsid: zoobank. org: act: 5 C 924 F 06 - 535 C- 418 A- 9328 - F 418 F 21 ADB 98
discussion
Remarks: In addition to the ‘ unguiferate’ anchorate anisochelae common to many other species of Cladorhiza, C. australis sp. nov. has a second unique form of anisochelae that verges on the ‘ cleistochelate’ morphology which is not present in any of the other species (see Table 5). Lopes et al. (2011) proposed that similar to the chelae transformation series in myxillids (arcuate-anchorate-birotulate) (Hajdu et al. 1994), cladorhizids also appear to have a transformation series from arcuate isochelae-cleistochelae-abyssochelae. It is possible, therefore, that this ‘ cleistochelate’ anchorate anisochelae condition, as demonstrated in C. australis sp. nov., is similar through the progressive expansion of alae longitudinally until they touch or nearly touch each other (Lopes et al. 2011). Of the 44 known species of Cladorhiza only seven have ‘ parasol’ growth form (dubbed the ‘ crinorhiza’ morphological group of cladorhizids by Ridley & Dendy 1886): C. mirabilis (Ridley & Dendy, 1886), C. longipinna In addition to the unique anisochelae character described above, C. austalis sp. nov. differs from these in a combination of other characters (see Table 5). Cladorhiza australis sp. nov. differs from C. mirabilis, C. hubbsi, C. mexicana and C. poritea sp. nov. in lacking pseudoamphiasters. It differs from C. longipinna in its spicule sizes, in particular having smaller unguiferate anisochelae, larger mycalostyles in three size classes, and the possession of sigmas. Cladorhiza similis also has three size classes of mycalostyles but each with a smaller size range than those of C. australis sp. nov., and it also lacks sigmas. Cladorhiza corona has mycalostyles of approximately the same size range as C. australis sp. nov. distributed throughout all parts of the skeleton except in the ectosome, but has in addition (sub) tylostyles and sigmancistras in the ‘ crown’ (a structure that is apical to body and surrounded by the filaments), and short anisoxeas in the basal disc (which was not collected in our species). Similarly, C. kensmithi (also a parasol-shaped growth form with a ‘ crown’), has three size classes of mycalostyles of more-or-less the same size range as those of C. australis sp. nov., sigmancistras, and strongyles in its basal rhizoid holdfast. Finally, C. australis sp. nov. differs from C. poritea sp. nov. in lacking pseudamphiasters, but having sigmas in addition to unguiferate anisochelae as microscleres. Ridley & Dendy, 1886, C. similis (Ridley & Dendy, 1886), C. corona (Lehnert et al., 2005), C. hubbsi Lundsten et al., 2017, C. kensmithi Lundsten et al., 2017 and C. mexicana Lundsten et al., 2017. With the addition of the two new species described in the present work, C. australis sp. nov. and C. poritea sp. nov., the number of parasol-species increases to nine.
distribution
Distribution: This species is presently known only from the abyssal zone off Tasmania and New South Wales, East Coast of Australia, at abyssal depth.
etymology
Etymology: This species is named for its southern distribution.
materials_examined
Material examined: Holotype: QM G 337456 off Freycinet Peninsula, Station 6, Tasmania, Australia, 41 ° 37 ’ 32.0 ” – 41 ° 41 ’ 21.2 ” S 149 ° 33 ’ 5.4 ” – 149 ° 35 ’ 3.5 ” E, 4022 – 4052 m, Beam Trawl, Coll. Merrick Ekins on RV Investigator, Cruise IN 2017 _ V 03, Samples 6 - 158, 6 - 162.1 18 / v / 2017. Paratype: QM G 337474 off Newcastle, Station 65, New South Wales, Australia, 33 ° 26 ’ 27.6 ” – 33 ° 26 ’ 6 ” S, 152 ° 42 ’ 7.2 ” – 152 ° 39 ’ 54 ” E, 4280 – 4173 m, Beam Trawl, Coll. Merrick Ekins on RV Investigator, Cruise IN 2017 _ V 03, Sample 65 - 122.2, 30 / v / 2017.