Cladorhiza australis Ekins & Erpenbeck & Hooper 2020, sp. nov.

Cladorhiza australis sp. nov.

Figures 7 & 8, Tables 5 & 6

urn:lsid:zoobank.org:act: 5C924F06-535C-418A-9328-F418F21ADB98

Material examined: Holotype: QM G337456 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 IN2017_ V03, Samples 6-158, 6-162.1 18/v/2017.

Paratype: QM G337474 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 IN2017_ V03, Sample 65-122.2, 30/v/2017.

Etymology: This species is named for its southern 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.

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 (G337456) 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 (G337474) 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 28S sequence of QM G337456 is provided in the Sponge Barcoding Database under accession number SBD#2314 and the molecular difference to other congenerics displayed in Figure 3.

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.

15 x 7Axis of stem cored by bundles of mycalostyles extending into the cushion- shaped body where they form a thick radiating mass, eventually piercing the ectosome and hispid surfacemycalostyles 1, 777-(1321)-1760 x 18-(28)-37 mycalostyles 2, 569-(929)-1120 x 9-(14)-19undifferentiatedunknowntridentate unguiferate anisochelae 49-(55)-6036-(44)-49 x sigmas 1, 1-(2)-4 165-(241)-289 x 7-(10)-15 sigmas 2, 71-(109)-166 x 2-(4)-6E. Australia, off New South Wales, abyssal

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117 x 3Axis of stem, rootlets and filaments cored by tight longitudinal bundles of mycalostyles of 3 size categoriesmycalostyles 1, 1240-(1509)-1880 x 18-(27)-41 mycalostyles 2, 600-(914)-1210 x 12-(16)-21undifferentiatedsubtylostyles 356-(624)-905 x 3-(6)-12unguiferate multidentate anchorate anisochelae 1, 20-(24)-28, anchorate anisochelae 2, 13-(17)-1936-(40)-44 x 2–3sigmas 36-(76)-152 Freycinet x 2-(3)-6 Peninsula, Tasmania, Australia, abyssal

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Large mycalostyles 1, 1510–3110 x 22–56, small mycalostyles 2, 426–1690 x 6–24undifferentiatedundifferentiated palmate & unguiferate anchorate anisochelae 1, 42–69 x 1.5–4 unguiferate anchorate anisochelae 2, 21–31 x1–331–46 x 2–4sigmas 1, 58–229 x 3–12 sigmas 2, 61–106 x 1–4Great Australian Bight, bathyal

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mycalostyles- strongyles 1, 710–1780 x 14.1–31.4 Acanthoxeas 162–233 x 7.9–17.3mycalostyles- strongyles 2, 260–780 x 6.3–20.4not presentanchorate anisochelae 20.4–29.8absentsigmas 37.7–45.5W coast Africa off Gabon– Congo, bathyal

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Pedunculate erect, long stem with large subspehrical body bearing abundant apical filaments, large basal rhizoids20–120 x 2unknownstyles 1, 551–2150 x 10–44 styles 2, 550–1100 x 10–17undifferentiatedundifferentiatedtridentate unquiferous anisochelae 33–8333–44sigmas 1, 33–111 sigmas 2, 33–44NW Pacific, Okhotsk Sea, mesophotic- bathyal

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100 x 2Axis of stems and branches cored by dense aggregation of mycalostyles, strongyles and occasional oxeas, filaments with few megascleresmycalostyles 280–420 x 8–14.4 strongyles 200–410 x 11.2–17.6 oxeas 300–440 x 6.4–9.6undifferentiatedundifferentiated Anchorate unguiferous anisochelae 17.6–24absentsigmas 75.2–88Mauritania, mesophotic

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200 x?Axis of stem with bundles of mycalostyles forming a solid core, axis of filaments made up of tightly packed mycalostyles perpendicular to the centre of the main skeletonmycalostyles 475-(670)- 799 x 9.4-(17.5)- 25.1undifferentiatedundifferentiated anchorate anisochelae 25.3-(32.7)- 37.746.6-(61.3)- 95.5112-(155)-182Shetland and NE Atlantic, bathyal

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18–35 x?Axis with longitudinal bundles of styles- subtylostylesstyles- subtylostyles 1400–2900 x 27–35 styles 1100–1300 x 24–25undifferentiated undifferentiated arcuate absent anisochelae 75–88sigmas 1, 150–200 sigmas 2, 45–65SW Indian Ocean off Cape TownDurban, abyssal

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styles- undifferentiated mycalostyles 465–1500 x 13–20 tylostyles 85–124 x 6undifferentiated palmate anisochelae 15–20absentabsentNorth Pacific, W Greenland, mesophotic

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125 x?Axis of stem with bundles of larger styles, surrounded by 2 smaller classes of styles in the flesh and filamentsfusiform styles 1, 935–1005 x 27 30fusiform styles 2, 775–650 x 20 styles 3, 580 x 13undifferentiated anisochelae 30–34absentsigmas 170–180 x 5Central Atlantic, Cape Verde, bathyal

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mycalostyles 1, 542-(975)- 1500 x 11-(19)-30 fusiform tylostyles 270-(303)- 365 x 8-(11)- 13mycalostyles 2, 1496-(1799)-2111 x 31-(36)-48undifferentiated tridentate anchroate anisochelae 23-(25)-27absentabsentSouth Atlantic, between Rio de la Plata and Tristan da Cunha, abyssal

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208–325 x 1–2.1Axis of stem cored by mycalostyles 1–3, filaments cored by mycalostyles 1&3, basal rhizoid cored by strongyles and mycalostyles 3mycalostyles 1, 3138–4850 x 49–75 mycalostyles 2, 1009–1501 x 15–29 mycalostyles 3, 242–452 x 13–17mycalostyles 1 & 3strongyles 421–1023 x 10–22 mycalostyles 3tridentate unguiferate anisochelae 33–3743–50absentOff N California, bathyal- abyssal

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undifferentiatedundifferentiated unguiferate tridentate anisochelae 22–23absentsigmas 28–70Prince Edward & Bouvet Islands, N Atlantic, bathyal

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55 x 0.5– 0.8Axis of stem and filaments cored by longitudinal bundles of stylesstyles 1, up to 3200 x 45–50 styles 2, 1 100–1400 x 12–15undifferentiatednot recordedtridentate unquiferous anisochelae 13–14absentabsentSouth China Sea, abyssal

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Pedunculate erect, spherical club-shaped body covered in large projections, filaments with swollen tips, short stalk, base missing14 x 2.5Axis of stem with tightly packed bundles of mycalostyles that continue into the center of the body, projections composed of a thinner central core of megasclere bundles, creating a radial skeleton in the body.mycalostyles 1, 1513- (2117)-2563 x 32.1-(46.4)- 56.7 mycalostyles 2, 407-(997)- 1358 x 7.1-(19.4)- 26.4undifferentiatedabsentanchorate anisochelae (tridentate) 50.3-(56.2)- 62.3absentsigmas 1, 233-(315)-384 sigmas 2, 126-(149)-187Wilkes Land & Weddel Sea, Antarctica, bathyal

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300 x 5–10Axis of stem and branches composed of tightly connected bundles of oxeas, producing a smooth rigid central skeletonoxeas 390-(615)-845 x 4.9-(22.0)- 38.9undifferentiatedundifferentiated multidentate anchorate anisochelae, 5 teeth, 22.6-(33.3)- 42.026.7-(43.4)- 55sigmas 100-(125)- 153Amphi- Atlantic, boreo-Arctic, mesophotic- bathyal

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larger mycalostyles ~1500 x 20smaller mycalostyles and stylessmaller styles ~63arcuate tridentate anisochelae ~38absentsigmas 110 x 4SW Pacific, NE of New Zealand, bathyal

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Stipitate erect, unbranched body, slender stem regularly encircled by long slender filaments in 4 rows in 2 vertical planes, stem anchored by several delicate rhizoid rootlets50 x 1Axis of stem cored by thick bundles of styles, filaments (“pinnae”) and rootlets cored by fewer stylesstyles 2000 x 19 (styles 650–2000 x 14–36) [styles 1, 2500–3000 x 24–50 styles 2, 500–1300 x 13–18]undifferentiatedundifferentiatedanisochelae 25 (anisochelae 18–27) [anisochelae 16–32]absentsigmas 130 x 7 (sigmas 1, 120–170 x 6–10 sigmas 2, 30–50 x 2–4) [sigmas 1, 100–180 sigmas 2, 50]Central S Pacific, N Pacific (Bering Sea) & NW Pacific, abyssal- hadal

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140 x1Axis of stem and body with longitudinal bundles of styles, peripheral skeleton made of bundles intersecting styles and other spicules near the surfacestyles 1, 2800–3000 x 30styles 2, 1100–1500 x 18styles 3, 500–700 x 8–12tridentate arcuate anisochelae 60–100absentsigmas 1, 100–125 sigmas 2, 50New Caledonia, mesophotic

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10–60 x 3unknownmycalostyles 1, 770–1210 x 21–32 styles 610–930 x 13–18undifferentiatedundifferentiated multidentate unguiferate anisochelae 33–4428–44sigmas 83–187NW Pacific, off Kuril Islands and Hokkaido, abyssalhadal

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150 x 1–5 Axis of stem and branches with bundles of mycalostyles forming a solid core, filaments cored by overlapping mycalostyles parallel to axial stemmycalostyles 430-(704)-918undifferentiatedundifferentiatedanchorate anisochelae, 5 teeth, 16.0- (23.4)-32.041.8-(49.5)- 58.1sigmas 31.4-(41.7)-53.6IcelandFaroe Ridge up to Svalbard, mesophotic- bathyal

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Small encrusting, cylindrical hemispheric dome attached directly to substrate, with cup- like apical depression6 x 12 (17–120 x 14)Ectosomal and endosomal skeletons a loose irregular reticulation of tylostyles, without obvious fibres, hispid surface from projecting tylostylestylostyles 700 x 15.5 (mycalostyles- subtylostyles 565–1163 x 9.5–17.0)not presentnot presentanisochelae 76 (tridentate anchorate anisochelae 52–80 fewer unguiferous anisochelae 50–80)absentsigmas 90 x 3.2 (sigmas 32–91)Prince Edward Islands & Weddell Sea, Subantarctic- Antarctic, bathyal- abyssal

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.