taxonID	type	description	language	source
039A1C11FFACFFA4FF0CFDEDFB8C3341.taxon	diagnosis	Diagnosis. with characteristics of Theonellidae; ectosomal spicules as phyllo- to dichotriaenes; large choanosomal oxeas sometimes present; megascleres sometimes completely absent; microscleres as small, acanthose microrhabds only, sometimes curved slightly. Type-species. Theonella swinhoei Gray, 1868; by monotypy (Gray 1868).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA4FF0CFF7AFDD231E2.taxon	diagnosis	Diagnosis (after Pisera and Lévi 2002; Fromont and Pisera, 2011): polymorphic, choanosomal spicules as tetraclone desmas; ectosomal spicules as phyllo- to discotriaenes; large choanosomal oxeas sometimes present; megascleres sometimes completely absent (some Theonella); microscleres characteristically as small, acanthose microrhabds, sometimes centrangulate or with slight curve, sometimes as streptasters and microrhabds (Manihinea) or streptasters only (Racodiscula). Type-genus: Theonella Gray, 1868.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	description	Figs 1 – 4	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	materials_examined	Material examined. Holotype: QM G 329195 (= SBD 520375), Australia, Great Barrier Reef, inter-reef sea floor, south of Wreck Island Reef, 23.775 ° S 15.005 ° E, 41.3 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Gwendoline May, 13. Apr. 2004, epibenthic sled. Paratype: QM G 325567 (= SBD 518107), Australia, Great Barrier Reef, inter-reef sea floor, south of Wreck Island Reef, 23.375 ° S 151.975 ° E, 43.5 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Gwendoline May, 22. Apr. 2004, epibenthic sled.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	description	Description. based on examination of holotype and paratype; both specimens post-fixed in ethanol (70 %) after initial frozen storage. Growth form and gross morphology: sponge consists of very thin sheets, thickness ~ 50 µm; sheets encrust exclusively over single species of Tenagodus Guettard, 1770 (Gastropoda, Caenogastropoda, Siliquariidae); sponge forms mass with snails, cements Tenagodus shells, incorporates small amounts of algae, detritus and debris; Tenagodus shells in interior of mass appear non-live, shells at perimeter of mass sometimes contain live (at time of fixation) snails; mass incorporates Tenagodus of various ages, some tiny (<1 mm diameter), others mature (> 5 mm diameter); holotype mass measures ~ 5 × 7.5 × 3 cm (total mass, including shells) (Figs 1 A, 2 A – D). Colour: unknown in life; bright orange portions of sponge mixed with green algae and cream snail shells when frozen; colour retained in ethanol; stains ethanol pale golden yellow; yellow pigment greasy. Oscules: unobserved macroscopically in frozen and fixed material; visible microscopically, few, inconspicuous, shallow, discrete, elliptical, ~ 100 – 200 µm (length), distributed sparsely (Fig 3 A). Texture: difficult to determine due to inclusion of large volume of snail shells; sponge very soft, fragile, friable, granular, flaccid, limp, highly compressible, slowly resilient, spongy. Surface ornamentation: even, smooth. Ectosomal skeleton: indistinguishable from choanosome. Choanosomal skeleton: lax, vague; rigid skeleton entirely absent; skeleton consists only of confused arrangement of interstitial microscleres scattered throughout mesohyl; microscleres sparse in patches, distributed singularly, concentrated in other regions, forming dense carpet; collagen homogenous; occasional foreign megascleres (oxeas, regular triacts) incorporated into mesohyl (Figs 2 D, 3 A – C). Megascleres: nil. Microscleres: single category of microrhabd; microrhabds as highly spined microxeas, small, isodiametric, slender, fine, slightly curved, curvature irregular, tips sharply hastate, rhabd covered with numerous, fine, narrow, conical spines; spines as long or longer than rhabd width, project prominently from spicule shaft, arise perpendicular to axis; shaft straight, lacks torsion; dimensions 7.2 – 21.6 (14.6) × 2.5 – 3.4 (3.0) µm (Fig 3 D).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	etymology	Etymology. The specific epithet deliqua derives from the Latin deliquus (adjective), meaning lacking or wanting, and refers to the absence of desmas in this species. DNA sequence data. 1 COI barcode sequence was obtained for the holotype (GenBank Accession: KJ 494355; see Table 1); this sequence was 709 bp in length (including primers).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	biology_ecology	Ecology and distribution. Specimens of T. deliqua have, to date, been recovered only from the seabed of the inter-reef region of the Great Barrier Reef. Both specimens that we have examined have formed close associations with specimens of a single species of Tenagodus (Siliquariidae). Species of Tenagodus are known to occur only in obligate relationships with sponges (Bieler 2004), although species-specificity (between sponge and snail) of this obligate relationship has not been established (Pansini et al. 1999).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFACFFA7FF0CFC0CFE0A3190.taxon	discussion	Remarks. During examination of the holotype of Theonella deliqua n. sp., a dense mass of regular triactinal spicules (calthrops) was found; many of these calthrops were damaged and had broken rays (Fig 2 D). This mass of spicules was found lying in a valley between two Tenagodus shells and incorporated broken oxeas and other spicules (from the Family Didemnidae Giard, 1872 (Class Ascidiacea) and some possibly of holothurian origin). Another similar region, containing an accumulation of monactinal spicules, was found in the broken mouth of an empty Tenagodus shell (Fig 2 C). These regions overlie the thin sheets of T. deliqua, but are not incorporated intimately into the mesohyl of the sponge. The localisation of the spicule masses, in conjunction with their varied composition, indicates clearly that they are of foreign origin, and are not innate components. Further, T. deliqua itself encrusts closely over the surface of the Tenagodus shells, cementing only the shells together; detritus and debris appears to amass in rafts at low points where two shells are joined by the sponge. The microrhabds of the holotype and paratype of T. deliqua are of similar proportion, averaging 14.6 µm in length, and spanning a range from 7.1 to 21.6 µm. The range of spicule measurements was normally distributed (Fig. 4), although one spicule was detected which lay outside of this normal range, measuring only 6.7 µm. Although the range of microrhabd length is quite large, the majority of spicules ranges between 12 and 17 µm in length, and this size may be interpreted as “ typical ” for specimens of T. deliqua. Comments. Specimens of T. deliqua are readily distinguished from the type-species for Theonella, T. swinhoei, (and all other currently known species), by the absence of tetractinal megascleres. No desmas and no triaenes (phyllotrianes nor dichotriaenes) were observed in either specimen of T. deliqua that we examined. The spicule complement of T. deliqua comprises only microrhabds; this condition has not been observed to date in any recorded species of Theonella. Despite the lack of obvious morphological homologies with T. swinhoei and the other members of Theonella, membership of this new species to Theonella can be asserted confidently. The microrhabds of T. deliqua have a similar morphology to those observed in T. swinhoei and other species of Theonella. Although they are not noted directly in the original description by Gray (1868), we have examined material in the QM Porifera collection which is attributed to T. swinhoei, and observed that the microrhabds of T. swinhoei, like those in T. deliqua, are generally straight; although the rhabd may be bent, the central axis is free completely of any torsion, with fine, conical spines projecting perpendicularly from the spicule shaft. The lack of torsion is significant and shared between the microscleres of T. swinhoei and T. deliqua. The straightness of the rods is in contrast to the morphology seen in the streptasters of other astrophorids; this straight morphology justifies our use of the term “ microrhabd ”, rather than sanidaster or streptaster, to describe these microscleres. Further, and perhaps more significantly, the combination of the corroborating molecular analyses (see below) and the presence of shared chemotaxonomic characters (see below) offers strong support to the attribution of this new species to Theonella.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	description	Figs 1, 4 – 5	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	materials_examined	Material examined. Holotype: QM G 331427 (= SBD 513035), Australia, Great Barrier Reef, inter-reef sea floor, south-east of Guthrie Shoal, 23.095 ° S 151.875 ° E, 28.0 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 22. Sep. 2004, epibenthic sled.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	description	Description. Based on examination of holotype; specimen post-fixed in ethanol (70 %) after initial frozen storage. Growth form and gross morphology: s ponge consists of very thin sheets, thickness ~ 50 µm; sheets encrust over assorted non-specific substrates, cements a variety of unidentified broken gastropod shells, diatoms, broken coral debris into single mass; incorporates large amounts of filamentous algae, quartz sand and debris; holotype in three small ovoid masses, largest mass measures ~ 2 × 2 × 1 cm (total mass dimensions) (Figs 1 B, 5 A – B). Colour: unknown in life; pale orange to yellow portions of sponge mixed with green algae and dirty cream to brown snail shells, sand and debris when frozen; colour retained in ethanol; stains ethanol pale golden yellow; yellow pigment greasy. Oscules: unobserved macroscopically in frozen and fixed material; also unobserved microscopically. Texture: difficult to determine because of large amounts of debris in sponge mass; sponge soft, fragile, friable, granular, flaccid, limp, highly compressible, slowly resilient, spongy. Surface ornamentation: even, lightly granular. Ectosomal skeleton: indistinguishable from choanosome. Choanosomal skeleton: lax, vague; rigid skeleton entirely absent; skeleton consists only of confused arrangement of interstitial microscleres scattered throughout mesohyl; microscleres sparse in patches, distributed singularly, concentrated in other regions, forming moderately dense carpet; collagen homogenous, slightly granular in appearance; occasional foreign spicules (oxeas, rods from ascidians) incorporated into mesohyl (Figs 5 B – C). Megascleres: nil. Microscleres: single category of microrhabd; microrhabds as highly spined microxeas, robust, large, slightly curved, curvature irregular, tapering at ends, tips pointed, shaft covered with numerous, fine, short, conical spines, tips unspined; spines shorter than rhabd width, raised obviously from spicule shaft, arise perpendicular to axis; shaft straight, lacks torsion; dimensions 18.1 – 51.6 (37.5) × 2.2 – 4.4 (3.4) µm (Fig 5 D).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	etymology	Etymology. This species is named for Mary Kay Harper, College of Pharmacy, University of Utah, who is a close and extensive collaborator on the chemistry of these sponges, and whose painstaking chemical and morphometric observations on theonellids are helping to uncover suites of cryptic species. The chemical complement that Ms Harper has found in specimens of Theonella from the western Pacific may be of taxonomic importance and we honour her contribution to sponge chemotaxonomy in naming this species for her. DNA sequence data. 1 COI barcode sequence was obtained for the holotype (GenBank Accession: KJ 494356; see Table 1); this sequence was 709 bp in length (including primers).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	biology_ecology	Ecology and distribution. The single specimen of T. maricae was found in the inter-reef region of the Great Barrier Reef, within the Capricorn Bunker group.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFAFFFAAFF0CF9E9FE85322A.taxon	discussion	Remarks. We have, to date, found only one specimen of T. maricae in our collection. This species is difficult to isolate macroscopically, and it is likely that more specimens remain yet to be identified. Our examination of the holotype specimen shows that, like specimens of T. deliqua, large amounts of foreign sponge and non-sponge debris are incorporated into the structure of T. maricae (Figs 5 A – B). Large amounts of filamentous algae, or possibly filamentous bacteria, can be observed within the overall mass of the holotype. Measurements of the microrhabds of the holotype of T. maricae are in one class, with an average length of 37.5 µm and covering a range from 18.1 to 51.6 µm. This range follows a broadly normal distribution (Fig. 4), although it is skewed slightly towards the larger measurements, with the most frequent length approximately reaching 48.0 µm; the 95 % confidence interval for the median measurement is 35.9 – 40.2 µm. Detailed examination of the range of the spicules indicates that although the smallest recorded microrhabd measured 18.1 µm, the majority of the spicules is much larger, with the microrhabs typically exceeding 36 µm in length. Comments. The description of T. maricae adds a second species which does not contain megascleres to Theonella. As with specimens of T. deliqua, the specimen of T. maricae is characterised largely by the absence of any tetractinal or monactinal structural megascleres; both species possess only microrhabds as the native spicule complement. The holotype of T. maricae is distinguished readily, however, from the specimens of T. deliqua by the size and shape of the microscleres. The microrhabds of T. maricae are typically at least twice as large as those of T. deliqua (38 µm v. 15 µm). The spines along the rhabd are small and blunt, measuring less than the width of the shaft; this is in contrast to the long and sharply pointed spines along the microrhabds of T. deliqua. The overall composition of T. maricae incorporates a variety of foreign debris and seafloor rubble, further distinguishing it from T. deliqua, which encrusts almost exclusively over the live and dead shells of a single species of Tenagodus gastropod.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFA2FFADFF0CFD35FD7431DB.taxon	description	Figs 1, 4, 6	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFA2FFADFF0CFD35FD7431DB.taxon	materials_examined	Material examined. Holotype: QM G 329976 (= SBD 513022), Australia, Great Barrier Reef, inter-reef sea floor, south-east of Rock Cod Shoal, 23.7249 ° S 151.665 ° E, 34.3 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 20. Sep. 2004, epibenthic sled. Paratypes: QM G 329977 (= SBD 513042), Australia, Great Barrier Reef, inter-reef sea floor, west of Fairfax Island, 23.8849 ° S 152.105 ° E, 41.8 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Gwendoline May, 13. Apr. 2004, epibenthic sled; QM G 329978 (= SBD 505424), Australia, Great Barrier Reef, inter-reef sea floor, west of Old Reef, 19.4049 ° S 147.935 ° E, 42.0 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 27. Nov. 2003, epibenthic sled. Other material: QM G 329095 (= SBD 500449), Australia, Great Barrier Reef, inter-reef sea floor, east of Davies Reef, 18.8349 ° S 147.685 ° E, 62.9 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 22. Sep. 2003, trawl; QM G 329183 (= SBD 517180), Australia, Great Barrier Reef, inter-reef sea floor, north-west of Devlin Reef, 11.805 ° S 143.825 ° E, 37.9 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 5. Feb. 2005, trawl; QM G 329186 (= SBD 517310), Australia, Great Barrier Reef, inter-reef sea floor, north-west of Devlin Reef, 11.805 ° S 143.825 ° E, 34.7 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 4. Feb. 2005, trawl; QM G 329283 (= SBD 537784), Australia, Great Barrier Reef, inter-reef sea floor, east of Gladstone, 23.8349 ° S 151.585 ° E, 26.9 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 14. Nov. 2005, trawl; G 331398 (= SBD 500399), Australia, Great Barrier Reef, inter-reef sea floor, south-west of Little Broadhurst Reef, 19.045 ° S 147.3949 ° E, 14.9 m (depth), QM coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 21. Sep. 2003, epibenthic sled; QM G 331401 (= SBD 500654), Australia, Great Barrier Reef, inter-reef sea floor, west of Big Broadhurst Reef, 18.925 ° S 147.525 ° E, 17.2 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 22. Sep. 2003, epibenthic sled; QM G 331411 (= SBD 506498), Australia, Great Barrier Reef, inter-reef sea floor, south-west of Rudder Reef, 16.245 ° S 145.6149 ° E, 21.0 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 9. Oct. 2003, epibenthic sled; QM G 331426 (= SBD 512852), Australia, Great Barrier Reef, inter-reef sea floor, south-west of Lamont Reef, 23.625 ° S 151.875 ° E, 27.3 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 21. Sep. 2004, epibenthic sled; QM G 331429 (= SBD 513056), vAustralia, Great Barrier Reef, inter-reef sea floor, north-west of Tryon Island, 23.2249 ° S 151.7049 ° E, 28.0 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 22. Sep. 2004, epibenthic sled; QM G 331436 (= SBD 513964), Australia, Great Barrier Reef, inter-reef sea floor, north-east of Magnetic Island, 18.995 ° S 147.095 ° E, 35.0 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 26. Apr. 2004, epibenthic sled; G 331463 (= SBD 525255), Australia, Great Barrier Reef, inter-reef sea floor, east of Gladstone, 23.935 ° S 151.9333 ° E, 51.0 m (depth), QM coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 19. Sep. 2004, epibenthic sled; QM G 331662 (= SBD 524169), Australia, Great Barrier Reef, inter-reef sea floor, north-east of Mumford Reef, 22.1549 ° S 150.385 ° E, 79.2 m (depth), coll. CSIRO Great Barrier Reef Seabed Biodiversity Project on RV Lady Basten, 9. May. 2004, epibenthic sled; QM G 331964, Australia, Great Barrier Reef, inter-reef sea floor, south-west of Polmaise Reef, 23.6383 ° S 151.5025 ° E, 26.0 m (depth), coll. Vicki Hall, Northern Fisheries, Cairns (former Department of Employment, Economic Development and Innovation, Queensland Government), 22. Nov. 1999, epibenthic sled.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFA2FFADFF0CFD35FD7431DB.taxon	description	Redescription. Based on examination of holotype, 2 paratypes and 16 vouchers; all specimens post-fixed in ethanol (70 %) after initial frozen storage. Growth form and gross morphology: sponge consists of very thin sheets, thickness ~ 30 µm; sheets encrust over assorted non-specific substrates, cements a variety of unidentified broken gastropod shells, polychaete tubes, diatoms, broken coral debris into single mass; incorporates large amounts of quartz sand and debris, small amounts of filamentous algae; holotype mass measures ~ 4 × 5 × 3 cm (total mass dimensions) (Figs 1 C, 6 A – B) Colour: unknown in life; dark orange to yellow portions of sponge mixed with green algae and dirty cream to brown sand and debris when frozen; colour retained in ethanol; stains ethanol dark golden yellow; yellow pigment greasy. Oscules: unobserved macroscopically in frozen and fixed material; visible microscopically, few, inconspicuous, shallow, discrete, broadly elliptical, ~ 100 µm (diameter), distributed sparsely. Texture: difficult to determine because of large amounts of debris in sponge mass; mass friable, fragile; sponge soft, very fragile, friable, granular, flaccid, limp, highly compressible, slowly resilient, spongy. Surface ornamentation: even, smooth. Ectosomal skeleton: indistinguishable from choanosome. Choanosomal skeleton: lax, vague; rigid skeleton entirely absent; skeleton consists only of confused arrangement of interstitial microscleres scattered throughout mesohyl; microscleres sparse in patches, distributed singularly, concentrated in other regions, sometimes forming very dense carpet; collagen homogenous; occasional foreign megascleres (oxeas, regular triacts) incorporated into mesohyl (Figs 6 B – C). Megascleres: nil. Microscleres: single category of microrhabd; microrhabds as highly spined microxeas, small, isodiametric, robust, generally straight but rarely slightly curved, curvature irregular, tips rounded, rhabd covered with profuse, small, blunt, conical spines; spines shorter than rhabd width, raised obviously from spicule shaft, arise perpendicular to axis; shaft straight, lacks torsion; dimensions 8.1 – 21.5 (14.7) × 1.3 – 2.9 (2.2) µm (Fig. 6 D). DNA sequence data. 15 COI barcode sequences were obtained for specimens of T. xantha, including the holotype and both paratypes (GenBank Accession: KJ 494361 – KJ 494375; see Table 1); each of these sequences was 709 bp in length (including primers), except 4 which were shorter (KJ 494367: 597 bp; KJ 494365 & KJ 494369: 631 bp; KJ 494361: 634 bp (including primers )).	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFA2FFADFF0CFD35FD7431DB.taxon	biology_ecology	Ecology and distribution. Specimens of T. xantha have, to date, been found associated with the seabed only in the inter-reef areas of the Great Barrier Reef. Sutcliffe et al. (2010) draw attention to enormous biomass that specimens of T. xantha represent; they are distributed widely across the entire span of the Great Barrier Reef, extending from regions of low to high latitude, and are found in high densities in the inter-reef area. Sutcliffe et al. (2010) did not find any major correlation between the presence or prevalence of T. xantha and the composition of the underlying substrate, although specimens were not recovered commonly in areas with a high proportion of mud in the sediment.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
039A1C11FFA2FFADFF0CFD35FD7431DB.taxon	discussion	Remarks. We re-examined the holotype and both paratypes, in addition to 16 vouchers, of T. xantha using SEM and light microscopy. In no specimen were we able to observe any native megascleres; all specimens were found to contain only small, microspined microrhabds. The samples were morphologically homogeneous, with large amounts of debris incorporated into the structure of all specimens, including non-active polychaete tubes and shells, fragments of diatoms, and coralline and siliceous rubble. Small amounts of filamentous algae (or bacteria) were incorporated into the mass also. The measurements of the microrhabds were consistent among the samples we examined. The average microrhabd length was 14.8 µm (range 8.1 to 21.5 µm); three outlier measurements were detected (7.0 µm, 23.2 µm and 24.1 µm). The lengths fitted a normal distribution, which was not skewed appreciably. The median spicule length was 14.6 µm; there were relatively few spicules which measured less than 13.1 µm. The majority of microrhabds reached lengths of between 13 and 17 µm. Comments. This species was attributed initially to Dercitus Gray, 1867 by Sutcliffe et al. (2010) based on their interpretation of the morphology of this species as comprising sanidasters and three-rayed calthrops (calthrops reported in 20 % of their samples). Van Soest et al. (2010) and van Soest (2012 c) classify D. xanthus within the subgenus Dercitus (Stoeba) Sollas, 1888. We have been unable to replicate the sighting of any native calthrops in the holotype or paratypes, nor in any other specimens we examined. We can confirm the common occurrence of broken calthrops distributed sporadically in several of the samples we investigated, however, in no specimen could these be interpreted as native; indeed, in one specimen of T. deliqua, dense rafts of non-native broken calthrops were found aggregated in portions of the sponge mass of this species also (as noted above). The geometry of regular calthrops and triods and the thickness of the rays of these megascleres may make these particular spicule morphologies exceptionally robust; the tumbled edges, however, support their foreign origins. The absence of calthrops, and the interpretation of the microscleres as microrhabds, rather than sanidasters, renders the placement of this species within Dercitus unjustified. We interpret the morphology of this species as being consistent with other megasclere-lacking species of Theonella, and this interpretation is supported by DNA-based studies (see below); based on these data, we designate this species within Theonella, as T. xantha (Sutcliffe, Hooper and Pitcher, 2010) n. comb. Morphologically, specimens of T. xantha are very similar to those of T. deliqua and T. maricae, however, they may be distinguished by the shape of the microrhabds and ecological characteristics. Specimens of T. xantha are recognisable immediately from those of T. maricae by the size of the microrhabds; the spicules of T. maricae are more than twice as long as those of T. xantha. Discrimination between T. xantha and T. deliqua is subtler; boxplots comparing the microrhabd lengths (Fig. 4) show that the range of lengths of the microscleres of both species are broadly equivalent. The microrhabds of T. xantha, however, are more robust in appearance than those seen in T. deliqua. The spines along the shaft of the microrhabds of T. xantha are bluntly conical and generally shorter than the width of the rhabd. Contrastingly, the microrhabds of T. deliqua are less robust in appearance, being slender and bearing sharply pointed spines, which are longer than the length of the underlying rhabd. Structurally, T. xantha, like T. maricae, consolidates the seabed substrates and cements a variety of rubble types, however, these two species can be distinguished from T. deliqua by this characteristic, which contrasts the aggregation of only one species of Tenagodus shell by specimens of T. deliqua.	en	Hall, Kathryn A., Ekins, Merrick G., Hooper, John N. A. (2014): Two new desma-less species of Theonella Gray, 1868 (Demospongiae: Astrophorida: Theonellidae), from the Great Barrier Reef, Australia, and a re-evaluation of one species assigned previously to Dercitus Gray, 1867. Zootaxa 3814 (4): 451-477, DOI: http://dx.doi.org/10.11646/zootaxa.3814.4.1
