Patterns of Temporal and Spatial Variability of Sponge Assemblages

The primary goals of this thesis were to understand the spatial and temporal pattern of sponge assemblage variation over a variety of scales and investigate suitable monitoring methods for sponge assemblages. Sponges are an ecologically significant group in benthic marine communities, which are often ignored in current monitoring schemes. In chapter two the sponge biodiversity of New Zealand waters to 200m was examined using Taxonomic Distinctness measures initially to test if genera data could be used as a proxy for species level data in New Zealand waters. It was found that over 50% of the variation in genera biodiversity could be explained by location and depth around New Zealand. The study helped pinpoint where there were gaps in the New Zealand dataset, in particular for the West Coast of the South Island and also areas such as the Wellington South Coast, which had higher than expected values for Average and Variation Taxonomic distinctness measures, which as important areas where sponges should be monitored to make sure the high levels of biodiversity are protected. Taxonomic distinctness measures are useful for initially assessing how the biodiversity is distributed, especially when using a data set with uneven sampling effort, as it is robust to spatial and temporal bias in the majority of cases. However, there was an outlier to the genera data correlating well with the variation in species data in the case of a site dominated by Haliclona sp (Lyttelton Harbour). In chapters three and four the spatial and temporal variability of sponge assemblages of the Wellington South Coast were explored creating both a species list for the area and an understanding of how the sponge assemblage varies over time and space. There were significant differences in the sponges assemblages in similar habitat types over a scale of a few hundred metres. In addition, although all the sponge assemblages changed seasonally, the changes at each sampling site responded in a slightly different way most likely due to spatiotemporal variation in environmental conditions. A similar seasonal pattern was also observed in chapter five for sponge assemblages at Skomer Marine Reserve and this pattern was also clear when using morphological monitoring methods. This means that once a site has been mapped for biodiversity it is possible for some habitats to use morphological monitoring to identify if the sponge assemblage is changing significantly saving time and money. The results from Indonesia (chapter six) showed that although the sponge assemblages were changing significantly in the actual species present and their abundances, the proportion of diversity within each spatial level (quadrat, site and region) remained consistent when sampled at the same time each year throughout the five year study. In species rich assemblages there are a variety of life strategies that can respond differently to shifts in environmental conditions and contribute to ecological functioning in various ways. Various monitoring methods have been tested using sponge assemblages over various spatial and temporal scales in this thesis. Spatial, temporal and the interaction of spatial and temporal factors were all important for identifying significant assemblage differences at all of the sites. Further studies integrating the interaction of spatial and temporal factors into understanding monitoring data sets are vital to understand the patterns of assemblage variability and therefore incorporate into habitat management plans

Hexactinellida (Porifera) from the Drake Passage (Southern Ocean) with a description of three new species

Goodwin, Claire E., Berman, Jade, Janussen, Dorte, Göcke, Christian, Hendry, Katharine R. (2016): Hexactinellida (Porifera) from the Drake Passage (Southern Ocean) with a description of three new species. Zootaxa 4126 (2): 207-220, DOI: http://doi.org/10.11646/zootaxa.4126.2.

Carnivorous sponges (<i>Porifera, Demospongiae, Poecilosclerida, Cladorhizidae</i>) from the Drake Passage (Southern Ocean) with a description of eight new species and a review of the family <i>Cladorhizidae </i>in the Southern Ocean

This study reviews the taxonomy and biogeography of carnivorous sponges (family Cladorhizidae) in the Southern Ocean. Specimens were collected from seamounts in the Drake Passage by dredging and trawling and biogeographical information from other sources was compiled and reviewed. Eight new species of carnivorous sponges are described: Abyssocladia leverhulmei, sp. nov., Asbestopluma (Asbestopluma) sarsensis, sp. nov., A. (A.) gemmae, sp. nov., A. (A.) rhaphidiophorus, sp. nov., Asbestopluma (Helophloeina) keraia, sp. nov., Chondrocladia (Chondrocladia) saffronae, sp. nov., Cladorhiza scanlonae, sp. nov. and Lycopodina drakensis, sp. nov. Specimens of three previously described species, L. callithrix, L. calyx and A. (A.) bitrichela, were also found. These new records increase the number of known carnivorous sponge species in the Southern Ocean by more than a third. We demonstrate that the Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean and many of its species are highly endemic, with 70% found only in this region. Southern Ocean species represent close to 20% of all known carnivorous sponges. This study highlights the importance of seamount and bathyal benthic habitats for supporting the rich and endemic carnivorous sponge fauna of the Southern Ocean.</jats:p

RESIL RISK Northern Ireland: public perceptions of climate risks and adaptation in Northern Ireland

RESIL RISK Northern Ireland follows up from RESIL RISK, a research project that explored UK wide public perceptions of climate change and support for resilience building strategies. As part of the original project, a first survey was conducted with 1,401 British respondents in 2019 and a second (unpublished) survey repeated the survey during the global Covid-19 pandemic in October 2020. Furthermore the project informed a report summarising implications for effective climate communications, published in 2019 . While the original RESIL RISK maps out public perceptions of climate risks and support for adaptation strategies across the British public and provides insights into how these public perceptions are formed, it does not offer the opportunity to understand the unique situation of devolved UK administrations. Each UK region faces unique challenges when building regional resilience to the impacts of climate change and understanding how these translate into potential differences in public risk perception is essential for building climate resilient communities and nations. Northern Ireland is a post-conflict society where the most socially vulnerable experience disproportionate flood risks, and on average are exposed to higher expected annual damage costs in flood prone areas than any of the other UK nations . This project provides up to date insights into public perceptions of climate risks and support for adaptation strategies in Northern Ireland at a time when the country has ambitious Climate Legislation awaiting Royal Assent. Key research results and associated recommendations from RESiL RISK Northern Ireland are summarised in this report to support Government, local government and civil society action at a key time influencing legislation in progress and shaping the next NI Climate Change Adaptation Programme

Extreme phenotypic plasticity in metabolic physiology of Antarctic demosponges

Seasonal measurements of the metabolic physiology of four Antarctic demosponges and their associated assemblages, maintained in a flow through aquarium facility, demonstrated one of the largest differences in seasonal strategies between species and their associated sponge communities. The sponge oxygen consumption measured here exhibited both the lowest and highest seasonal changes for any Antarctic species; metabolic rates varied from a 25% decrease to a 5.8 fold increase from winter to summer, a range which was greater than all 17 Antarctic marine species (encompassing eight phyla) previously investigated and amongst the highest recorded for any marine environment. The differences in nitrogen excretion, metabolic substrate utilization and tissue composition between species were, overall, greater than seasonal changes. The largest seasonal difference in tissue composition was an increase in CHN (Carbon, Hydrogen, and Nitrogen) content in Homaxinella balfourensis, a pioneer species in ice-scour regions, which changed growth form to a twig-like morph in winter. The considerable flexibility in seasonal and metabolic physiology across the Demospongiae likely enables these species to respond to rapid environmental change such as ice-scour, reductions in sea ice cover and ice-shelf collapse in the Polar Regions, shifting the paradigm that polar sponges always live “life in the slow lane.” Great phenotypic plasticity in physiology has been linked to differences in symbiotic community composition, and this is likely to be a key factor in the global success of sponges in all marine environments and their dominant role in many climax communities

Reduced Diversity and High Sponge Abundance on a Sedimented Indo-Pacific Reef System: Implications for Future Changes in Environmental Quality

Although coral reef health across the globe is declining as a result of anthropogenic impacts, relatively little is known of how environmental variability influences reef organisms other than corals and fish. Sponges are an important component of coral reef fauna that perform many important functional roles and changes in their abundance and diversity as a result of environmental change has the potential to affect overall reef ecosystem functioning. In this study, we examined patterns of sponge biodiversity and abundance across a range of environments to assess the potential key drivers of differences in benthic community structure. We found that sponge assemblages were significantly different across the study sites, but were dominated by one species Lamellodysidea herbacea (42% of all sponges patches recorded) and that the differential rate of sediment deposition was the most important variable driving differences in abundance patterns. Lamellodysidea herbacea abundance was positively associated with sedimentation rates, while total sponge abundance excluding Lamellodysidea herbacea was negatively associated with rates of sedimentation. Overall variation in sponge assemblage composition was correlated with a number of variables although each variable explained only a small amount of the overall variation. Although sponge abundance remained similar across environments, diversity was negatively affected by sedimentation, with the most sedimented sites being dominated by a single sponge species. Our study shows how some sponge species are able to tolerate high levels of sediment and that any transition of coral reefs to more sedimented states may result in a shift to a low diversity sponge dominated system, which is likely to have subsequent effects on ecosystem functioning. © 2014 Powell et al

Sphaerotylus antarcticus Kirkpatrick 1907

&lt;i&gt;Sphaerotylus antarcticus&lt;/i&gt; Kirkpatrick, 1907 &lt;p&gt;(Figure 24)&lt;/p&gt; &lt;p&gt; &lt;b&gt;Specimens.&lt;/b&gt; BELUM. Mc 2015.597, BELUM. Mc 2015.606, BELUM. Mc 2015.607 and BELUM. Mc 2015.613 Grotto Island, Verdansky Base (Site 1) (65&deg;14.615&rsquo;S, 64&deg; 15.019&rsquo;W), depth 14&ndash;24 m; collected by C. Goodwin and E. Priestley, 16/02/2015; BELUM. Mc 2015.620 Grotto Island, Verdansky Base (Site 2) (65&deg;14.529&rsquo;S, 64&deg; 15.451&rsquo;W), depth 6&ndash;18 m; collected by C. Goodwin and E. Priestley, 16/02/2015; BELUM. Mc 2015.635 Rocks near San Martin Islands (65&deg;41.297&rsquo;S, 65&deg; 20.091&rsquo;W), depth 6&ndash;21 m; collected by C. Goodwin and E. Priestley, 17/02/2015; BELUM. Mc 2015.658; Detaille Island (Site 1) (66&deg;52.373&rsquo;S, 66&deg; 46.967&rsquo;W), depth 6&ndash;24 m; collected by C. Goodwin and E. Priestley, 18/02/2015; BELUM. Mc 2015.687 Rocks NW of Laktionov Island (65&deg;45.536&rsquo;S, 65&deg; 47.319&rsquo;W), depth 6&ndash;23 m; collected by C. Goodwin and E. Priestley, 22/02/2015; BELUM. Mc 2015.743 Rocks on west side of Pleneau Island (65&deg;06.407&rsquo;S, 64&deg; 04.417&rsquo;W), depth 8&ndash;12 m; collected by C. Goodwin and E. Priestley, 24/02/2015; BELUM. Mc 2015.812 and BELUM. Mc 2015.823; Nelson Island, South Shetland Islands (62&deg;59.607&rsquo;S, 60&deg; 33.601&rsquo;W), depth 7&ndash;18 m; collected by C. Goodwin and E. Priestley, 27/02/2015.&lt;/p&gt; &lt;p&gt; &lt;b&gt;External morphology.&lt;/b&gt; &lt;i&gt;In situ appearance&lt;/i&gt; (Figure 24A): Low oval lobe with densely hispid brown surface. From the lobe transluscent conical papillae, up to 3 cm in length, arise. These are yellow in colour but some are tinged brown.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Preserved appearance.&lt;/i&gt; Pale brown sponge. Columns visible in interior. Cortical layer about 0.5&ndash;1 mm thick. Ectosomal projecting spicules very dense, giving a fur like appearance. Project up to 5 mm. Smooth papillae visible but shrunken. Alcohol is yellow.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Skeleton&lt;/b&gt; (Figure 24C): From BELUM.Mc2015.635.&lt;/p&gt; &lt;p&gt;Choanosome formed of thick radiating columns of over 20 styles with sphaerotyles nearer the surface. These cross the cortex and form a dense and thick surface hispidation. The cortex is formed of a sub-cortical tangential layer of smaller cortical styles and a dense palisade of tylostyles. Some sphaerotyles project through the surface, either individually or in tufts.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Spicules:&lt;/b&gt; Measurements from BELUM.Mc2015.635.&lt;/p&gt; &lt;p&gt;Cortical and choanosomal styles (Figure 24D): 407(694)1342 by 8.8(13.4)22.0 &micro;m with very slightly tylote heads.&lt;/p&gt; &lt;p&gt;Sphaerotyles (Figure 24B):&gt; 3000 &micro;m long. Heads 20&ndash;23 &micro;m diameter, shaft 7&ndash;14 &micro;m diameter.&lt;/p&gt; &lt;p&gt;Small tylostyles of cortex and choanosome (Figure 24E): 116(135)155 by 5.0(6.4) 7.7 &micro;m Spear shaped tylotes with pronounced rounded heads below a constricted neck.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; Our specimens correspond well to the form and size range of spicules given in Plotkin &lt;i&gt;et al.&lt;/i&gt; (2017) taken from the lectoype and paralectotypes, although we have not divided the cortical and choanosomal styles into two categories (Styles 900&ndash;2900 by 20&ndash;41 &micro;m; Subtylostyles 240&ndash;630 by 8&ndash;20 &micro;m; Small tylostyles 100&ndash;150 by 5.5&ndash;7 &micro;m; exotyles 1000&ndash;8000 by 20&ndash;30 &micro;m). Morley &lt;i&gt;et al&lt;/i&gt;. (2016) note that in overwintering specimens of &lt;i&gt;S. antarcticus&lt;/i&gt; the papillae elongated and narrowed, and grew long filaments with asexual buds along their length.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Sphaerotylus antarcticus&lt;/i&gt; is very similar to &lt;i&gt;S. borealis&lt;/i&gt; from the Northern hemisphere. This led Koltun (1976) to assume they were subspecies of a single bipolar species. However, they can be distinguished by the sabre-like shape of the small tylostyles in &lt;i&gt;S. antarcticus&lt;/i&gt; (Plotkin &lt;i&gt;et al.&lt;/i&gt; 2017).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution.&lt;/b&gt; This is a widely distributed species in the Antarctic having been recorded from the Davis Sea, Adelie Land, Bellingshausen Sea, Weddell Sea (Sar&agrave; &lt;i&gt;et al.&lt;/i&gt; 1992) and the South Shetland Islands 20&ndash;60m (Desqueyroux-Fa&uacute;ndez 1989) in addition to the type locality Winter Quarters, McMurdo Sound, Ross Sea. It has been recorded from several shallow-water sites in the Bellinghausen Sea between 12&ndash;21m depth (New Rock and Cape Bellue near Palmer Base; Almirante Brown Base, Paradise Bay) and is locally very common in shallow depths on King George Island, South Shetlands (Hajdu &lt;i&gt;et al.&lt;/i&gt; 2016).&lt;/p&gt;Published as part of &lt;i&gt;Goodwin, Claire E., Berman, Jade &amp; Hendry, Katharine R., 2019, Demosponges from the sublittoral and shallow-circalittoral (&lt;24 m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics, pp. 461-508 in Zootaxa 4658 (3)&lt;/i&gt; on pages 501-502, DOI: 10.11646/zootaxa.4658.3.3, &lt;a href="http://zenodo.org/record/3376028"&gt;http://zenodo.org/record/3376028&lt;/a&gt

Mycale (Oxymycale) acerata Kirkpatrick 1907

&lt;i&gt;Mycale&lt;/i&gt; (&lt;i&gt;Oxymycale&lt;/i&gt;) &lt;i&gt;acerata&lt;/i&gt; Kirkpatrick, 1907 &lt;p&gt;(Figure 18)&lt;/p&gt; &lt;p&gt; &lt;i&gt;Synonomy:&lt;/i&gt; &lt;i&gt;Mycale acerata&lt;/i&gt; Kirkpatrick, 1907; &lt;i&gt;Mycale acerata var. minor&lt;/i&gt; Hentschel, 1914; &lt;i&gt;Mycale acerata var. sphaerulosa&lt;/i&gt; Hentschel, 1914; &lt;i&gt;Oxymycale acerata&lt;/i&gt; (Kirkpatrick, 1907).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Specimens.&lt;/b&gt; BELUM. Mc 2015.552 G&oslash;uvernoren Wreck, Enterprise Island (64&deg;32.407&rsquo;S, 61&deg; 59.884&rsquo;W), depth 8&ndash;19 m; collected by C. Goodwin and E. Priestley, 12/02/2015; BELUM. Mc 2015.604 Grotto Island, Verdansky Base (Site 1) (65&deg;14.615&rsquo;S, 64&deg; 15.019&rsquo;W), depth 14&ndash;24 m; collected by C. Goodwin and E. Priestley, 16/02/2015; BELUM. Mc 2015.617 and BELUM. Mc 2015.631 Grotto Island, Verdansky Base (Site 2) (65&deg;14.529&rsquo;S, 64&deg; 15.451&rsquo;W), depth 6&ndash;18 m; collected by C. Goodwin and E. Priestley, 16/02/2015; BELUM. Mc 2015.649 Rocks near San Martin Islands (65&deg;41.297&rsquo;S, 65&deg; 20.091&rsquo;W), depth 6&ndash;21 m; collected by C. Goodwin and E. Priestley, 17/02/2015; BELUM. Mc 2015.655 The Minnows, Prospect Point (66&deg;01.642&rsquo;S, 65&deg; 21.323&rsquo;W), depth 6&ndash;18 m; collected by C. Goodwin and E. Priestley, 17/02/2015.; BELUM. Mc 2015.660 Detaille Island (Site 1) (66&deg;52.373&rsquo;S, 66&deg; 46.967&rsquo;W), depth 6&ndash;24 m; collected by C. Goodwin and E. Priestley, 18/02/2015; BELUM. Mc 2015.690 Rocks NW of Laktionov Island (65&deg;45.536&rsquo;S, 65&deg; 47.319&rsquo;W), depth 6&ndash;23 m; collected by C. Goodwin and E. Priestley, 22/02/2015; BELUM. Mc 2015.697 and BELUM. Mc 2015.710 Vieugue Island (65&deg;38.758&rsquo;S, 65&deg; 12.540&rsquo;W), depth 10&ndash;22 m; collected by C. Goodwin and E. Priestley, 23/02/2015; BELUM. Mc 2015.731 Port Charcot, Booth Island (65&deg;03.853&rsquo;S, 64&deg; 01.868&rsquo;W), depth 6&ndash;16 m; collected by C. Goodwin and E. Priestley, 23/02/2015; BELUM. Mc 2015.780 Under Spiggot Peak, Orne Harbour (64&deg;37.755&rsquo;S, 62&deg; 33.018&rsquo;W), depth 5&ndash;21 m; collected by C. Goodwin and E. Priestley, 25/02/2015; BELUM. Mc 2015.807 Neptune&rsquo;s Bellows, Deception Island (62&deg;59.607&rsquo;S, 60&deg; 33.601&rsquo;W), depth 7&ndash;18 m; collected by C. Goodwin and E. Priestley, 26/02/2015; BELUM. Mc 2015.833 and BELUM. Mc 2015.836 Diomedea Island (62&deg;12.185&rsquo;S, 58&deg; 56.760&rsquo;W), depth 10&ndash;18 m; collected by C. Goodwin and E. Priestley, 01/03/2015.&lt;/p&gt; &lt;p&gt; &lt;b&gt;External morphology.&lt;/b&gt; &lt;i&gt;In situ appearance&lt;/i&gt; (Figure 18A): Lemon yellow, massive, sponge, individuals can be very large - some of our specimens were over 60 cm in diameter. Large specimens are composed of a series of fused mounds, often these bear terminal oscules. The surface of the sponge is covered in small nodules ~ 5 mm in diameter, giving it a bumpy appearance (Figure 18B).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Preserved appearance.&lt;/i&gt; Grey mass. Skeletal columns visible as distinct fibres ~ 0.5 mm across. Preserving alcohol coloured yellow.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Skeleton&lt;/b&gt;: Choanosomal skeleton plumo-reticulate formed of columns of oxea 10&ndash;20 spicules thick (Figure 18C). Ectosome is composed of a mesh of fibres 4&ndash;8 spicules thick (Figure 18D). Microscleres are abundant, the larger chelae form rosettes.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Spicules:&lt;/b&gt; Measurements from BELUM.Mc2015.780.&lt;/p&gt; &lt;p&gt;Oxeas (Figure 18E): 629(679)748 by 16(22) 27 &micro;m with abruptly pointed ends.&lt;/p&gt; &lt;p&gt;Anisochelae 1 (Figure 18H): 69(79) 86 &micro;m in rosettes. The lower alae bears a short, antenna-like, projection.&lt;/p&gt; &lt;p&gt;Anisochelae 2 (Figure 18I): 33(45) 55 &micro;m. The lower alae bears a single pointed tooth.&lt;/p&gt; &lt;p&gt;Microxeas (Figure 18F) 30(84)111 by 1.6(2.1) 2.6 &micro;m. Spindle shaped.&lt;/p&gt; &lt;p&gt;Tiny oxeas/raphides (Figure 18G): 6.6(7.1) 7.8 &micro;m.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; The spicule sizes reported for the type are oxeas 850 by 16 &micro;m, chelae 105 and 47 &micro;m, and trichodragmata 62 &micro;m, although the tiny oxeas are not mentioned&mdash;these were not obvious in all of our specimens. Specimens produced a lot of slime on collection. &lt;i&gt;Mycale acerata&lt;/i&gt; was very abundant, present at most of our sampling sites, often in large quantities. It is one of the dominant species on the Antarctic Peninsula (Kowalke 1998).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Mycale acerata&lt;/i&gt; is faster growing than many other Antarctic sponges and has been demonstrated to increase 43&ndash;67% in terms of wet weight in a year, because of this, it is thought to be able to compete successfully against many slower growing benthic species and may become spatially dominant in some benthic environments (Dayton &lt;i&gt;et al.&lt;/i&gt; 1974). Populations seem to be regulated by predation, particularly that of the asteroids &lt;i&gt;Perknaster fuscus&lt;/i&gt; Sladen, 1889 and &lt;i&gt;Acodontaster conspicuus&lt;/i&gt; (Koehler, 1920).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution.&lt;/b&gt; &lt;i&gt;Mycale acerata&lt;/i&gt; is common along the Antarctic Peninsula, and widespread around the Antarctic and sub-Antarctic (records from Wilheim II Coast, Wilkes Land, South Shetland Islands, Princess Ragnhild Coast, Lars Christensen Coast, Kerguelen, Macquarie Island, Bouvet Island, South Orkneys, South Georgia), as well as being recorded from the Falkland Islands, Chile and Argentina (Koltun 1964; Brueggeman 1998; Rios &lt;i&gt;et al.&lt;/i&gt; 2004; Hajdu &lt;i&gt;et al.&lt;/i&gt; 2016). It has been recorded from 10&ndash;761 m + depth (Brueggeman 1998).&lt;/p&gt;Published as part of &lt;i&gt;Goodwin, Claire E., Berman, Jade &amp; Hendry, Katharine R., 2019, Demosponges from the sublittoral and shallow-circalittoral (&lt;24 m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics, pp. 461-508 in Zootaxa 4658 (3)&lt;/i&gt; on pages 492-493, DOI: 10.11646/zootaxa.4658.3.3, &lt;a href="http://zenodo.org/record/3376028"&gt;http://zenodo.org/record/3376028&lt;/a&gt

Clathria (Clathria) priestleyae Goodwin & Berman & Hendry 2019, sp. nov.

&lt;i&gt;Clathria&lt;/i&gt; (&lt;i&gt;Clathria&lt;/i&gt;) &lt;i&gt;priestleyae&lt;/i&gt; sp. nov. &lt;p&gt;(Figure 14)&lt;/p&gt; &lt;p&gt;lsid:zoobank.org:act: 7FE528FB-040A-4C14-9A73-A4695DF0E64B&lt;/p&gt; &lt;p&gt; &lt;b&gt;Specimens.&lt;/b&gt; &lt;i&gt;Holotype: BELUM. Mc 2015.638&lt;/i&gt; Rocks near San Martin Islands (65&deg;41.297&rsquo;S, 65&deg; 20.091&rsquo;W), depth 6&ndash;21 m; collected by C. Goodwin and E. Priestley, 17/02/2015.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Paratypes&lt;/i&gt;: BELUM. Mc 2015.692, BELUM.Mc2015.703 and BELUM. Mc 2015.713 Vieugue Island (65&deg;38.758&rsquo;S, 65&deg; 12.540&rsquo;W), depth 10&ndash;22 m; collected by C. Goodwin and E. Priestley, 23/02/2015; BELUM. Mc 2015.721 Port Charcot, Booth Island (65&deg;03.853&rsquo;S, 64&deg; 01.868&rsquo;W), depth 6&ndash;16 m; collected by C. Goodwin and E. Priestley, 23/02/2015. BELUM. Mc 2015.758 Paradise Bay Wall (64&deg;53.841&rsquo;S, 62&deg; 52.391&rsquo;W), depth 14&ndash;21 m; collected by C. Goodwin and E. Priestley, 24/02/2015.and BELUM. Mc 2015.775 Paradise Bay Wall (64&deg;53.841&rsquo;S, 62&deg; 52.391&rsquo;W), depth 10&ndash;24 m; collected by C. Goodwin and E. Priestley, 25/02/2015.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Comparative material examined.&lt;/b&gt; &lt;i&gt;Clathria pauper&lt;/i&gt; Brondstedt, 1927. BMNH 30.11.5.2a (tissue section and spicule preparation). Labelled &lsquo;N of Discovery Islet from type&rsquo;.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; Named after Emily Priestley who was an invaluable member of the expedition dive team.&lt;/p&gt; &lt;p&gt; &lt;b&gt;External morphology.&lt;/b&gt; &lt;i&gt;In situ appearance&lt;/i&gt; (Figure 14A): Pale yellow encrusting sponge forming patches of variable size (5&ndash;&gt; 20 cm) on bedrock. Surface covered with spiky projections up to 2 cm in length, these are sometimes branched. The projections are cored by fibres of spicules which are visible through the projection as a central core.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Preserved appearance.&lt;/i&gt; Fairly soft brown basal cushion with projecting, tapering spikes, up to 1 cm in length. Surface velvety, finely hispid.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Skeleton&lt;/b&gt; (Figure 14B): In the basal cushion the choanosomal skeleton is an irregular plumo-reticulation of thick ascending fibres of primary styles (up to 20 spicules thick) which are echinated by the acanthostyles, joined by thinner secondary tracts cored by 2&ndash;3 primary styles. In the spiky surface projections, a thick ascending fibre of principal styles (up to 20 spicules thick) cores the centre of the projection. Thinner fibres of 2&ndash;3 principal styles, heavily echinated by acanthostyles, lead up to the surface at 45&deg; angle to the central fibre. Brushes of sub-ectosomal styles join these at the surface. Microscleres are scattered throughout the tissue.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Spicules:&lt;/b&gt; Measurements from BELUM.Mc2015.638.&lt;/p&gt; &lt;p&gt;Principal styles (Figure 14C): 430(802)1105 by 14(19) 25 &micro;m. Large smooth styles which are often slightly curved.&lt;/p&gt; &lt;p&gt;Subectosomal styles (Figure 14D, E): 297(375)440 by 7(9) 11 &micro;m. Tylote head which is spined with a few large spines.&lt;/p&gt; &lt;p&gt;Acanthostyles (Figure 14F): 121(146)168 by 8(11) 21 &micro;m. Entirely spined with fairly large spines.&lt;/p&gt; &lt;p&gt;Thin toxas (Figure 14G): 154(176) 213 &micro;m.&lt;/p&gt; &lt;p&gt;Oxhorn toxas (Figure 14H): 54(69) 103 &micro;m.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Remarks.&lt;/b&gt; We have assigned this species to &lt;i&gt;Clathria&lt;/i&gt; (&lt;i&gt;Clathria&lt;/i&gt;) rather than one of the other seven subgenera on the basis of the lack of differentiation between the axial and extra-axial regions of the choanosome and the presence of a reticulate skeleton, and only a single category of auxillary styles (Hooper 2002b). Although the species has an appearance similar to &lt;i&gt;C.&lt;/i&gt; (&lt;i&gt;Axosuberites&lt;/i&gt;) &lt;i&gt;rosita&lt;/i&gt; Goodwin, Brewin &amp; Brickle, 2012 this subgenus has a distinctive extra-axial skeleton and lacks echinating megascleres (Hooper, 2002b). Of the 29 species present in the Antarctic and adjacent regions only two, &lt;i&gt;C.&lt;/i&gt; (&lt;i&gt;C.&lt;/i&gt;) &lt;i&gt;lissosclera&lt;/i&gt; Bergquist &amp; Fromont, 1988 and &lt;i&gt;C.&lt;/i&gt; (&lt;i&gt;C.&lt;/i&gt;) &lt;i&gt;pauper&lt;/i&gt; Br&oslash;ndsted, 1927, possess two distinct categories of toxa.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Clathria lissosclera&lt;/i&gt; can be distinguished as its megascleres are much smaller (choanosomal styles 170&ndash;190 &micro;m and echinating acanthostyles 85&ndash;110 &micro;m). &lt;i&gt;Clathria pauper&lt;/i&gt; was originally described as having no microscleres (hence the name). Br&oslash;ndsted (1927) describes basally spined acanthostyles up to 650 by 20 &micro;m, as well as entirely spined acanthostyles up to 250 by 12 &micro;m, and no microscleres. Hooper (1996) re-examined a fragment of the holotype (BMNH1930.11.5.2) and noted that toxas were in fact present. He gives the spicule dimensions as: principal styles with rounded smooth or microspined bases 372(606)810 by 11(15.8) 21 &micro;m; Subectosomal styles 352(481)590 by 3(7.6) 10 &micro;m; Echinating acanthostyles, subtylote with heavily spined base and lighter spined shaft 219(293)384 by 10(12.3) 15 &micro;m; smaller evenly spined acanthostyles 92(148)183 by 5(8.4) 11 &micro;m; Accolada toxas 93(139.5)185 by 0.8(0.9) 1.5 &micro;m; wing-shaped toxas 31(45.5)52 by 1.5(1.7)2.0 &micro;m). Our re-measurements of the type specimen agree with these. Our specimen differs from &lt;i&gt;C. pauper&lt;/i&gt; in only having one category of evenly spined echinating acanthostyles, larger oxhorn toxas, and much longer principal styles.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution.&lt;/b&gt; Currently only known from the type and holotype localities.&lt;/p&gt;Published as part of &lt;i&gt;Goodwin, Claire E., Berman, Jade &amp; Hendry, Katharine R., 2019, Demosponges from the sublittoral and shallow-circalittoral (&lt;24 m depth) Antarctic Peninsula with a description of four new species and notes on in situ identification characteristics, pp. 461-508 in Zootaxa 4658 (3)&lt;/i&gt; on pages 487-488, DOI: 10.11646/zootaxa.4658.3.3, &lt;a href="http://zenodo.org/record/3376028"&gt;http://zenodo.org/record/3376028&lt;/a&gt