A new species of Cladorhiza (Porifera: Cladorhizidae) from S. California (USA)

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1 Porifera Research: Biodiversity, Innovation and Sustainability A new species of Cladorhiza (Porifera: Cladorhizidae) from S. California (USA) Henry M. Reiswig (1,2*), Welton L. Lee (3) (1) Department of Biology, University of Victoria, P.O. Box 3020 Stn CSC, Victoria, British Columbia, V8W 3N5 Canada. hmreiswig@shaw.ca (2) Natural History Section, Royal British Columbia Museum, P.O. Box 9815, Stn. Prov. Govt., Victoria, British Columbia, V8W 9W2 Canada (3) 6600 Mokelumne Ave., Oakland, CA, USA. fiddlesponge@att.net Abstract: A new, very large species of Cladorhiza, collected from 1,442 m depth on the San Juan Seamount, S. California, by the ROV Tiburon, is strikingly bilateral in symmetry and feather-like in form. The specimen, 382 mm in total length, consists of a narrow stalk attached to hard substrate by a small disc, and an elongate spatulate body. The main body, triangular in section, bears a continuous fringe of about 400, 21-mm-long marginal filaments and a series of 13 fleshy lobes projecting from the midline of the frontal surface. Major biologic processes are regionally separated. Male reproduction (as spermatic cysts) is restricted to the tissues of the frontal surface of the main body, including the frontal lobes. Female reproduction, as oocyte production, embryo development and larval maturation, occurs exclusively in two abfrontal surface tissue bands in the cushions between the keel and the more fleshy main body. Prey, exclusively small crustaceans, are captured and digested only on/in marginal filaments. The elegant bilateral symmetry attained by this species attests to the continuing experimentation with development patterns within Porifera. Keywords: California, carnivorous, Cladorhiza, new species, Porifera Introduction Cladorhizid sponges are a widely recognized group of about 100 species of highly specialized small, thin, branching, often symmetrical, deep-water forms that all probably capture small crustaceans as prey. Hajdu and Vacelet (2002) assigned authority for the family Cladorhizidae to Dendy (1922) because he erected the group name Cladorhizeae, assigning only his new species, Amphilectus unguiculatus, to it; Dendy gave no diagnosis of the group. De Laubenfels (1936) provided the first summary of the distinctive morphological and habitat characters shared by members of the three genera, Cladorhiza Sars, 1872, Asbestopluma Topsent, 1901, and Chondrocladia Thomson, 1873, that consitute the modern scope of family Cladorhizidae. Since the unique cladorhizid feeding habit remained only vaguely suspected (Sars 1872), interest in the group remained fairly minor until the spectacular revelation by Vacelet and Boury-Esnault (1995) that a member of the family (later named Asbestopluma hypogea, by Vacelet and Boury-Esnault 1996), inhabiting a shallow-water (22 m) Mediterranean cave near Marseille, France, entirely lacked choanocyte chambers and fed instead by passively capturing and digesting small crustaceans. This publication stimulated general interest in this highly specialized family of carnivorous sponges and incited greater attempts to collect these largely deep-water species. New information has been especially sought to help reveal the present distribution of the feeding habit and evidence for the environmental factors which facilitated evolution of this unexpected feeding method within Porifera. In response to our wide-ranging request for new specimens to aid our compilation of the marine sponges of California (Lee et al. 2007), L. Lundsten (Monterey Bay Research Institute = MBARI) presented us in May, 2005, with a recent submersible-collected, feather-form sponge for identification. That specimen has turned out to be a new species of Cladorhiza which is unusual in both its large size and exquisite bilateral symmetry. Here we describe the taxonomic characters distinguishing this new species, its regional functional specialization, and evidence of its carnivory, the most compelling available so far for a deepwater member of the Cladorhizidae. Materials and methods One specimen of the new species was collected from the San Juan Seamount, S. California (Fig. 1) by Dave Clague using MBARI s ROV Tiburon supported by RV Western Flyer and fixed in 70% ethanol. The specimen was broken and folded during collection. Additional occurrences of the species were extracted from dive records. For histological analysis by light microscopy, tissue blocks from various body regions were desilicified in 4% hydrofluoric acid in water for 8 h, dehydrated, embedded in paraffin, and sectioned at 12 μm. Tissues were stained with eriochrome cyanin either en block before dehydration or after mounting

2 518 sections on slides. For surface tissue examination by scanning electron microscopy (SEM), tissue blocks were dehydrated, critical-point dryed (CPD) via carbon dioxide, attached to pegs with epoxy, sputter coated with gold-palladium, and viewed in an Hitachi S-3500 SEM at the University of Victoria. Marginal filaments were desilicified, stained with rose bengal, embedded in paraffin, sectioned longitudinally to expose prey cysts, deparaffinized, and handled as surface tissues above. Spicule preparations were made by digesting tissue fragments from various body regions in hot nitric acid. Cleaned spicules were isolated by either accumulating the spicules on filters, 0.22 μm pore size nitrocellulose filters for light microscopy and ion-etched 0.2 μm pore size polycarbonate membrane filters for SEM, or rinsing the spicules by settling/decantation with water, with final transfer to cover glass on SEM pegs by pipette or forceps. Spicule preparations were viewed in either the SEM noted above or a Leo 1950 VP SEM with a standard secondary electron detector (HV=20 kv and beam current = 80μA) at the California Academy of Sciences (CAS). Measurements of slide preparations were made either directly with an ocular micrometer or indirectly by a computer-digitizer coupled to light microscopes by drawing tube (camera lucida). Data are presented as mean ± st. dev. (range, number of measurements). Systematics Phylum Porifera Grant, 1836 Class Demospongiae Sollas, 1885 Order Poecilosclerida Topsent, 1928 Family Cladorhizidae Dendy, 1922 Genus Cladorhiza Sars, 1872 Cladorhiza pteron sp. nov. Figs Type material: Holotype: California Academy of Sciences, Invertebrate Zoology , coll. D. Clague, 2 May 2004, San Juan Seamount, S. California, o N, o W (within Eclusive Economic Zone of USA), 1446m, ROV Tiburon, dive T664 from RV Western Flyer (previously MBARI specimen T664-A16). Additional material: The species was reported from 17 locations over a total range of 96 km of San Juan and Rodriguez Seamounts on Tiburon dives 629 and 664 (Table 1) and photographed in situ at most sites (Figs. 2-4). Diagnosis: Vertically elongate, bilaterally symmetrical body borne on a thin stalk attached to hard substrate by basal plate; spatulate body, attached abfrontally to edge of extended stalk, bears a complete fringe of marginal filaments with upper apical growth point; without branching. Male reproductive lobes are spaced along midline of the frontal body surface. Megascleres as two size classes of styles; microscleres as anchorate/ unguiferate anisochelae and sigmancistras. Description: The holotype (Fig. 5), the only specimen collected, is 382 mm in overall length, consisting of an elongate spatulate and feather-like body, 235 mm long attached onto Fig. 1: Location of Cladorhiza pteron sp. nov., holotype collection and additional sighting of the species, San Juan Seamount, 160 km SSW of Pt. Conception, California. Fig. 2-4: In situ photos of additional Cladorhiza pteron sp. nov., on San Juan Seamount, reproduced with permission from Monterey Bay Aquarium Research Institute. Fig. 5: Cladorhiza pteron sp. nov. holotype in frontal (left) and abfrontal (right) views. The body is twisted at a midbody discontinuity caused by folding during collection. Arrows indicate the levels of insertion of frontal lobes. Fig. 6: Frontal lobe from midbody of Cladorhiza pteron sp. nov. before sectioning. The entire lobe was desilicified and sectioned - see Figs 17A and B. Fig. 7A-B: Long styles and enlargement of the two ends from Cladorhiza pteron sp. nov. (SEM). Microscleres have been retained in Fig. 7A for size comparison. Fig. 8A-B: Short style and enlargement of the rounded head from Cladorhiza pteron sp. nov. (SEM). Fig. 9A-C: Anchorate/unguiferate anisochelae and enlargement of tips from Cladorhiza pteron sp. nov. (SEM). Fig. 10: Surface of a marginal filament of Cladorhiza pteron sp. nov. with anchorate/unguiferate anisochelae anchored in surface tissues by their narrow ends with anchorate end exposed for prey capture (SEM). Fig. 11: Sigmancistra of Cladorhiza pteron sp. nov. from the frontal surface (SEM). The equality of ends is obscured by 90 o twisting of the spicule. a dense, rigid, 8.1 mm thick stalk 165 mm in length, ending in a small basal disc 22 mm in diameter. The stalk, attached to the abfrontal surface of the body, extends the length of the body providing its primary support. The body, triangular in section, with a slightly concave frontal surface, is 16.3 mm wide and 216 mm long, bearing a complete fringe of ca. 396 marginal filaments 0.69 ± 0.12 ( , n = 26) mm in thickness and 21.4 ± 5.8 ( , n = 31) mm in length. With filaments included, the main body is effectively 68.5 mm in greatest width. Ten additional filaments occurring in a single transverse series across the frontal body surface appear to be an irregularity in their distribution. Clumping of filaments in groups in the fixed holotype appears to be an artefact of tissue fusion occurring while it was captive in the ROV holding tank after capture; it is not seen in specimens photographed in situ. The number of marginal filaments in a smaller uncollected but photographed specimen with only 6 frontal lobes was ca. 192 (Fig. 4). Eleven cylindrical or flattened-palmate frontal lobes (Fig. 6), 12.0 ± 2.8 ( , n = 11) mm long by 3-5 mm wide by ca. 1 mm thick, occur in midline of the frontal body surface, spaced 17.9 ± 10 (4.1-42, n = 10) mm apart; two additional developing frontal lobes are small knobs near the upper growth end. Spicules, megascleres: Styles of two size groups. Long styles (Figs 7A-B); length 2569 ± 660 ( , n = 108) μm, width 51.1 ± 10.2 (24-73, n = 108) μm. These are the most abundant styles. They are mostly fusiform with usually the stylote end somewhat restricted as noted above, and the point, gently rounded, not sharp. In some cases smaller constrictions may occur on the opposite (oxeote) tip. In such cases both ends are usually gently rounded. Rarely the spicules ap-

3 519 pear as typically stylote. Length/width ratios are highly variable. These spicules dominate all central areas of the sponge, from the core of the stalk and the axis to the core of all of the lateral filaments. Short styles (Fig. 8A-B); length,788 ± 235 ( , n = 102) μm, width 37.7 ± 8.5 (24-55, n = 102) μm. Short styles range from stylote with rounded head and gently rounded to pointed tip, to fusiform with either one end or both constricted so as to form a somewhat narrow, almost mucronate-like handle. In the latter case it is often difficult to say if these are fusiform styles or anisoxeas. These spicules are rare in the general body structure but dominate in the base or holdfast area.

4 520 Styles intermediate in size also occurs. These, however, are so rare (only two were found in spicule preparations) that we hesitate to designate them as a distinct size class. They measured 1539 x 18 µm and 2460 x 15 µm and are distinguished by their extreme thinness as compared to all other megascleres. These were only found between the larger styles, which support the central core of the stalk. The central core is made up of extremely tightly packed styles of the largest size class. The intermediate size styles were found in areas where the core changes thickness. While we suspect that many more of these intermediate sized spicules may occur in the core, especially in curved areas, this was impossible to verify since the core spicules are so tightly bound together that efforts to separate the individual spicules only damages and breaks spicules. We suspect that these thinner spicules fill the spaces that the larger spicules naturally form when the core becomes curved and the alignment of the larger styles is disrupted by the curvature. Microscleres: two types, anchorate/unguiferate anisochelae and sigmancistras. Anchorate/unguiferate anisochelae (Figs 9A-C), length 28.4 ± 1.5 (24-33, n = 100) μm, have the shaft gently curved. The anchorate head has three prominent lanceolate alae with their sides parallel on the upper two thirds and then tapered to a sharp point. The fimbriae are prominent, with the somewhat extended upper half gently curved. The unguiferous foot has three short, claw-like and pointed

5 521 Fig. 12: Diagram of positional tissue specialization of Cladorhiza pteron sp. nov. in cross-section (above), frontal and abfrontal renderings, showing regions of male gamete production, female gamete production and feeding. Fig. 13: Part of the right female tissue band lying between the marginal filaments (above) and keel (below) of Cladorhiza pteron sp. nov.; the late embryos and larvae are visible beneath the thin transparent surface tissues. Fig. 14: Oocyte in the process of feeding from surrounding trophocytes in the female tissue band of Cladorhiza pteron sp. nov. (LM). Fig. 15: Moderately developed embryo lying within a pinacocytelined follicle in the female tissue band of Cladorhiza pteron sp. nov. (LM). Fig. 16: Mature larvae, posterior end up, in a more expanded developmental follicle in the female tissue band of Cladorhiza pteron sp. nov. (LM). Fig. 17: Stained cross-section of the frontal lobe of Fig. 6 in entirety (A, LM montage) and in magnified view of near surface tissues (B) of Cladorhiza pteron sp. nov. Sperm follicles occur in two to three layers with dark-staining basal structure more evident as maturing follicles near the lobe surface. Fig. 18: Mature sperm follicle from the frontal body surface of Cladorhiza pteron sp. nov. (LM). Fig. 19: An intact, recently captured and encysted prey copepod within a marginal filament of Cladorhiza pteron sp. nov. (SEM). Fig. 20: An encysted prey thoroughly invaded by parenchymal cells of the sponge within a marginal filament of Cladorhiza pteron sp. nov. (SEM). Fig. 21: Completely cleaned cuticular remains of a digested prey copepod within a marginal filament cyst of Cladorhiza pteron sp. nov. (SEM). Table 1: Location of Cladorhiza pteron on Rodriguez (dive 629) and San Juan (dive 664) Seamounts, S. California from ROV Tiburon dive records. Dive Latitude Longitude Depth(m) alae. These microscleres are most abundant on the marginal filaments (Fig. 10) where they occur in massive numbers between the ectosomal membrane and the central core of the filaments. They are likewise abundant throughout the sponge on all surfaces with the exception of the base and the very lowest portion of the peduncle. Sigmancistras (Fig. 11), length 36.7 ± 2.0 (32-42, n = 100) μm, are contort with both ends ending in an acerate tip (sharp spine) the axis of which swells abruptly just behind the point and bends. The spicule is widest at this point, appearing to gradually decrease in width toward the spicule center due to rotation of the flattened axis. The two ends of this spicule type are mirror images of one another. These spicules are found predominantly on peels of surface tissues on the frontal face, the surface bearing the blunt lobes. They are abundant here and may on occasion be found elsewhere, but not reliably. Skeletal organization: the sponge is attached to the substrate via an expanded base which is formed of massive numbers of short styles closely embedded in a spongin matrix to form an exceedingly strong basal mass. These generally merge with the long styles to form an equally thick and strong core to the peduncle and body axis. In all cases, spicules of all widths fill spaces where the mass increases or decreases in width. In the base and lower axis, the parenchymal tissue is thin, thus the surface is close to the mass of styles. In the lower half of the sponge, some anisochelae may occur along with a very few sigmancistras. In the upper body, near the base of filaments, the number of microscleres borne by the surface and the thicker parenchymal tissues increases. The filaments themselves are each cored by a thin cylindrical mass of long styles which arise as lateral branches from the axis core of megascleres. The filaments have a distinct, thickened surface membrane (dermis) within which can be seen multitudes of anisochelae oriented with their larger anchorate end exposed. Thickness of the parenchymal tissue mass, between the anisochela-bearing dermis and style-bearing core varies from about μm at its widest point to almost nothing near the filament tips. Functional body regionation: The major physiological processes of male reproduction, female reproduction and feeding are restricted to very specific, non-overlapping body regions in this bilaterally symmetrical species (Fig. 12). Male gamete production takes place only on the frontal surface, concentrated in the frontal lobes. Female gamete production and embryonic development takes place in two strips of abfrontal tissues. Food capture and processing takes place only on the marginal filaments. Egg and larval production: small, young, unfed oocytes before vitellogenesis, large vitellogenous, but uncleaved oocytes, early embryos, and late larvae, occur along two abfrontal tissue bands lying in the cushion between the extended stalk and the marginal filaments (Fig. 13). The distal five centimeters lack female reproductive elements. Young oocytes are ovoid, average 42 x 72 μm diameters, with large 16 x 20 μm nucleus and a single 5.9 μm diameter nucleolus (Fig. 14). Moderately developed embryos, 567 x 892 μm in diameters, are enclosed in a cell follicle (Fig. 15). Late larvae with approximately 10,000 cells are parenchymellae (Fig. 16), typical of those known in Poecilosclerida generally. They have dimensions

6 x 778 μm, and lie loosely in a thin-walled, but expanded follicle 777 x 1407 μm in total dimensions. The anterior and lateral surfaces of the larvae are multistratified, flagellated, and 67 μm thick while the posterior surface is thinner, 33 μm thick, with unflagellated, and columnar epidermis. Spicules were not present in the brooded larvae examined. Extrapolation of measured density of embryos and larvae indicate the entire holotype has a total of 482 of these stages. Sperm Production: sperm follicles occur in a nearly continuous layer just below the dermis of the entire frontal body surface excluding the 20 mm apex growth region, but are two or three layers deep on all surfaces of the frontal lobes (Figs 17A, B). The follicles are ovoid in transverse section and larger on the frontal lobes, length 201 ± 47 ( , n = 28) μm, thickness 141 ± 20 (93-219, n = 28) μm (vs. means of 110 x 83 μm under the frontal surface. All stages of sperm maturation are present; development is synchronous within follicles but asynchronous between follicles. Many, if not all follicles, have a dark-staining, structureless lens-shaped structure on the proximal side, larger and more dense in follicles in later maturation stages and in contact with the dermis (Figs 17B, 18). Extrapolation of follicle density measured at the two locations resulted in an estimate of over 36,000 sperm follicles on the entire holotype, 88% of them produced on the frontal lobes. Prey capture and digestion: Choanocyte chambers and an aquiferous canal system are absent in the holotype. Small copepod crustaceans are attached to the surfaces of only the marginal filaments, about one copepod every five or six filaments. Some of these are partly enclosed in a pocket of the surrounding surface tissues and small swellings about the size of the copepods are clearly evident on the filaments. Serially sectioned filaments contain copepods and their remains in fully enclosed cysts within the fairly spacious but dense parenchymal layer, between the dermis and the axial spicule bundle. All stages of prey digestion are encountered, from intact and apparently freshly enclosed stages (Fig. 19), stages infiltrated by massive numbers of sponge parenchymal cells (Fig. 20), and completely cleaned and empty prey cuticles ready for elimination (Fig. 21). This set of conditions and arrangement of microscleres on filament surfaces is consistent with the conclusion that the copepods are prey, snared on projecting microscleres, overgrown by parenchymal tissues and digested in prey cysts in the parenchyme, as has been well documented only for Asbestopluma hypogea by Vacelet and Boury-Esnault (1995) and Vacelet and Duport (2004). The number and size of copepods in three completely serial-sectioned, mid-body filaments amounted to a mean of 19 copepods per filament with a size range of 0.39 ± 0.34 ( ) mm in total length. This is extrapolated to provide an estimate of 7,000 copepod prey being processed in cysts in the entire holotype at time of collection. Etymology: The name, pteron, is derived from the Greek word, пτερό for feather, reflective of the body form of the new species. Discussion In recently describing a new cladorhizid, Cladorhiza corona, from the Aleutian Islands, Lehnert et al. (2005) produced a valuable table listing the known Cladorhiza species and their characters. The 28 presently known species can be effectively compared to the new form, C. pteron sp. nov., on the basis of three principal parameters: body shape, symmetry, and spicule complement Body shape can be quite variable within Cladorhiza, however it is possible to recognize a few general categories and compare these to C. pteron sp. nov. with its stalked, unbranched, pinnate and bilateral body form. The first category includes species with a branched form, these having either small branches coalescing with the stalk and/or short branchlets to more robust, highly branched forms, almost tree-like in appearance. Filaments, if present, can be either very small or large and obvious (individual branches may appear pinnate). This group includes C. abyssicola Sars, 1872, C. corticocancellata Carter, 1876, C. gelida Lundbeck, 1905, C. methanophila Vacelet and Boury-Esnault, 2002, C. oxeata Lundbeck, 1905, and C. thomsoni Topsent, They clearly differ from the unbranched C. pteron sp. nov. A second shape category includes forms without branching of the main stem: Cladorhiza arctica Burton, 1946 (clavate body), C. grimaldi Topsent, 1909, C. fristedti (Lambe, 1900), C. rectangularis Ridley and Dendy, 1886, C. schistochela Lévi, 1993, C. septemdentalis Koltun, 1970 (cylindrical body), C. ephyrula Lévi, 1964 (discoid or vase-shape body), C. segonzaci Vacelet, 2006 (rarely partly pinnate). These clearly differ from the flattened pinnate bilateral form of C. pteron sp. nov. A third common body form within the genus is stalked with some kind of terminal swelling which may have numerous extending filaments. These include Cladorhiza bathycrinoides Koltun, 1955, C. corona Lehnert et al., 2005, C. inversa Ridley and Dendy, 1886, C. longipinna Ridley and Dendy, 1886, C. minuta (Lambe, 1900), C. mirabile (Ridley and Dendy, 1886), C. moruliformis Ridley and Dendy, 1886, C. nematomorpha Lévi, 1964, and C. similis Ridley and Dendy, No terminal swelling occurs in C. pteron sp. nov. Although three species are listed in Lehnert et al. (2005) as pinnate in form, review of original figures and descriptions show these to have cylindric body forms. They are not remotely pinnate in the sense shown by C. pteron sp. nov. A few species fall outside of these general categories: C. linearis Ridley and Dendy, 1886, has a slender axis with lateral tufts of spicules, C. mani Koltun, 1964, is a short stalked form, C. depressa Kieschnick, 1896, is laterally flattened, C. flosabyssi Topsent, 1909 has a long thin stalk and flower-like tentacles, C. microchela Lévi,1964, is a small thin filament, C. tenuisigma Lundbeck, 1905, has a main trunk with rhizoids and long tentacles, and C. tridentata Ridley and Dendy, 1886, is a small hemispheric dome. None of these come close to the form seen in C. pteron sp. nov. While C. pteron sp. nov. shares its general stalked, pinnate form with a few other species, it diverges from these dramatically by its elongate, trowel-shaped body, with the continuation of the stalk forming a flattened keel along

7 523 the abfrontal surface. The frontal surface is fringed with numerous filaments and a series of lobes projecting from the midline. With this body form, which is distinctly bilateral in symmetry, C. pteron sp. nov. is to our knowledge the only known species in this genus with this set of characteristics. Virtually all other cladorhizids are either asymmetric or show radial symmetry. Cladorhiza pteron sp. nov. has a spicule complement which includes large styles, short styles-anisoxeas and sigmancistras. Within the genus Cladorhiza, the spicule complement is generally similar. Megascleres always include one or more of the following: styles-subtylostyles, tylostyles, oxeas or acanthoxeas. Acanthoxeas are rare, occurring in only one species, C. arctica, where they are accompanied by styles-strongyles. Several cladorhizids differ by having tylostyles. These include C. flosabyssi, C. fristedti, C. inversa, C. longipinna, C. mani, C. minuta and C. tridentata. In addition a host of other cladorhizids, unlike C. pteron sp. nov., have true sigmas: C. abyssicola, C. bathycrinoides, C. corticocancellata, C. depressa, C. ephyrula, C. flosabyssi, C. gelida, C. grimaldi, C. linearis, C. mani, C. moruliformis, and C. segonzaci. Sigmancistras, like those present in C. pteron sp. nov., are reported from only three other species, C. abyssicola, which is a branched cladorhizid, C. corona and C. segonzaci. C. septemdentalis is unique by virtue of its septemdentate anisochelae. Cladorhiza pteron sp. nov., which is clearly unique among all known cladorhizid species, shares several additional characteristics with the recently reported C. corona. Both are attached directly to hard substrate and have short, thick styles-anisoxeas only in the basal plate. These were suggested to be related to attachment to a solid substrate (Lehnert et al., 2005). Likewise, both species have equal-ended sigmancistras which are not common in cladorhizids. The two species, however, differ significantly in body form and symmetry. Cladorhiza corona has a stalked form with a basal plate and two sets of distal appendages, the basal one radiating in a full circle and the distal forming a quarter circle of triangularshaped structures oriented in a plane almost perpendicular to the basal appendages, the lower portion distinctly radial in symmetry, while the upper appendage is bilateral. One can envision this to be a variant or precursor to the strict bilateral symmetry of C. pteron sp. nov. Acknowledgements We thank Lonny Lundston (MBARI) for providing access to the specimen, in situ digital photos and data from dive records. Partial funding was provided by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada to HMR. Finally we extend our thanks to Dr. Bob Van Syoc who made possible the extensive use of the facilities at the California Academy of Sciences, Mr. Scott Serata who aided in the use of the Academies SEM and to former librarian Ms. Marion Taylor who was so helpful in obtaining much of the more obscure literature. References de Laubenfels MW (1936) A discussion of the sponge fauna of the Dry Tortugas in particular and the and the West Indies in general, with material for a revision of the families and orders of the Porifera. Carnagie Institution of Washington (Tortugas Laboratory, Paper No. 467) 30: Dendy A (1922) Report on the Sigmatotetraxonida collected by H.M.S. Sealark in the Indian Ocean. Reports of the Percy Sladen Trust Expedition to the Indian Ocean in 1905, vol. 7. Trans Linn Soc London, Ser. 2, 18: Hajdu E, Vacelet J (2002) Family Cladorhizidae Dendy, In: Hooper JNA, van Soest RWM (eds). Systema Porifera: a guide to the classification of sponges, vol. 1. Kluwer Academic/Plenum Publishers, New York. pp Lee WL, Elvin DW, Reiswig HM (2007) The sponges of California, a guide and key to the marine sponges of California. Monterey Bay Sanctuary Foundation, Monterey, California Lehnert H, Watling L, Stone R (2005) Cladorhiza corona sp. nov. (Porifera: Demospongiae: Cladorhizidae) from the Aleutian Islands (Alaska). J Mar Biol Assoc UK 85: Sars GO (1872) Spongiae. In: Kongelige Norske Universitat (ed), On some remarkable forms of animal life from the great depths off the Norwegian coast. I. Partly from posthumous manuscripts of the late professor Dr. Michael Sars. Brøgger & Christie, Christiania, Norway. pp Vacelet J (2006) New carnivorous sponges (Porifera, Poecilosclerida) collected from manned submersibles in the deep Pacific. Zool J Linn Soc Lond 148: Vacelet J, Boury-Esnault N (1995) Carnivorous sponges. Nature 373(6512): Vacelet J, Boury-Esnault N (1996) A new species of carnivorous sponge (Demospongiae: Cladorhizidae) from a Mediterranean cave. In: Willenz P (ed). Recent Advances in Sponge Biodiversity. Inventory and Documentation. Bulletin de l Institut royal des Sciences naturelles de Belgique. Biologie, 66(Suppl.): Vacelet J, Duport E (2004) Prey capture and digestion in the carnivorous sponge Asbestopluma hypogea (Porifera: Demospongiae). Zoomorphology 123:

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