Four new species of Cladorhizidae (Porifera, Demospongiae, Poecilosclerida) from the Northeast Pacific Lundsten, Lonny Reiswig, Henry M. Austin, William C. Zootaxa 2014 2014-04-09 3786 2 101 123 H4WK Lundsten & Reiswig & Austin, 2014 Lundsten & Reiswig & Austin 2014 [151,448,151,177] Demospongiae Cladorhizidae Asbestopluma Animalia Poecilosclerida 4 105 Porifera species monticola sp. nov.   Figs. 2& 3  Type material.   Holotype: CASIZ 192095; MBARI 941-A1;  January 27, 2006, Davidson Seamountoff central California, USA; latitude: 35.722787, longitude: -122.722553, depth:  1280 m. The holotypewas recovered from the summit of Davidson Seamountusing the MBARI’s ROV Tiburon.    Paratype: CASIZ 194901; MBARI  V3745-  A1, Monterey Canyon, November 14, 2013; latitude: 36.72559, longitude: -122.01423, depth: 1323.28 m. The paratypewas recovered from steep rock outcrop of the Monterey Canyon. Type locality.   Holotype: Davidson Seamount, California, USA.   Paratype: Monterey Canyon, USA.   Etymology.The species name (Latin mont= mountain + - cola= dweller), mountain dweller, is descriptive of the typelocality, where dense stands of this beautiful sponge thrive.   Diagnosis.Branching Cladorhizidaewith three size classes of megasclere styles and three microsclere typesof a single size class including acanthose tylostyles, sigmas, and palmate anisochelae.    Description. Holotype: an arborescent, dichotomously-branching sponge with bottle-brush arrangement of filaments 19.37 cmtall and 13 cmwide, but was likely wider as several branches were broken off before measuring ( Fig. 2A–E). Filaments are 1–9 mmin length ( Fig. 4A). At the base, the stalk is 7 mmwide and branches all taper to approximately 1 mmwidth distally. Attached to hard substrate via conic holdfast disk, 1.3 cmin width. Sponge is white in situ and in preserved state.  Paratype:matching description above for holotype, 28 cmtall, 9 mmwide at conical base, 6 mmstalk width, and 2 mmbranch tip width, tapering distally. Spicules. Large styles 1 ( Fig. 3A, Table 1), fusiform, straight, often with pointed end rounded, in axes of branches and stem: L 751 ± 46 µm(n=53), W 25.5± 1.4 µm(n=53). Large styles 2 ( Fig. 3B), fusiform, straight or slightly curved, in filaments and their inserts in branch axes: L 687± 69 µm(n=103), W 17.5± 2.8 µm(n=66). Large styles 3 ( Fig. 3C), fusiform, thick, strongly bent, mainly in basal cone: L 462.1± 79.7 µm(n=85), W 39.97± 7.7 µm(n=67). Microacanthotylostrongyle ( Fig. 3D) thin, rough, mostly curved, occurs in basal cone and sparsely throughout branch axes: L 98.1 ± 10.7 µm(n=50), W 1.7± 0.4 µm(n=50). Sigma ( Fig. 3E) robust, contort, without profile discontinuity near ends (not clearly sigmancistroid), occurs throughout specimen: L 22.9 ± 1.5 µm(n=50). Palmate anisochelae ( Fig. 3F) foot with frontal tooth bearing two broad lateral flukes and distal medial spine extending toward spicule center, lateral wings short and never meet the frontal tooth; without spurs; occurs throughout the specimen: L 11.8 ± 0.5 µm(n=50).  Habitat and associated fauna.  Asbestopluma monticolawas first observed while conducting ROV dives at Davidson Seamount off central Californiain 2002. A single specimen was collected in 2006 while surveying Davidson Seamount once more. A dense population of  A. monticolawas observed there and they were noted as living attached to both the seafloor and, also, dead hexactinellid sponges. Since 2006, hundreds of additional observations of this species have been made. They are abundant in Monterey Canyon off northern Californiaand central Oregon, a range of ~ 1000 km. They co-occur with numerous species of sponges (  Staurocalyptussp.,  Farreasp.,  Chonelasmasp.), corals (  Anthomastus ritteriVerrill,  Paragorgia arboreaLinnaeus, Keratosissp.,  Coralliumsp.,  Clavulariasp.), crustaceans (lithodid crabs, pandalid shrimps, amphipod), echinoderms (comatulid crinoids,  Gorgonocephalussp.ophiuroids,  Hippasteriasp.asteroids), and vertebrates (  Careproctussp., egg case of Rajiformes, and  Psychrolutes phrictusStein & Bond). Small crustaceans like the pandalid shrimp were observed to be actively climbing upon and around the branches of  A. monticola. The average depth of observation was 1236 m(±211; n=428). Oxygen concentration is low (0.85 ±0.3 ml/L; n=428) and temperature averages 3.18 °C (±0.54; n=428). Small crustacean prey were observed in various states of decomposition on  A. monticola( Fig. 4A–D).   Remarks.Among the 42 known species of  Asbestopluma, eight species branch. These are compared with  A. monticolabelow.  Asbestopluma monticoladiffers from  A. formosa( Vacelet 2006), in that it lacks the characteristic embryo-containing branching enlargements, they differ in branching patterns—  A. formosahas fan shapedbranches that divide dichotomously three or four times in a single plane with long, thin, and parallel terminal branches, and  A. monticolaalso lacks microstrongyles.  Asbestopluma monticolaresembles  A. desmophora( Kelly and Vacelet, 2011), however, it lacks desmas and sigmancistras and has bent fusiform styles in its basal cone.  Asbestopluma monticoladiffers from  A. bitrichela( Lopes et al., 2011)in a lack of desmas and anchorate/ unguiforate anisochelae. This new species differs from  A. delicata( Lopes et al., 2011)in the absence of microstrongyles and palmate isochelae.  Asbestopluma monticoladiffers from  A. magnifica( Lopes et al., 2011)in being much smaller (~50% less) in total length, in having a single size class of anisochelae, and having a microtylostrongyle. When compared to  A. furcata( Lundbeck, 1905),  A. monticolahas larger megascleres and only one size class of anisochelae (  A. furcatahas two size classes of anisochelae).  Asbestopluma monticolais very similar to  A. ramosaKoltun, however,  A. ramosahas a flabelliform branching pattern, with vertical branches emanating from a single point and much thicker branches averaging 1.2 cm.  Asbestopluma ramosahas larger spicules, especially when comparing anisochelae ( Koltun, 1959; Stone et al., 2011).  Asbestopluma ramosaalso does not appear to have the robust, bent fusiform styles of  A. monticola.  Asbestopluma monticolasuperficially resembles  A. rickettsi(described below), however,  A. monticoladiffers in having only one size class of anisochelae. In situ,  A. rickettsiis more transparent and much more delicate looking than  A. monticola.A comparison of spicule data for all known  Asbestoplumaspeciesthrough 2011 is published in Lopes et al.(2011). 3314667308 2006-01-27 CASIZ, MBARI United States of America Davidson Seamount 1280 Davidson Seamount The 4 105 CASIZ 192095, MBARI 941 2 California holotype 3314667310 [199,610,359,384] MBARI 4 105 CASIZ 194901 1 paratype 3314667304 [619,702,359,384] V 4 105 V3745 1 paratype 3314667305 [710,741,359,384] V 4 105 A1 1 paratype 3314667311 [364,917,468,493] United States of America Davidson Seamount 4 105 1 California holotype 3314667312 [927,1329,468,493] United States of America Monterey Canyon 4 105 1 paratype