Auletta krautteri, Austin, William C., Ott, Bruce S., Reiswig, Henry M., Romagosa, Paula & McDaniel, Neil G., 2013

Austin, William C., Ott, Bruce S., Reiswig, Henry M., Romagosa, Paula & McDaniel, Neil G., 2013, Two new species in the family Axinellidae (Porifera, Demospongiae) from British Columbia and adjacent waters, ZooKeys 338, pp. 11-28 : 13-17

Auletta krautteri sp. n. Fig. 1

Etymology.

Named after Dr. Manfred Krautter who organized a dive program in the submersible DELTA on sponge bioherms and collected the holotype.

Material examined.

Holotype: RBCM 013-00114-001; KML1105 KML Sta. 71/99 Hecate Strait, BC, (52°26.4'N, 129°40.0'W), 215 m depth, July 18, 1999, coll. M. Krautter, 1 specimen. Paratype: CMNI 2013-0001, KML1106, west of Dixon Entrance, BC, (54°370'N, 133°55.0'W), 229 m depth, 1 specimen.

Other material.

KML1106, PBS 65-77, west of Dixon Entrance, BC, (54° 37 0'N, 133°55.0'W), 229 m depth, 21 specimens; KML1108, PBS JWS-132, Queen Charlotte Sound, BC, (51°22.5'N, 129°13.5'W), Feb. 3, 1965, 16 specimens; KML1107, KML Sta. 171/76, West of Flamingo Inlet, BC, (52°09.8'N, 131°23.8'W), 200 m depth, Aug. 31, 1976, coll. W.C. Austin, 3 specimens; KML1109, PBS 71-47, off Dixon Entrance, BC, (54°30.2'N, 135°53.3'W), 256 m depth, 3 specimens; KML1105, KML Sta. 71/99, Hecate Strait, BC, (51°21.5'N, 129°13.5'W), 183 m depth; CASIZ 020231, NODC 366501, Gulf of Alaska, (59°2.0'N, 141°3.6'W), 348 m depth, 2 specimens; KML1108, PBS 981-60, Dixon Entrance, BC, (54°N, 132°W), 128 m depth; CMN 1900-86, Forester I., Alaska, (54°48'N, 133°36'W), depth no data, coll. W. Van Vliet; CMN 1900-89, sta. LM 43, Tasu, Queen Charlotte Islands, BC, (52°45'N, 132°06'W), depth no data, coll. L. Marhue; CMN 1900 sta. JWS-93, Forester I., Alaska, (54°48'N, 133°36'W), depth no data, coll. J.W. Scogoen; CMN 1900-91, W. of Queen Charlotte Islands, BC, (53°N, 132°W), depth no data, coll. W. Van Vliet; CMN 1900-93, sta. FRB 66 221 m depth, Forester I, Alaska, (54°48'N, 133°36'W), depth no data; CMN 1900-94, sta. LM-43, Tasu, Queen Charlotte I., BC, (52°45'N, 132°06'W), depth no data, coll. L. Marhue; CMN 1900-96, sta. FRB 66-2-6, off Sitka, Alaska, (57°02.3'N, 135°20.3'W), depth no data, coll. W. Van Vliet.

Description.

Macroscopic features. Erect, stalked tubes typically single (Fig. 1A), occasionally branched (2 to 3 tubes on a common base); branched forms uncommon. Overall height 5-13 cm, width of tubes 0.7-2 cm. Stalk comprises up to one third of overall height. A single 2-8 mm diameter osculum at the tube apex leads into an atrial cavity extending the length of the tube and into the stalk where the tube diameter is restricted. Wall thickness of the tube 5-10 mm. Surface felt-like to touch. Smooth inner wall penetrated by a series of elongate openings. Consistency compressible but firm and tough. Colour in life reddish-brown; grey or cream in alcohol. Specimens collected in 1965 contained oocytes 130 to 150 µm diameter.

Microscopic features. Skeletal architecture simple, composed of one to three multi-spicule tracts oriented parallel to and lining the atrial cavity, which is relatively smooth as a result (Fig. 1B). Single, or multispicular tracts branch from this longitudinal tract approximately at right angles and project to the outer surface. The branches also form short brushes, and where each branch penetrates the surface, the terminal brush forms a tuft to produce a hispid appearance (Fig. 1C).

Each tract varies from 150-400 µm in diameter. Ascending tracts are composed primarily of straight and curved styles, and secondarily of sinuous oxeas, curved oxeas and occasional sinuous strongyles (Fig. 1O, P). Straight styles or styles curved near the base form the exterior tips of ascending fibres and curved, bent or sinuous oxeas and styles form cross tract links.

The multi-spicule tracts of the atrial cavity are 500-700 µm diameter and composed of bundles of 10 to 15 spicules cemented by spongin Ascending tracts composed of fewer, typically 5 or 6, spicules in a bundle cemented by spongin. Atrial tracts composed primarily of sinuous oxeas, secondarily of curved and straight styles; occasionally sinuous strongyles, sinuous styles, and curved oxeas located in axial tracts.

Ectosome surface forms a reticulation in the areas with pores where it is elevated about 2 mm above the general surface. Easily detachable aspicular membranes are present on dermal surface stretched between spicule tracts, and on atrial surface below the longitudinal spicule tracts (Fig. 1B, C). The choanosome occupies the space between the detachable membranes and is distinguished by radial orientation of the spicule tracts, and by the somewhat different proportion of spicules, which is quite variable among different specimens.

Oscula may be ringed by long, straight styles singly or in tufts. Fringe may be absent, but if present, extends 100-300 µm beyond the osculum.

Stalk is denser than the tube, not hollow except near the tube base, and packed with branching and anastomosing multi-spicule tracts, forming a dense reticulation of two to ten or more spicules to a bundle cemented by spongin. Stalk tracts 100-400 µm diameter. Primary spicules sinuous strongyles which serve to reinforce the stem. The proportion of other stalk spicules is quite variable with sinuous oxeas, bent and curved and straight styles being variably the next most abundant. Sinuous styles and curved or bent oxeas are uncommon.

Spicules. Spicule types include straight (Fig. 1F) and bent (Fig. 1H) styles of the multi-spicule tracts; long, straight styles of the oscular fringe (Fig. 1E) and proximate area; sinuous (Fig. 1K, L), curved or bent (Fig. 1M) oxeas, and sinuous strongyles (Fig. 1O, P). Occasionally sinuous oxeas occur that are rounded on one end forming sinuous styles. These latter were enumerated separately to give a qualitative idea of their abundance.

Longer styles often have a reduced diameter at the head comparable to mycalostyles. Oxeas are often anisometric. Both oxeas and styles occasionally have mucronate or rounded apices. Oxeas and strongyles may occasionally be centrotylote.

Five specimens were examined in detail (Table 1).

Remarks.

Evident from the Table 1 above is the relatively large variability in disposition and size of spicules from specimen to specimen.

Our specimens fit the diagnosis for Auletta by Alvarez and Hooper (2002) except that the sinuous diacts are primarily oxeas in the tube and strongyles in the stem. Several species of Auletta are reportedtohave sinuous oxeas but no strongyles (e.g., Auletta aurantiaca Dendy, 1889, Auletta consimilis Thiele, 1898, Auletta pedunculata Topsent, 1896, Auletta lyrata (Esper, 1794)).

The following species are not conspecific with Auletta krautteri based on the absence of one or more spicule types.

Auletta andamensis Pattanayak, 2006, p. 66 No strongyles

Auletta aurantiaca Dendy, 1889, p. 92No strongyles

Auletta consimilis Thiele, 1898, p. 55 No strongyles

Auletta dendrophora Wilson, 1904, p. 158 No oxeas

Auletta grantioides Lévi & Vacelet, 1958, p. 243 No oxeas

Auletta halicondroides Thiele, 1898, p. 55 No strongyles

Auletta lyrata (Esper, 1794) No strongyles

Auletta lyrata var. brevispiculata Dendy, 1922 No strongyles

Auletta pedunculata Topsent, 1896 No strongyles

Auletta sessilis Topsent, 1904 No oxeas

Auletta sycinularia Schmidt, 1870 No oxeas

Auletta tubulosa (Ridley & Dendy, 1886), p. 482 No oxeas or strongyles

Auletta tuberosa Alvarez, Van Soest & Rützler, 1998, forms clusters of tubes which are tuberculate rather than smooth as in Auletta krautteri . It does have oxeas, but they are smaller (340 –430– 530) than in Auletta krautteri . Auletta elongata Dendy, 1905: external form consists of multiple tubes branching off a single stem rather than single tubes on each stem as in Auletta krautteri . The axial skeleton consists of stout fibres with short perpendicular anastomosing branches rather than single to three longitudinal axial fibres with relatively long arching perpendicular fibres that branch but do not anastomose. Auletta elongata var. fruticosa Dendy, 1916, is similar to Auletta elongata except it has smaller spicules.

Two other sponges originally assigned to Auletta have been reassigned to other genera: Auletta elegans Vosmaer, 1882, is now accepted as Semisuberites cribrosa (Miklucho-Maclay, 1870) ( van Soest et al. 2005): Barents Sea. Auletta celebensis Thiele, 1899 is now accepted as Stylissa massa (Carter, 1887) (Van Soest et al., op. cit.): West Pacific.

Stone et al. (2011) briefly described and showed images of a tubular form they identified as Axinella rugosa (Bowerbank, 1866) that might be con-specific with Auletta krautteri . However, Axinella rugosa in the N. Atlantic is described as bushy with irregular branches ( van Soest 2013). Lambe (1895) identified four specimens from Chika Island and Unalaska Island as belonging to Axinella rugosa . However, Cuenot (1913) argued that these were not Axinella rugosa and proposed a new name Phakellia lambei Topsent, 1913. Lambe (1895) described his specimens as dividing close to the base into two branches which subdivide above into two lobate expansions.

Conclusions.

No described species have a suite of characters matching those of our specimens. We therefore propose that the Auletta in British Columbia and Alaska be considered a new species, Auletta krautteri . We suggest that the tubular forms recorded by Stone et al. (2011) are likely Auletta krautteri .

Bathymetric range.

180 to 320 meters depth; 87 to 712 meters depth if include Axinella rugosa of Stone et al. (2011).

Zoogeographic range.

Gulf of Alaska and south to the southern end of the Queen Charlotte Islands, BC, also central Aleutian Islands if include Axinella rugosa of Stone et al. (2011).

Ecology.

The sponge is a moderately common dredged species found on rock, gravel or mud substrates. Some individuals have been found with a small red copepod (unidentified) burrowed into the surface. Two individuals examined contained a species of the isopod Gnathia , oriented head down. Unidentified gammarid amphipods and unidentified spionid polychaetes have also been observed. Numbers of the crinoid Florometra serratissima (A.H. Clark, 1907) were observed clinging to specimens of Auletta krautteri in Hecate Strait, BC.