Leucosolenia salpinx, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 200

Leucosolenia salpinx sp. nov.

Figures 126 a–d, 127a–e

Material examined. Holotype RMNH Por. 9743, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 73, 6.7667°N 57.2667°W, depth 27.5 m, benthic sledge, muddy sandy bottom, 31 August 1970 (type material includes two light microscopic slides).

Paratype RMNH Por. 9744, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 112, 7.4°N 57.6°W, depth 39 m, triangular dredge, 5 September 1970 .

Description. ( Figs 126 a–d) Groups of tiny, individual, olynthus-type tubes attached to the tails of Tetilla pentatriaena specimens. Shape trumpet-like ( Figs 126 a–b), tapering from a wide apical aperture to a thin attachment tail. Apical aperture surrounded by a fringe of trichoxeas ( Fig. 126 d). Tube body hairy ( Fig. 126 a), with long single trichoxeas and microdiactines protruding at right or oblique angles from the body. Length of tubes 2–3 mm, width of the tubes 200–250 µm. Color in alcohol transparent-whitish.

Skeleton. ( Figs 126 c–d) Undifferentiated skeleton consisting of tangential sagittal triactines, tetractines and long thin trichoxeas, together forming the wall of the ascon-type sponge body. Long trichoxeas curve out from the skeleton and protrude far beyond the surface. Microdiactines are lodged in the skeleton between the triactines. Towards the thin tapering end, long thin trichoxeas become proportionally dominant, and at the end only trichoxeas are found in the skeleton.

Spicules. ( Figs 127 a–e) Triactines, tetractines, trichoxeas, microdiactines.

Triactines, sagittal, with straight, long, unpaired actine, divisible more or less clearly into (1) those with short, recurved, paired actines and the longest unpaired actines ( Fig. 127 a,a1), which are also slightly fusiform, unpaired actines 281– 337 –452 x 2 – 4.4 –6 µm, paired actines 36– 46 – 59 x 1.5– 3.1 –4 µm, and (2) those with variable lengths of unpaired actines ( Figs 127 b,b1,b2), which are straight and not fusiform, and possess relatively longer paired actines, which are more gradually curved, unpaired actines 51– 169 –315 x 2.5– 3.9 –5 µm, paired actines 27– 74 – 99 x 2.5– 3.4 –5 µm.

Tetractines ( Figs 127 c,c1,c2), of variable form, with straight unpaired actines much shorter than those of the triactines, apical actine usually much shorter than the basal and paired actines, usually slightly sagittal but occasionally almost equiradiate, unpaired actines 42– 154 –282 x 3 – 3.9 –6 µm, paired actines 24– 75 – 96 x 3 – 3.3 –4 µm, apical actines 14– 24 – 32 x 2 – 2.9 –4 µm.

Long trichoxeas ( Figs 127 d,d1), curved, in a large size variation, those of the main body and the fringe apparently indistinguishable, but those oblique to the surface of the wall and of the thinly tapering distal end of the body clearly longer than the others, with pointed ends frequently finely spined, 310– 468 –984 x 1.5– 1.8 –2.5 µm

Microdiactines ( Figs 127 e,e1), straight, entirely spined, 72– 151 –270 x 1.5– 2.0 –3 µm.

Distribution and ecology. Guyana Shelf, on soft bottom at 27.5–39 m depth.

Etymology. Salpinx (Gr.) , a noun in apposition, meaning trumpet, referring to the shape of the body.

Remarks. The genus assignment of this new species is not certain. At first I thought this was likely a species of Soleneiscus Borojevic, Boury-Esnault, Manuel & Vacelet, 2002a (subclass Calcinea) because of the olynthuslike habitus. Although Soleneiscus species were reported to possess exclusively tetractines as the structural spicules supporting the tube walls, recently Azevedo et al. (2015) described a Soleneiscus from Peru with triactines, S. pedicellatus Azevedo, Condór-Luján, Willenz, Hajdu, Hooker & Klautau, 2015 . The present specimens somewhat resemble S. pedicellatus , but in addition to the triactines, there are also tetractines and diactines, making the new species clearly different. One of the reviewers convinced me that the material described here fits much better in Leucolosenia (combination of sagittal tri-and tetractines and trichoxeas, presence of spined microdiactines), and accordingly I assigned the new species to that genus. The new species is distinct among the few known Central West Atlantic Leucosolenia species by the habitus of single ascon tubes, lacking any side tubes. Florida species L. horrida (Schmidt in Haeckel, 1872) is a globular cluster of anastomosed tubes spined by protruding lanceolate giant diactines, quite dissimilar to the new species.

Figures

FIGURE 126. Leucosolenia salpinx sp. nov., a – b, light microscopic images of two individual tubes together belonging to the holotype RMNH Por. 9743, c, light microscopic image of the tube wall showing tangential triactines and echinating diactines, d, apical aperture showing fringe of diactines.

FIGURE 127. Leucosolenia salpinx sp. nov., a – e, SEM images of the spicules of the holotype RMNH Por. 9743, a, sagittal triactine with very long unpaired actine of the tube walls, a 1, detail of a, b – b 1, triactines with variable unpaired actine length, c, – c 1, tetractines, c 2, detail of c, d, long diactine, d 1, faintly spined ending of d, e, short spined diactine, e 1, detail of e.