Aplysinopsis bergquistae, Van, Rob W. M., Kaiser, Kirstie L. & Syoc, Robert Van, 2011

Van, Rob W. M., Kaiser, Kirstie L. & Syoc, Robert Van, 2011, Sponges from Clipperton Island, East Pacific, Zootaxa 2839, pp. 1-46 : 35

Aplysinopsis bergquistae n. sp.

( Figs 16 A–F)

Holotype. CASIZ 103429, Clipperton Island Expedition 1994, shallow coral platform, under coral rocks, 0.6 m, coll. R.J. van Syoc, nr. RVS–231, 22 –04–1994 ( Figs 16 A–B).

Description. Massively encrusting sponge ( Fig. 16 A), size 14 x 5.5 x 2 cm, with conulose surface ( Fig. 16 B). Color mottled brown-purple, with irregularly distributed lighter parts. Conules low, blunt, less than 1 mm high or wide. Oscules not certainly present, as the few holes visible appear to be made by commensal organisms. Consistency toughly compressible.

Surface armour ( Fig. 16 C). There is a fairly light but uninterrupted sand cover of approx. 0.3 mm. Interior structure rather lacunose, with large canals and cavities, but some of these may be caused by thin vermetids (Mollusca) which are present in most sections.

Skeleton ( Fig. 16 D). A system of simple, densely cored primary fibers ( Fig. 16 E), with variable diameter of 45–148 µm, depending of the extent of coring and coarseness of coring material, lying at distances of 0.5–1.4 mm, and irregular secondary/tertiary fibers, uncored, faintly laminated and much thinner, 6–25 µm in diameter, forming fenestrated connections (‘secondary webs’) ( Fig. 16 F) with the primary fibers.

Soft tissue ( Fig. 16 D). Choanocyte chambers (ChCh in Fig. 16 D) variable in size, usually elliptical in shape, 24–39 µm in diameter. In the center parts numerous sperm cysts occur in various sizes and stages of development.

Etymology. Named after Dame Patricia R. Bergquist, on the occasion of her death, September 2009, to honour her invaluable contributions to the systematics of ‘keratose’ sponges.

Ecology. Under intertidal coral rocks.

Remarks. Assignment of the new species to the genus Aplysinopsis is based on Cook‘s (2007) key, an improved version of that of Cook & Bergquist (2002). The combination of a light surface armour, cored primary fibers and uncored irregular secondary fibers is only found in Aplysinopsis . However, so far this genus is only reliably represented by its Australian type species A. elegans Lendenfeld, 1888 with junior synonyms A. digitata Lendenfeld, 1888 and A. pedunculata Lendenfeld, 1888 (both described in the same work), despite six more previous assignments of species which are either referred to other existing genera ( A. massa Szymanski, 1904 , A. tuberosa Szymanski, 1904 , both assigned to Cacospongia Schmidt, 1862 , A. reticulata Hentschel, 1912 to Fascaplysinopsis Bergquist, 1980 , A. thielei Topsent, 1934 to Dactylospongia Bergquist, 1965 ), or are incertae sedis ( A. schmidti Marenzeller, 1877 and A. lobosa Burton, 1932 ). The occurrence of a second valid species of Aplysinopsis in a remote locality such as Île Clipperton is thus remarkable. If we would ignore the sand cover at the surface, the present species would key out as Luffariella Thiele, 1899 and perhaps this genus is potentially an alternative assignment. However, the skeleton of Luffariella is quite regular with primary and secondary fibers strictly rectangular and additionally there are finer tertiary fibers. Another close genus is Hyrtios Duchassaing & Michelotti, 1864 , with several species described from the SE Pacific ( Thiele 1905). However, in this genus, all fibers are cored by foreign material, and the surface is unarmoured.

Figures

FIGURE 16. Aplysinopsis bergquistae n. sp., holotype CASIZ 103429, A. habit, B. detail of surface showing a surface with ‘ goose flesh’ (low conules), scale bar = 1 cm, C. light microscopic view of surface armour of sand grains, scale bar = 100 µm, D. histological section of choanosome showing cored primary fiber, uncored (fragments of) secondary fibers and sperm cysts, ChCh = choanocyte chambers, scale bar = 100 µm, E. light microscopic view of primary fiber and irregularly anastomosed secondary fibers, scale bar = 100 µm, F. detail of fenestrated connection of primary and secondary fiber, scale bar = 50 µm.