Stryphnus levis, Kelly, Michelle & Sim-Smith, Carina, 2012

Kelly, Michelle & Sim-Smith, Carina, 2012, A review of Ancorina, Stryphnus, and Ecionemia (Demospongiae, Astrophorida, Ancorinidae), with descriptions of new species from New Zealand waters, Zootaxa 3480, pp. 1-47 : 21-23

Stryphnus levis sp. nov.

( Fig. 2 B, 6E–H, 8)

Material examined. Holotype ― NIWA 54501: NIWA Stn TAN0906/3, Whananaki, East Coast of Northland, 35.500° S, 174.541° E, 64–66 m, 4 Jul 2009. Paratypes ― NIWA 57349: NIWA Stn TAN0906/235, north of the Cavalli Islands, 34.876° S, 173.916° E, 114–117 m, 18 Jul 2009; NIWA 62045: NIWA Stn KAH9615/089, North Cape, 38.460° S, 173.828° E, 122 m, 1 Oct 1989. Other material: NIWA 75571: TAN1108/250 Ranfurly Bank, northeast of East Cape, 37.319° S, 178.867° W, 110–113 m, 0 1 Jun 2011.

Type locality. North Cape.

Distribution. Northeast New Zealand, from North Cape to Whananaki.

Description. Stout rounded conical lobes, 150 mm high x 60 mm thick, arising from a massive base, about 200 mm x 160 mm ( Fig. 2 B). Ectosome is 1.5 mm thick and clearly visible in life on the cut surface, and sponge is invested with a 1.5–2 mm thick encrustation of Desmacella dendyi . Small perforations are visible through the surface encrustation housing polychaete worms and their tubes. Surface is smooth, featureless, and velvety to the touch. Texture is firm, compressible, interior tough and siliceous. Colour is bright orange in life owing to encrusting D. dendyi , colour in ethanol is beige throughout.

Skeleton. Ectosome is 1250–1500 µm deep and clearly differentiated from the underlying choanosome, which is dense and heavily pigmented by comparison. The ectosome is translucent, diaphanous, and cavernous, with large aquiferous channels, and appears to be lightly permeated with fibrillar collagen, especially towards the lower boundary. Amphisanidasters form a thin dispersed crust on the outer surface of the sponge and are only very lightly scattered below this and throughout the choanosome. Large oxeas extend well beyond the surface of the sponge, sometimes grouped in untidy bundles, and are orientated paratangentially or obliquely to the surface. The oxeas hold an encrustation of D. dendyi about 125–250 µm above the surface. Dichotriaenes are rare, and scattered with no particular orientation in the ectosome, and are very rare in the choanosome. The choanosome is dominated by oxeas in broad oblique to paratangential swathes. Oxyasters are rare and confined to the choanosome.

Spicules. Megascleres ( Fig. 6 E–F) are oxeas ( Fig. 6 E), large, stout, slightly curved, and centrally thickened, 1775 (1117–2336) x 50 (37–66) µm; dichotriaenes ( Fig. 6 F); rare, with a stout, short conical rhabdome, 341 (283– 434) μm long, with a comparatively wide cladome, 193 (166–231) μm. Protoclad 52 (41–67) μm long, deutroclad 47 (35–60) μm long (n=10).

Microscleres ( Fig. 6 G–H) are oxyasters ( Fig. 6 G), with a few long, slender rays that are faintly acanthose, 26 (19–37) µm wide; amphisanidasters ( Fig. 6 H), smooth, 12 (10–15) µm long.

Substrate, depth range, and ecology. Collected by dredge between 64– 122 m.

Etymology. Named for the unusually smooth surface of the amphisanidasters in this species; the microscleres of Stryphnus are typically acanthose ( levis = smooth in Latin).

Remarks. Stryphnus levis sp. nov. differs from S. poculum sp. nov. by morphology (the former is massive lobate, the latter is cup-shaped), the scarcity of the dichotriaenes and choanosomal oxyasters, and the possession of smooth amphisanidasters in the former. Stryphnus levis sp. nov. can be compared with S. niger from Port Jackson, South Australia (Table 3), which is also a massive lobed/lamellate sponge, but the former is beige in life and in ethanol, and the latter is deep puce-black externally and grey internally. Stryphnus levis sp. nov. forms erect cylindrical digitate lobes and has considerably shorter oxeas and dichotriaenes than S. niger . The tropical West Atlantic species S. raratriaenus ( Cárdenas et al. 2009) (Table 3) also has rare triaenes and a thin ectosome but this species is thickly encrusting with a dark brown exterior and whitish interior. There are also spicule differences between the two species; S. raratriaenus has a second, smaller size of oxea with stylote modifications, and acanthose amphisanidasters.

Figures

FIGURE 2. New species of Stryphnus from New Zealand: A. Stryphnus poculum sp. nov., holotype NIWA 62046, ex situ, scale = 5 cm; B. Stryphnus levis sp. nov., holotype NIWA 54501, preserved, scale = 5 cm; C. Stryphnus atypicus sp. nov., holotype NIWA 44225, preserved, scale = 5 cm; D. Stryphnus novaezealandiae sp. nov., paratype NIWA 52583, ex situ, scale = 5 cm; E. Stryphnus spelunca sp. nov., holotype NIWA 52582, in situ, scale = 5 cm; F. Stryphnus ariena sp. nov., paratype NIWA 62049, ex situ, scale = 5 cm ..

FIGURE 6. Megascleres and microscleres of New Zealand species of Stryphnus: Stryphnus poculum sp. nov., NIWA 62046: A. oxea, scale = 500 µm; B. dichotriaene, scale = 200 µm; C. oxyaster, scale = 10 µm; D. amphisanidaster, scale = 5 µm. Stryphnus levis sp. nov., NIWA 62045: E. oxea, scale = 500 µm; F. dichotriaene, scale = 200 µm; G. oxyaster, scale = 10 µm; H. amphisanidaster, scale = 5 µm. Stryphnus atypicus sp. nov., NIWA 44225: I. oxea, scale = 500 µm; J. dichotriaene, scale = 200 µm; K. anatriaene, scale = 50 µm; L. protriaene, scale = 50 µm; M. oxyaster, scale = 10 µm; N – O. amphisanidasters, scale = 5 µm; P. sanidaster, scale = 5 µm.