Penares okokewae, Sim-Smith & Kelly, 2019

Sim-Smith, Carina & Kelly, Michelle, 2019, Review of the sponge genus Penares (Demospongiae, Tetractinellida, Astrophorina) in the New Zealand EEZ, with descriptions of new species, Zootaxa 4638 (1), pp. 1-56 : 35

Penares okokewae sp. nov.

( Fig. 27–29 ; Table 9)

Material examined. Holotype — NIWA 101248 (0CDN 6810-M), Okokewa Island , Hauraki Gulf, 36.141° S, 175.307° E, 5 m, 26 Apr 1999.

Type locality. Okokewa Island , off Port Abercrombie, Great Barrier Island .

Distribution. Only known from the type locality, Hauraki Gulf, New Zealand ( Figure 29 ). Holotype was found on a rocky slope in a cave, at 5 m.

Description. Morphology is thickly encrusting, forming broad, rounded lobes ( Figure 27B ). Dimensions of the holotype are 100 mm wide × 10 mm high. Texture is compressible and is easily torn. Surface is smooth, surface ‘skin’ thin, highly wrinkled in areas when preserved, smooth in life, very slightly sandpapery to the touch. Large oscules (1–3 mm) are scattered over the surface of the sponge, often on the apices of lobes ( Figure 27 A–C). No pores are present on the small piece of the holotype that was retained. Interior is fuzzy to the touch. Colour in life is cream, interior is tan. Colour in ethanol is beige throughout.

Skeleton. Cortical skeleton is around 150 µm thick and consists of a dense layer of microxeas, on top of which is a dense layer of microrhabds. Microxeas and microrhabds are not aligned in any particular orientation.

Choanosomal skeleton contains a single layer of dichotriaenes that are aligned with their cladome at the cortex/ choanosome boundary ( Figure 27D & E ). Tight bundles of oxeas radiate out from the centre of the sponge ( Figure 27D ). The choanosome is densely packed with large oxyasters ( Figure 27E ). Microxeas are occasionally scattered throughout the choanosome.

Spicules ( Figure 28 ; Table 9). Megascleres —oxeas ( Figure 28A ) are very small and very slender; 702 (418– 909) × 13 (9–16) µm (n = 20). Dichotriaenes ( Figure 28B ) have a short rhabdome that is shorter than the cladome width; 307 (213–384) µm long × 471 (355–618) µm wide (n = 20). Deuteroclads are widely spread and curved towards the centre of each pair of deuteroclads.

Microscleres —microxeas ( Figure 28C ) curved or straight, slightly centrotylote; 62 (34–104) × 5 (3–7) µm (n = 20). Oxyasters ( Figure 28E ), moderately large with several smooth, relatively stout, conical rays; 32 (25–50) µm in diameter (n = 20). Microrhabds ( Figure 28D ), very small and straight with bluntly rounded tips, slightly centro- tylote; 15 (6–26) × 3 (2–4) µm (n = 20).

Etymology. Named after the type locality of this species, Okokewa Island, off Port Abercrombie, Great Barrier Island.

Remarks. The possession of oxyasters, microrhabds and microxeas differentiates P. okokewae sp. nov. from the majority of New Zealand Penares , with the exception of P. deformis sp. nov., P. turmericolor sp. nov. and P. aureus sp. nov. Penares deformis sp. nov. possesses strongyloxeas and has larger oxyasters than P. okokewae sp. nov.; while P. turmericolor sp. nov. and P. aureus sp. nov. have smaller oxyasters but larger microrhabds than P. okokewae sp. nov. None of the other South Pacific Penares species possess oxyasters.

Figures

FIGURE 27. Penares okokewae sp. nov., holotype NIWA 101248: A. Holotype preserved in ethanol with several large oscules visible; B. Holotype in situ; C. Close up view of the oscules; D. Thin section showing the radial arrangement of megascleres; E. Thin section showing the triaenes position just under the cortex and the dense oxyasters in the choanosome.

FIGURE 28. Penares okokewae sp. nov., holotype NIWA 101248: A. Oxea; B. Dichotriaenes; C. Microxeas; D. Microrhabds; E. Oxyasters.

FIGURE 29. Distribution of P. okokewae sp. nov. around New Zealand. The white outline shows New Zealand’s Exclusive Economic Zone.

Tables

TABLE 9. Spicule dimensions (µm) of Penares okokewae sp. nov. Dimensions are given as the mean (minimum–maximum) length × mean (minimum–maximum) width (number of spicules measured). OX = oxea; D = dichotriaene rhab- dome, DP = dichotriaene protoclad; DD = dichotriaene deutroclad; DC = dichotriaene cladome; MOX = microxea;

Specimen	Megascleres	Microscleres
NIWA 101248	OX: 702 (418–909) × 13 (9–16) (20)	MOX: 62 (34–104) × 5 (3–7) (20)
holotype	D: 307 (213–384) (20)	MR: 15 (6–26) × 3 (2–4) (20)
	DP: 97 (61–130) (20)	O: 32 (25–50) (20)
DD: 144 (86–209) (20)
DC: 471 (355–618) (20)