Haliclona (Haliclona) dianae, Sim-Smith & Hickman & Kelly, 2021

Sim-Smith, Carina, Hickman, Cleveland & Kelly, Michelle, 2021, New shallow-water sponges (Porifera) from the Galápagos Islands, Zootaxa 5012 (1), pp. 1-71 : 14-19

Haliclona (Haliclona) dianae sp. nov.

( Fig. 7 ; Table 2)

Material examined. Holotype — MCCDRS9441, Punta Essex, Isabela Island , 0.999° S, 91.442° W, 9 m, 3 Jan 2004.

Type locality. Isabela Island .

Habitat and distribution. Only known from type locality. Found growing on rock; 9 m.

Description. Thinly encrusting sponge, ≤ 3 mm thick. Conspicuous, short, raised cylindrical oscules, <2 mm in diameter, are densely scattered over the surface. Aquiferous canals are visible under the semi-translucent surface membrane giving the sponge a punctate appearance. Colour in life coral pink, colour in ethanol is beige ( Fig. 7A–B ). Texture is very soft, easily torn, surface is smooth to the touch.

Skeleton. Ectosomal skeleton is a markedly regular, unispicular isotropic reticulation ( Fig. 7C ). Choanosomal skeleton is a regular reticulation consisting of ascending uni- to paucispicular primary tracts that are connected by unispicular secondary tracts. The tips of oxeas from the primary tracts protrude slightly beyond the surface of the sponge. Spongin moderately abundant around the nodes ( Fig. 7D–E ).

Spicules. Megascleres —small oxeas with sharply pointed tips; 127 (102–139) × 8 (5–10) µm (n = 30) ( Fig. 7F ).

Etymology. Named for co-author Cleveland Hickman’s daughter Diane, who inherited his love of nature and who became his most trusted critic during the preparation of the Galápagos Marine Life Series of field guides. This species name also reflects the natural beauty of this species, with the unusual ‘divine’ coral pink colouration and beautiful regular surface (Latin = ‘of Diana/Diane’).

Remarks. Haliclona (H.) dianae sp. nov. has similar sized spicules to H. (H.) clairae sp. nov. but the two species can be differentiated by gross morphology— H. (H.) dianae sp. nov. is a coral pink with short, cylindrical oscules, while H. (H.) clairae sp. nov. is a pale lilac with long, slender, tubular fistular oscules.

Two species of Haliclona (Haliclona) have been described from the tropical/subtropical eastern Pacific. The most similar species to H. (H.). dianae sp. nov. is H. sonorensis , which is thinly encrusting, dark purple and has similar sized oxeas (127 (100–145) µm) but lacks the abundant oscules of H. (H.) dianae sp. nov. Haliclona (H.) ambrosia has two size categories of oxeas, while H. (H.). dianae sp. nov. only has one ( Table 2).

The six species of Haliclona (subgenus unknown) from the eastern Pacific, as described for H. (H.) clairae sp. nov. above, all differ from this species, as outlined in Table 2.

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Subgenus Reniera Schmidt, 1862

Diagnosis. Chalinidae with a choanosomal skeleton consisting of a delicate, regular, unispicular isotropic reticulation. Ectosomal skeleton, if present, also a tangential, unispicular, isotropic, very regular and continuous reticulation. Spongin always present at the nodes of spicules, but never abundant. Oxeas frequently blunt-pointed or strongylote. Microscleres, if present, toxas and sigmas. Sponges commonly soft and fragile (from De Weerdt 2002).

Figures

FIGURE 7. Haliclona (Haliclona) dianae sp. nov. holotype, MCCDRS9441: A. In situ. B. Preserved specimen. C. Surface view of sponge showing the tangential ectosome. D. Cross section of the ectosome and choanosome. E. Higher magnification of the cross section showing the uni- to paucispicular primary tracts (black arrow) and unispicular secondary tracts (white arrow). F. Oxeas.