Neopodospongia pagei, Sim-Smith, Carina & Kelly, Michelle, 2011

Sim-Smith, Carina & Kelly, Michelle, 2011, Two new genera in the family Podospongiidae (Demospongiae: Poecilosclerida) with eight new Western Pacific species, Zootaxa 2976, pp. 32-54 : 41-43

Neopodospongia pagei gen. nov. sp. nov.

( Fig. 1 C, 2C, 4A–H)

Material examined. Holotype ― NIWA 52580: Archway on the SE headland of Tasman Bay, Great Island, Three Kings Islands, 34.166° S, 172.146° E, 10 m, collected by Mike Page, NIWA, on SCUBA, 27 Nov 2002.

Type location. Tasman Bay, Great Island, Three Kings Islands.

Distribution. Known only from type location.

Description. Thinly encrusting sponge, around 3 mm thick, up to 5 mm thick in places, spreading in large smooth patches measuring approximately 400 x 200 mm diameter, easily detached in leathery sheets. Surface is smooth, slightly granular with projecting microscleres, with a finely porous lacy pattern, and covered with numerous regularly spaced distinctive volcano-shaped oscules up to 2 mm high. Texture is leathery and tough in life. Colour in life is burnt orange to tan in places; colour in ethanol is cream ( Fig. 1 C).

Skeleton. The ectosome is 250–500 µm thick, densely collagenous, and packed with aciculospinorhabds arranged more or less vertically within the ectosome, with the apical spire pointing outwards, extending beyond the sponge surface. The ectosome dominates the sponge as it is leathery and easily removed from the underlying substrate. The choanosome remains attached in part to the ectosome or may remain on the substrate. The choanosomal skeleton consists of thick tracts of megascleres that arise vertically from the collagenous basal layer of the sponge, radiating to form a multitude of secondary fibres which emerge below the ectosome as delicate brushes. Aciculospinorhabds are abundant throughout the choanosome ( Fig. 2 C).

Megascleres ( Fig. 4 A, Table 2)― Strongyloxeas, faintly polytylote; 389 (304–437) x 7 (6–9) μm.

Microscleres ( Fig. 4 B–H, Table 2)― Aciculospinorhabds I ( Fig. 4 B–E), asymmetrical, with clearly differentiated ends. The basal whorl is composed of four stout directly opposed spines extending obliquely away from the shaft towards the base of the spicule; these spines may be bi- or trifurcate. The median whorl consists of eight smooth spines arranged in bifurcating pairs that encircle the shaft horizontally and are slightly off centre along the shaft. The apical whorl is a ring of spines that may be smooth or acanthose, and which are divided into three acanthose pairs on each side of the spicule ( Fig. 4 H). The apex is a spire with a distal ring of small spines, from which arises a large blunt terminal spine. Protoaciculospinorhabds are sigmoidal in shape ( Fig. 4 E). The spicules are strictly aciculospinorhabds: 44 (40–47) x 26 (22–31) μm. Aciculospinorhabds II ( Fig. 4 F–H) are a smaller, more slender version of type I; 20 (13–32) x 12 (8–20) μm.

Substrate, depth range, and ecology: The sponge was collected from vertical sides of the cave wall at the end of the archway entrance from about 10 m depth. The archway was highly exposed to swells, often exceeding 4 m in size.

Etymology. Named after Michael Page, marine ecologist at NIWA, Nelson, in recognition for the contribution he has made to our knowledge of New Zealand sponge biodiversity and marine natural products chemistry, through his extensive SCUBA collections around the country, and his experimental research in the Marlborough Sounds. Mike has a passion for New Zealand ascidians.

Remarks. No species even remotely similar to Neopodospongia pagei gen. nov. sp. nov. were known from New Zealand waters prior to the discovery of this species at the Three Kings Islands. Microfossil spicules from the Late Eocene–Early Oligocene illustrated by Hinde & Holmes (1892), and Wiedenmayer (1994), can only be construed as aciculospinorhabds but there is nothing illustrated that is quite like those of the new genus. Thin encrusting N. pagei gen. nov. sp. nov. is distinguished from other species of Podospongiidae by morphology; no genera are known to have such a consistently thinly encrusting form. The species is rare and appears to be endemic to the Three Kings Islands.

Neopodospongia pagei gen. nov. sp. nov. can be compared to species in other Podospongiidae genera found in the South Pacific region, specifically to encrusting species of Sigmosceptrella , but is clearly differentiated from these by the presence of characteristic aciculospinorhabds. Sigmosceptrella fibrosa , from South Australia, has spinorhabds with irregular bifurcate to multifurcate spined apical and basal whorls, and these are frequently dumbbell-shaped. Sigmosceptrella quadrilobata Dendy, 1922 , from the Western Indian Ocean, has spinorhabds with regular apical and basal whorls. The sponge itself is dense, fibrous and collagenous as in species of Neopodospongia gen. nov., but is thick, almost massive, with well defined plumose umbelliform tracts. Diacarnus spinipoculum , also from southern Australia and Fiji is a massive barrel-shaped species with fine umbelliform secondary tracts emerging from large hollow primary fibres ( Kelly-Borges & Vacelet 1995).

Figures

FIGURE 1. New genera and species of Podospongiidae from New Zealand, Australian, and Indonesian waters: A. Podospongia virga, holotype NIWA 52692, Cape Reinga, New Zealand; B. Podospongia colini, holotype USNM 1154618, Sulawesi, Indonesia; C. Neopodospongia pagei, holotype NIWA 52580, Three Kings Islands, New Zealand; D. Neopodospongia exilis, holotype NIWA 52579, Cavalli seamounts, New Zealand; E. Neopodospongia bergquistae, holotype NIWA 62016, Poor Knights Islands, New Zealand; F. Diplopodospongia teliformis, holotype NIWA 35005, Hikurangi Channel, New Zealand; G. Diplopodospongia rara, holotype NIWA 52693, Campbell Plateau, New Zealand; H. Diplopodospongia macquariensis, holotype QM G 331915, Seamount 8, Macquarie Ridge, Australia. Scale = 10 mm for all images.

FIGURE 2. Generalised skeletal architecture of new Podospongiidae genera and species: A. Podospongia virga, with secondary tract formation evident within the globular part of the body; B. Podospongia colini, with dendritic non-divergent tracts within the globular part of the body; C. generalised skeletal architecture of Neopodospongia species; D. generalised skeletal architecture of Diplopodospongia species.

FIGURE 4. Megascleres and microscleres of Neopodospongia gen. nov. spp. nov: Neopodospongia pagei, holotype NIWA 52580, A. strongyloxea, scale = 100 µm; B. aciculospinorhabd I; C, D. immature forms of aciculospinorhabd I; E. sigmoidal protoaciculospinorhabd I; F. aciculospinorhabd II; G. immature aciculospinorhabd II, scale B – G = 20 µm; H. top down view of the apical whorl and spire of aciculospinorhabd, scale = 5 µm. Neopodospongia bergquistae, holotype NIWA 62016, I. strongyloxea, scale = 100 µm; J. aciculospinorhabd; K. immature aciculospinorhabd; L. sigmoidal protoaciculospinorhabd, scale J – L = 20 µm; M. top down view of the apical whorl and spire of aciculospinorhabd, scale = 5 µm. Neopodospongia exilis, holotype NIWA 52579, N. polytylote style with subtylostylote modification, scale = 100 µm; O. ectosomal aciculospinorhabd; P, Q. choanosomal aciculospinorhabds, scale = 20 µm; R. sigmoidal protoaciculospinorhabd, scale O – R = 20 µm.