Biemna typica Bertolino, Costa & Pansini sp. nov.

urn:lsid:zoobank.org:act: 00C6E35C-E9FE-4F3D-A752-1A91D11BAC1C

Figs 11–12; Table 6

Etymology

The new species is named after its spicule complement typical of the genus.

Type material

Holotype

CHILE – Puerto Cisnes • Seno Magdalena G; 44.763254° S, 72.891581° W; depth 15 m; 5–10 Aug. 2016; Marco Bertolino leg.; on a rocky slope by scuba diving; CILE 28; MSGN 61495.

Description

HABITUS. Massive, cushion shaped sponge, rather regular, ca 2 cm long and 2 cm thick, with very hispid surface. Colour in life bright red, remaining unchanged out of the water. Sponge compressible and friable (Fig. 11A).

SKELETON. Structure typical of Biemnidae, plumose and with variable development of spongin fibres (Fig. 11B). Choanosome plumoreticulate, with spongin fibres covered by bundles of spicules (styles) and oxeote spicules that – protruding through sponge surface – make it hispid. Ectosomal skeleton composed of brushes of megascleres (Fig. 11 C–D).

SPICULES. Megascleres: Styles I smooth, straight, slightly sinuous and thin, with regular, round heads (Fig. 12A), 1275–(1450.8)–1632 μm long and 5.2–(6.5)–7.8 μm thick; styles II smooth, curved and very thin (Fig. 12B), 293.6–(340.3)–365.22 μm long and 2–(2.25)–2.5 μm thick; styles III straight, curved or doubly bent, sometimes modified to rhabdostyles (Fig. 12C), 220–(409.7)–640 μm long and 10.4–(13.76)–20.8 μm thick. Microscleres: two raphid categories; raphids I, straight or sinuous (Fig. 12D), 87.5–(115)–167.5 μm long; raphids II, short and thick, similar to raphidioid microxeas with one microspined tip (Fig. 12E), 23.4–(36.55)–42.5 μm long. C-shaped sigmas with microspined extremities clearly divided into two size categories: sigmas I, (Fig. 12F),145.5–(136.7)–152 μm long and 2.6 μm thick; sigmas II, (Fig. 12G), 12.5–(19.8)–22.5 μm long.

Habitat

Species lives on a rocky slope covered by coralline algae, at a depth between 15 and 20 m.

Remarks

The three new species, Biemna aurantiaca sp. nov., B. erecta sp. nov. and B. typica sp. nov., differ from each other primarily in their external morphology and colour (see descriptions above and Table 6). Regarding megascleres, B. aurantiaca sp. nov. has smaller styles and tylostyles than B. erecta sp. nov., while B. typica sp. nov. has only three categories of styles, with no tylostyles. Furthermore, the microscleres differ in size between the three new species which are, therefore, clearly distinguishable from each other. From the cold waters of the Southern Hemisphere, twelve species of the genus Biemna are known (Table 6). Two of these have been reported on the Chilean coast: B. chilensis Thiele, 1905 and B. lutea Bertolino, Costa & Pansini, 2019 . The new species described in the present study differ from these two species in the presence of more categories of styles and different forms of spicules. Additionally, only one category of raphids is present in B. chilensis (see Table 6). Biemna typica sp. nov. differs from all other Biemna listed in Table 6 in the presence of only one category of styles. Biemna erecta sp. nov. and B. aurantiaca sp. nov. have spicule complements similar to B. rhabderemioides Bergquist, 1961 and B. rhabdostyla Uriz, 1988, but the latter two species possess much smaller styles and subtylostyles (Table 6).

In conclusion, the three species described here ( Biemna aurantiaca sp. nov., B. erecta sp. nov and B. typica sp. nov.) differ from each other in the size and shape of the spicules, and should be considered as new species.