Axinella coronata Bertolino, 2020

Bertolino, Marco, Costa, Gabriele, Bavestrello, Giorgio, Pansini, Maurizio & Daneri, Giovanni, 2020, New sponge species from Seno Magdalena, Puyuhuapi Fjord and Jacaf Canal (Chile), European Journal of Taxonomy 715, pp. 1-49 : 14-20

Axinella coronata Bertolino , Costa & Pansini sp. nov.

urn:lsid:zoobank.org:act:29550A2F-F048-40D5-B473-906EB62DC478

Figs 5–6 ; Table 5

Etymology

The new species is named after the crown of thin styles surrounding single tylostyles.

Type material

Holotype

CHILE – Puerto Cisnes • Seno Magdalena B; 44.650167° S, 72.89085° W; depth 20 m; 5–10 Aug. 2016; Marco Bertolino leg.; on a rocky cliff by scuba diving; CILE 22 ; MSGN 61494 .

Paratypes

CHILE – Puerto Cisnes • 1 specimen; Seno Magdalena E (Punta Tabla) ; 44.613885° S, 72.94149° W; depth 22 m; 5–10 Aug. 2016; Marco Bertolino leg.; on a rocky cliff by scuba diving; CILE 9; DISTAV • 1 specimen; Seno Magdalena C ; 44.631113° S, 72.929130° W; depth 25 m; 5–10 Aug. 2016; Marco Bertolino leg.; on a rocky wall by scuba diving; CILE 15; DISTAV .

Description

HABITUS. Fan shaped sponge, 2 cm high, very thin (2 mm maximum), with short basal stem. Surface very hispid with tufts of macroscleres coming out from surface ( Fig. 5 A–B). Consistency hard but friable. Colour in life bright yellow ( Fig. 5 A–B).

SKELETON. Plumose, formed by multi-spicular primary tracts, radiating from axis towards surface ( Fig. 5 C–D), ending in single tylostyle surrounded by crown of thin styles that projects slightly through sponge surface ( Fig. 5 E–F).

SPICULES. Megascleres: Tylostyles slightly curved ( Fig. 6A ), 1300–(1962)–2200 μm long and 10– (17.42)–25 μm thick. Long, smooth and thin styles, with shaft slightly thickened in distal third ( Fig. 6B ), 1200–(1500)–1800 μm long and 2.5–(3.3)–5 μm thick. Styles to tylostyles or subtylostyles more or less bent near head as true rhabdostyles ( Fig. 6C ), 460–(505)–590 μm long and 10–(15.62)–20 μm thick. Thin and sinuous styles, with round heads and slightly rounded points ( Fig. 6D ), 460–(556.5)–600 μm long and 2.5–(3.5)–5 μm thick.

Habitat

Recorded on rocky cliffs and walls covered by coralline algae, at a depth between 20 and 25 m.

Remarks

The attribution of A. cylindrica sp. nov. and A. coronata sp. nov. to the genus Axinella Schmidt, 1862 is based on the skeleton architecture characterised by a choanosomal skeleton differentiated in the axial (compressed or vaguely reticulated) and extra-axial (plumoreticulated) regions. The only species of this genus present on the Chilean coast is A. crinita Thiele, 1905 . This species differs from the two newly described species in external shape (very ramified with cylindrical branches ( Desqueyroux 1972)), absence of rhabdostyles (present in A. cylindrica sp. nov.) and presence of long thin styles with curved head (absent in A. coronata sp. nov.). In Table 5, the other geographically close species of Axinella and other species recorded in the Southern Hemisphere are reported. All of these species differ from A. cylindrica sp. nov. and A. coronata sp. nov. in the external morphology, and the type and size of spicules. Moreover A. cylindrica sp. nov. differs from all the other species in the presence of rhabdostyles ( Table 5).

Figures

Fig. 5. Axinella coronata Bertolino, Costa & Pansini sp. nov., holotype (CILE 22; MSGN 61494). A–B. The holotype in life. C. Plumose multispicular skeleton. D. Cross section of the skeleton. E. Ectosome. F. Magnification of a single tylostyle, surrounded by a crown of thin styles.

Fig. 6. Spicules of Axinella coronata Bertolino, Costa & Pansini sp. nov., holotype (CILE 22; MSGN 61494). A. Tylostyles. B. Styles. C. Styles bend near the head similar to rhabdostyles. D. Thin and sinuous styles.