Clathria (Microciona) stellata, 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 : 49

publication ID

https://doi.org/10.11646/zootaxa.5012.1.1

publication LSID

lsid:zoobank.org:pub:56C6852D-AAE0-4B6B-AB57-919CD62DAEC1

persistent identifier

https://treatment.plazi.org/id/D3075148-FFEB-FFCB-FF67-8FEEB513CC2B

treatment provided by

Plazi

scientific name

Clathria (Microciona) stellata
status

sp. nov.

Clathria (Microciona) stellata sp. nov.

( Fig. 23 View FIGURE 23 )

Material examined. Holotype — MCCDRS9466, Cape Berkeley , Isabela Island, 0.010° S, 91.595° W, 12 m, 29 Nov 2004. GoogleMaps

Type locality. Isabela Island .

Habitat and distribution. Only collected from type locality; 12 m, but was commonly observed on the west side of Isabela Island . Found growing on rock .

Description. Thinly encrusting sponge, 1–3 mm thick, with a surface covered in small, rounded nodes, ≤ 2 mm in diameter. A few small, inconspicuous oscules, around 1 mm in diameter, are present, from which drain inflated asterose aquiferous channels. Colour in life is mottled pale peach and white, the lot covered by an inflated translucent white membrane ( Fig. 23A–B View FIGURE 23 ). Colour in ethanol is brown ( Fig. 23E View FIGURE 23 ). Surface is smooth, texture is firm, ectosome is not detachable.

Skeleton. No defined ectosome. A confused layer of paratangential auxiliary styles occurs at the surface of the sponge ( Fig. 23C View FIGURE 23 ). Choanosome consists of erect principal subtylostyles, with their heads embedded in the base of the sponge. The rounded nodes of the sponge arise with ascending plumose tracts of echinating subtylostyles and auxiliary styles, the pointed tips protruding beyond the surface of the sponge ( Fig. 23D View FIGURE 23 ).

Spicules. Megascleres— Auxiliary style, small and slender with a lightly acanthose head; 249 (218–297) × 5 (3–7) µm (n = 20) ( Fig. 23H–I View FIGURE 23 ). Principal subtylostyle, stout and typically curved, with a smooth shaft and a rounded, acanthose head covered in small blunt spines or nodes, a large size range; 360 (163–616) × 16 (9–24) µm (n = 30) ( Fig. 23J View FIGURE 23 ). Echinating acanthostyles, small and curved with a spined shaft and acanthose head covered in small spines and rounded nodes; 101 (64–161) × 7 (5–10) µm (n = 20) ( Fig. 23G View FIGURE 23 ).

Microscleres —Palmate isochelae; 11 (9–13) µm (n = 20) ( Fig. 23F View FIGURE 23 ).

Etymology. Named for co-author Cleveland Hickman’s grand-daughter Stella. The species name also reflects the shimmering, translucent, star-shaped aquiferous canals that emanate from the oscules on the surface of this beautiful sponge (Lat. adjective agreeing with Microciona = ‘starry’).

Remarks. Clathria (Microciona) is a large subgenus containing over 100 species, of which, eight species have been recorded in the eastern Pacific. Clathria (Microciona) stellata sp. nov. can be differentiated from most of these species by the absence of toxa. Only two eastern Pacific species do not possess toxa: C. (M.) brepha ( De Laubenfels, 1930) and C. spongigartina ( De Laubenfels, 1930) , and one species contains rare toxa ( C. mytilifila Hajdu, Desqueyroux-Faúndez, Carvalho, Lôbo-Hajdu & Willenz, 2013 ). Clathria (M.) stellata sp. nov. can be differentiated from these species as follows:

C. (M.) brepha from California is a salmon red sponge that has principal acanthostyles and arcuate isochelae

(17–25 µm) ( Lee et al. 2007);

C. (M.) spongigartina from California is a brownish red sponge that has principal acanthostyles and two size categories of chelae that are 23–50 µm in length ( Lee et al. 2007);

C. (M.) mytilifila from Chile is a yellowish-beige sponge that possesses: ectosomal and choanosomal tylostyles;

acanthtylostyles I (243 (164–286) µm) that are smaller than those of C. (M.) stellata sp. nov.; and rare toxa.

A new, unnamed species of Clathria (Microciona) has been recently described from the Colombian Pacific, but this species is scarlet red in life and possesses toxa ( Lizarazo Rodríguez et al. 2020).