Ircinia felix (Duchassaing & Michelotti, 1864)

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 19-20

Ircinia felix (Duchassaing & Michelotti, 1864)

Figures 10 a–d

Restricted synonymy:

Polytherses felix Duchassaing & Michelotti, 1864: 72 , pl. XIII fig. 2.

Ircinia felix ; Wiedenmayer 1977: 60, pl. 4 fig. 3 (with additional synonyms); Van Soest 1978: 33, text-fig. 11, pl. VI fig. 4 (with further synonyms).

Ircinia strobilina ; Van Soest 1978: 40 (in part, Guyana specimen only) (Not: Lamarck, 1814)

Material examined. RMNH Por. 9333, 9838, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 65, 7.55°N 57.0833°W, depth 63 m, sandy bottom, 31 August 1970 ; RMNH Por. 9371, 9797, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 107, 7.7°N 57.5°W, depth 65 m, muddy sand bottom with shells, 5 September 1970 ; RMNH Por. 9817, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 68, 7.4167°N 57.1333°W, depth 51 m, muddy sand bottom, 31 August 1970 ; RMNH Por. 9833, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 87, 7.5667°N 57.2667°W, depth 59 m, bottom sand and shells, 2 September 1970 ; RMNH Por. 9839, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 85, 7.65°N 57.25°W, depth 69 m, bottom sand and shells, 2 September 1970 ; RMNH Por. 9848, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M97, 7.3083°N 54.1667°W, depth 130 m, bottom coarse sand, 16 April 1969 ; RMNH Por. 9904, 9953, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station G7, 7.28°N 56.7933°W, depth 64 m, bottom sand, 7 May 1966 ; RMNH Por. 9936, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 63, 7.5833°N 57.0667°W, depth 71 m, sandy bottom, 31 August 1970 ; RMNH Por. 9966, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station G56, 7.26°N 56.6667°W, depth 67–68 m, Agassiz trawl, 10 May 1966 ; RMNH Por. 9996, Guyana, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station H57, 7.595°N 56.8767°W, depth 94 m, bottom coarse sand and shells, 11 May 1966 ; RMNH Por. 10509, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F46, 6.312°N 56.57°W, depth 25–29 m, bottom sand, 7 May 1966 .

Description. Massive, cake-shaped, globular, or more expanded ( Figs 10 a–b). Size of largest individuals in the present collection up to 15 x 10 x 6 cm. Color (in alcohol) pinkish brown or purplish grey with, at least in RMNH Por. 9333, a dark purple oscule. In other specimens oscules are less distinct and vary in diameter from 2 to 8 mm. Conules are usually about 2–4 mm in height and are about 4–6 mm apart. Consistency is compressible, but firm. The sponges are harsh to the touch.

Skeleton. ( Fig. 10 c) The surface is covered by a tough mixture of filaments and sand grains, which is carried by endings of choanosomal fibers. The fiber system is irregular and may contain a considerable load of sand grains or spicule debris, but in other parts foreign material may be virtually absent. Fibers are generally less than 100 µm in diameter, lying 400–500 µm apart, and form irregular meshes of 500 µm or more in size. Filaments ( Fig. 10 d) are usually conspicuous, but may occasionally be difficult to find in transmitted light, they are 2–5 µm in diameter with terminal knobs of about 8 µm. All these features are subject to considerable variation in the collected specimens.

Distribution and ecology. Guyana Shelf, Greater Caribbean, NE Brazil, from shallow–water down to 130 m (previously down to 100 m).

Remarks. It is with some hesitation that all the Ircinia specimens collected on the Guyana Shelf are here assigned to I. felix , as growth forms are quite variable. Several specimens are undoubted members of the species, but some others are doubtful. The species is polymorphic and can be distinguished from the similarly polymorphic sympatric Ircinia strobilina (Lamarck, 1814) only on the greater coarseness of the latter. A CREOCEAN specimen from French Guyana (72 m depth) is flattened and looks to be intermediate between I. felix and I. strobilina . Van Soest (1978) assigned a specimen from the Guyana coast (ZMA Por. 03538) to Ircinia strobilina , but this is here reassigned to Ircinia felix . Although typically inhabitants of the reef, both species have been reported from deeper water.

Figures

FIGURE 10. Ircinia felix (Duchassaing & Michelotti, 1864), a, habitus of RMNH Por. 9333 (scale bar = 1 cm), b, habitus of RMNH Por. 9936 (scale bar = 1 cm), c – d, light microscopic images of skeleton of RMNH Por. 9904, c, cross section, d, filaments.