Petromica (Chaladesma) citrina Muricy, Hajdu, Minervino

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 67-68

Petromica (Chaladesma) citrina Muricy, Hajdu, Minervino , Madeira & Peixhinho, 2001

Figures 43 a–d

Petromica citrina Muricy et al., 2001: 117 , figs 1G, 11G–H, 15.

Material examined. RMNH Por. 9369, 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. 9990, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station E66, 7.1°N 56.1783°W, depth 65 m, Agassiz trawl, 13 May 1966 .

Description. ( Fig. 43 a) From a (buried) mass rise erect conical, grooved papillae/fistules with frayed endings. Size of basal mass up to 5 x 6 cm in lateral expansion, height of papillae 2–2.5 cm. Color in alcohol yellow-white. Surface between the grooves smooth. A few small oscules are present at the base of the papillae. Consistency firm but compressible.

Skeleton. Surface skeleton a tangential crust of intercrossing oxeas. Choanosomal skeleton of confusedly arranged oxeas, with vague ascending tracts in the papillae. Loose desmas are concentrated in the basal mass.

Spicules. ( Figs 43 b–d) Oxeotes, desmas.

Oxeotes ( Figs 43 b–c), predominantly sharply pointed oxeas, stylote modifications not uncommon, in a large size range but no clear size categories, 721– 949 – 1338 x 9 – 17.6 –27 µm.

Desmas ( Figs 43 d), monocrepid, with irregularly ramose cladi and shorter or longer rhabds, overall cladome size 310– 513 –720 µm.

Distribution and ecology. Guyana Shelf, SE Brazil, 3–65 m, encrusting rocks partially buried in the sand (previously down to 25 m).

Remarks. Although this species was described from SE Brazil and apparently so far restricted to areas S of 22°S, the present specimens share the same habitus and general spiculation and thus appear conspecific, considerably extending the distribution of the species. The oxeas of our specimens have a longer upper length, but overlap in size with the type material from Brazil . A second species of Petromica (Chaladesma) in the Central West Atlantic is P. (C.) ciocalyptoides (Van Soest & Zea, 1986) (originally as Monanthus ) differs from the present specimen by having a habitus of smooth conical fistules and possessing smaller oxeas. Assuming that both species are indeed different valid species, the Brazilian species has overall more similarity with the Guyana material .

Figures

FIGURE 43. Petromica (Chaladesma) citrina Muricy, Hajdu, Minervino, Madeira & Peixinho, 2001, a, habitus of RMNH Por. 9990 (scale bar = 1 cm), b – d, SEM images of spicules, b, larger oxeote spicule, b 1, details of b, c, smaller oxeote spicule, c 1, details of c, d, various shapes of desmas.