Sponges of the Guyana Shelf Author Van, Rob W. M. text Zootaxa 2017 1 1 225 journal article 37320 10.5281/zenodo.272951 e2c88f4c-3ac2-45f9-95e4-99b75561a081 1175-5326 272951 6D68A019-6F63-4AA4-A8B3-92D351F1F69B 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 . 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, b1, details of b, c, smaller oxeote spicule, c1, details of c, d, various shapes of desmas. 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 .