Oceanapia ascidia ( Schmidt, 1870 ) Schmidt, 1870

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 43-45

Oceanapia ascidia ( Schmidt, 1870) comb. nov.

Figures 27 a–d

Reniera ascidia Schmidt, 1870: 40 .

Rhizochalina amphirhiza Schmidt, 1880: 76 , pl. VI fig. 12.

Oceanapia robusta sensu Ridley & Dendy 1886:332 ; Muricy et al. 2011: fig. 11H (Not: Isodictya robusta Bowerbank, 1866 ).

Oceanapia fistulosa sensu Van Soest 1980: 85 , pl. XIII fig. 4, text-fig. 31; Pulitzer-Finali 1986: 159; Lehnert & Van Soest 1998: 94; Muricy et al. 2011: 109.

(Not: Desmacidon fistulosa Bowerbank, 1873 ).

Material examined. RMNH Por. 9300, 9930, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F41, 6.9133°N 56.4767°W, depth 55 m, Agassiz trawl, 6 May 1966 ; RMNH Por. 9310, Suriname, ‘ Luymes O.C.P.S. II’ Guyana Shelf Expedition, station M98, 7.1767°N 53.845°W, depth 85 m, bottom coarse sand, rectangular dredge, 16 April 1969 ; RMNH Por. 9737, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 110, 7.496°N 57.5833°W, depth 47 m, Van Veen grab, 5 September 1970 ; RMNH Por. 9769, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 68, 7.4167°N 57.1333°W, depth 51 m, muddy sand bottom, 31 August 1970 ; RMNH Por. 9836, 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. 9934, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 63, 7.5833°N 57.0667°W, depth 71 m, sandy bottom, 31 August 1970 ; RMNH Por. 9993, 10537, 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 ; RMNH Por. 10519, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 51, 7.6833°N 57.0333°W, depth 98 m, bottom calcareous sand, 30 August 1970 .

Examined for comparison. Slide BMNH 1870.5 . 3.106, labeled ‘ Reniera ascidia Schmidt Florida’ (larger oxea spicules 225 x 14 µm); photo of syntype specimen MCZ PORa 6423, labeled ‘ Reniera ascidia , Florida, 120 fms, 33’; photo of syntype MCZ PORb 214, Rhizochalina amphirhiza, Agassiz 1876 –78; slide BMNH 1887.5 . 2.244, labeled ‘ Oceanapia robusta, Challenger Exped. , Bahia or Bermuda’.

Description. ( Figs 27 a,a1) Main body rounded, about 2–6 cm in diameter (MCZ syntype 3 cm), with several (3–7) sturdy fistules (4 in the MCZ syntype), distributed over the main body at all sides, not clearly distinguished in root fistules and upper fistules. Length of the fistules 2–9 cm (3 cm in the syntype), about 0.5 cm in diameter near the main body, tapering to 2 or 3 mm at the apices. Fistules may be branched or fringed near the thin apices. Color pale brown with yellow or pink tinges.

Skeleton. Ectosomal skeleton ( Fig. 27 b) consisting of a reticulation of intercrossing single spicules. Subectosomal tracts of 40–70 µm diameter (7–11 spicules in cross section) carry the ectosomal reticulation, on the main body the tracts form polygonal meshes of widely different sizes, on the fistules these tracts are lengthwise arranged with occasional anastomoses. The interior skeleton of the main body is pulpy, with many loose spicules and irregular thick tracts running through the spicule mass.

Spicules. Oxeas only.

Oxeas ( Figs 27 c–d), slightly curved, sharply pointed, in a wide size range, divisible in two distinct size classes, (1) larger ( Fig. 27 c) 219– 255 –271 x 8.5– 12.1 –14 µm, and (2) smaller ( Fig. 27 d) 77– 104 –129 x 3 – 5.2 –7 µm.

Distribution and ecology. Guyana Shelf, Florida, Greater Caribbean, NE Brazil, on soft bottoms at 10–216 m depth.

Remarks. The identification of the present material with the ill-known Reniera ascidia Schmidt, 1870 is based on Schmidt’s description, on examination of Schmidt’s slide in the Natural History Museum, London, and on photos of the MCZ type material, kindly provided by Dr. Adam Baldinger. Schmidt’s description on p. 40, translated in English by me: ‘One of the investigated specimens is compressed sack-shaped with two extensions, of which one carries the opening of a thick tube. Another specimen, which cannot be separated from the first, is a rounded body of 1.5–2 inches (3.5–5 cm, my words) diameter and with several tubular extensions of 3–4 mm diameter. The spicules measure about 0.2 mm (200 µm, my words). Florida. 120 fathoms (216 m, my words).’ These data conform rather closely to the description above. The specimen size data given by Schmidt are slightly larger than those of the preserved syntype, as it is now about 1 inch in diameter, with several cut-off fistule bases on all sides. Because I have not yet been able to examine spicules, the synonymy with Rhizochalina amphirhiza Schmidt, 1880 (p. 76) is less certain, but the figure of the habitus drawn by Schmidt (pl. VI fig. 12) and the very similar photo of the preserved type provided kindly by Dr Adam Baldinger leave little doubt.

This species was already well known from the Caribbean region under the name Oceanapia fistulosa ( Bowerbank, 1873) . However, this name was originally given to a Western Australian species, and only subsequently used by several authors for specimens from the Atlantic because of superficial similarity ( Ridley & Dendy 1887) (Azores), Hechtel (1976) (Brazil), Van Soest (1980) (Puerto Rico), Pulitzer-Finali (1986) (Jamaica and Dominican Republic), Lehnert & Van Soest (1998) (Jamaica), Alcolado (2002) (Cuba). In view of the many records and varied descriptions given for the species in studies from the Indo-West Pacific (compare e.g. descriptions of Vacelet et al. 1976 and Desqueyroux-Faúndez 1987), it appears prudent to assign Central Western Atlantic specimens to a separate species. Thus, I propose here to assign these specimens, including the presently described, to Oceanapia ascidia , while restricting the name O. fistulosa to Indo-West Pacific specimens.

Figures

FIGURE 27. Oceanapia ascidia (Schmidt, 1870), a, habitus of RMNH Por. 9993 (scale bar = 1 cm), a 1, of RMNH Por. 9300 (scale bar = 1 cm), b, light microscopic image of the surface skeleton, c – d, SEM image of spicules, d, large oxea, d, small oxea.