Callyspongia (Callyspongia) scutica, Van, Rob W. M., 2017

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 23-26

Callyspongia (Callyspongia) scutica sp. nov.

Figures 13 a–c, 14a–f

Callyspongia aff. diffusa sensu Johnson 1971: 107 , fig. 9 (not: Cladochalina diffusa Ridley, 1884 )

Material examined. Holotype, RMNH Por. 9874, 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 .

Paratype RMNH Por. 9968, 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 .

Additional (non-type) specimens. RMNH Por. 6307, 9366, 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. 9332, Guyana, ‘Luymes’ Guyana Shelf Expedition, station 65, 7.55°N 57.0833°W, depth 63 m, sandy bottom, 31 August 1970 ; RMNH Por. 9396, 9865, 10502, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F45, 6.4417°N 56.5467°W, depth 34 m, Van Veen grab, 7 May 1966 ; RMNH Por. 9873, 10515, 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 ; RMNH Por. 9883, 9967, 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. 9897, 9913, 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. 9959, 9962, 9976, 9986, Suriname, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station F40, 7.0033°N 56.4417°W, depth 59 m, bottom sand, 6 May 1966 .

Examined for comparison. BMNH 1969.7.1.2, Callyspongia aff. diffusa sensu Johnson 1971 , Brazil (labeled as ‘ Cladochalina diffusa’).

Description. Erect, arborescent sponges ( Figs 13 a,a1,b), with long, sparingly dividing, often somewhat flattened, branches. There is a tendency to have the branches in one plane. Branch ending swollen, but terminally pointed. Size up to 25 cm high, 8 cm wide, individual branches 4–10 mm in diameter. Outline of the branches undulating, with flush oscules of 1–2 mm diameter arranged predominantly on the sides of the branches, on top of the undulations. Surface shiny smooth, unbroken, but with subdermal reticulation faintly visible beneath the skin. Color in alcohol golden red-brown. Consistency firm, resilient.

Skeleton. Typical of subgenus Callyspongia : at the surface a neat tangential ‘double’ fiber reticulation ( Figs 14 a,c,e), with thicker fibers of 15–30 µm thick, enclosing meshes of 250–350 µm, subdivided into triangular to polygonal meshes of 80–120 µm in diameter formed by thin fibers of 4–10 µm thick. In the choanosome there is a regular rectangular fiber skeleton ( Figs 14 b,d,f), with ascending fibers 30–125 µm in thickness, interconnecting fibers 20–40 µm in thickness, enclosing meshes of 250–750 µm in size. All fibers are cored, at the surface with 1–3 spicules, in the choanosomal ascending fibers up to 5 spicules, interconnecting fibers with 3–4 spicules.

Spicules. Oxeas only.

Oxeas ( Fig. 13 c), fusiform, sharply pointed, slightly curved, 81– 104 –114 x 3.5– 5.1 –7 µm.

Distribution and ecology. Guyana Shelf, on sandy bottoms at 25–68 m depth.

Etymology. Scutica (L.), a noun in apposition, meaning whip, lash or strap, referring to the ‘cat o’nine tails’ shape of the sponge.

Remarks. There can be little doubt that Johnson’s (1971) Callyspongia aff. diffusa is a specimen of the present new species. She described a ramose specimen with oscules on the sides of the flattened branches. Total length of the specimen was 35 cm. Skeletal details and spicule sizes as observed in the BMNH slide also match. Cladochalina diffusa Ridley, 1884 was originally described from Singapore and is a cushion-shaped sponge, unlike the present species.

There is also a distinct similarity with Callyspongia pergamentacea ( Ridley, 1881) , originally described from SE Brazil as Chalina armigera var. pergamentacea , but subsequently reported from NE Brazil by Collette & Rützler (1977) and Hajdu et al. (2011). This is a flattened smooth, semi-erect Callyspongia , which appears to be also a member of the subgenus Callyspongia . Like the ramose specimens described above, it has the oscules on elevated rows along the margin of the lamellate habitus. Oxeas are shorter and thinner than in the present specimens, and the oscules have a slight margin and are larger (3 mm or more in diameter). The new species is likely closely related to C. (C.) pergamentacea , but the long branches of the present specimens and the larger and fatter oxeas preclude their conspecificity.

Other ramose Callyspongia species reported from the Central West Atlantic are Callyspongia (Cladochalina) armigera (Duchassaing & Michelotti, 1864) , Callyspongia (Callyspongia) arcesiosa De Laubenfels, 1936 (type specimen USNM 22525 reexamined), Callyspongia (Cladochalina) tenerrima Duchassaing & Michelotti, 1864 , and Callyspongia (Callyspongia) strongylophora Hartman, 1955 . The first two are repent, non-erect, and their surface is conulose, both remaining species have thinly strongylote spicules (the spicules of C. arcesiosa are also very thin, but appear to be oxeas). All four have distinctly different habitus and skeleton.

Figures

FIGURE 13. Callyspongia (Callyspongia) scutica sp. nov., a, habitus of holotype RMNH Por. 9874 (scale bar = 1 cm), a 1, detail of branches of a (scale bar = 1 cm), b, habitus of paratype RMNH Por. 9968 (scale bar = 1 cm), c, SEM images of oxeas of holotype RMNH Por. 9874.

FIGURE 14. Callyspongia (Callyspongia) scutica sp. nov., holotype RMNH Por. 9874, a – d, SEM images of skeleton, a, overview of surface with oscule, b, cross section of branch, c, detail of ‘ double’ surface skeleton, d, cross section of peripheral skeleton, e – f, lightmicroscopic images of skeleton, e, surface skeleton showing unispicular spicule network, f, cross section of choanosomal skeleton showing rectangular reticulation of paucispicular fibers.