Niphates erecta Duchassaing & Michelotti, 1864

Van, Rob W. M., 2017, Sponges of the Guyana Shelf, Zootaxa 1, pp. 1-225 : 33-35

Niphates erecta Duchassaing & Michelotti, 1864

Figures 20 a–d

Restricted synonymy:

Niphates erecta Duchassaing & Michelotti, 1864: 93 , pl. 21 fig. 3; Wiedenmayer 1977: 96, pl. 20 figs 7–8, pl. 21 figs 1–4, textfig. 119 (with additional synonyms); Van Soest 1980: 35, pl. V figs 2–4, text-fig. 12; Zea 1987: 81, figs 21, 249 (with review of of spicule data); Campos et al. 2005: 8, figs 5A–D; Muricy et al. 2011: 105 (with further Central West Atlantic records).

Niphates digitalis forma amorpha Wiedenmayer, 1977: 98 , pl. 19 fig. 4

Niphates amorpha Van Soest, 1980: 39 , pl. VI fig.3.

Material examined. RMNH Por. 9864, 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. 9877, 9887, 9895, 9902, 9905, 9912, 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. 9890, Guyana, ‘ Snellius O.C.P.S. ’ Guyana Shelf Expedition, station H58, 7.4233°N 56.9067°W, depth 66–69 m, bottom coarse sand, 11 May 1966 ; RMNH Por. 10506, 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. More than a dozen short erect branches ( Fig. 20 a,a1) with irregular outline, up to about 10 cm long, 2–4 cm in diameter. Color in alcohol red-brown. Flush or slightly raised oscules, 2–3 mm in diameter, scattered over the uneven punctate or irregularly conulose surface. Some branches have large numbers of zoanthids. Consistency firmly compressible.

Skeleton. ( Fig. 20 b) The ectosomal skeleton is an irregular three-dimensional reticulation of spongin-encased spicule tracts that form brushes fanning out over the surface, forming meshes of 200–300 µm diameter. The choanosomal reticulation is formed by thick spicule tracts, 90–120 µm in diameter (7–15 spicules in cross section) connected by thinner cross tracts, making irregular squarish meshes of 300–500 µm diameter. Many loose spicules.

Spicules. ( Figs 20 c–d) Oxeas and sigmas, the latter not found or rare in many specimens. Oxeas ( Fig. 20 c), robust, curved, length and thickness subject to considerable variation, 213– 251 –288 x 7 – 13.1 –19 µm.

Sigmas ( Fig. 20 d), if present, rather elongated, often provided with a faint central tyle, occasionally malformed, 14– 15.6 –18 µm.

Distribution and ecology. Guyana Shelf, Greater Caribbean, NE Brazil, on reefs and on soft bottoms in deeper water down to 94 m ( Guyana Shelf 25–69 m).

Remarks. This is a common species all over the Central West Atlantic, showing considerable variation in spicule sizes and shapes, no doubt because of the wide ecogeographic range of the species. The Guyana Shelf specimens stand out by their robust oxeas, which is shared by specimens from the Colombian Caribbean ( Zea 1987), but only seldom reported from other regions. Some of the records may concern encrusting specimens, usually understood as Niphates amorpha . Wiedenmayer (1977) (p. 98) erected the forma amorpha , which falls as an infrasubspecific taxon outside the ruling of the ICZN as it was proposed after 1961 (see ICZN art.15.2). When Van Soest (1980: 39) decided to elevate the forma amorpha to species rank, he unintentionally became the author of the name, despite the fact that no (holo) type was elected. The necessity to do so became mandatory only from 1999. The taxon, although first erected by Wiedenmayer (1977), thus changed authorship to Van Soest. The matter of the type material was proposed to be settled in the World Porifera Database ( Van Soest et al. 2016), as the collections of the Smithsonian Institution's retained four specimens from Wiedenmayer's work only one of which was preserved in alcohol. The specimen, USNM 30331, has the field number B834, cited as one of four specimens by Wiedenmayer (1977) (p. 99). Assuming that Van Soest’s treatment of N. amorpha included Wiedenmayer’s material, it is proposed to elect USNM 30331 as the lectotype of Niphates amorpha . However, many authors do not distinguish this as distinct from N. erecta , and I now concur with that by formally assigning N. amorpha to N. erecta as a junior synonym.

Sigmas were present in six of the ten samples collected on the Guyana Shelf, a high proportion compared to Hechtel’s (1965) (1 in 6) and Van Soest’s (1980) (5 in 22) data.

Figures

FIGURE 20. Niphates erecta Duchassaing & Michelotti, 1864, a, habitus of RMNH Por. 9895 (scale bar = 1 cm), a 1, of RMNH Por. 9877 (scale bar = 1 cm), b, light microscopic image of cross section of peripheral skeleton of RMNH Por. 9905, c – d, SEM images of spicules, c, oxeas, d, sigma.