Hamacantha (Hamacantha) schmidtii ( Carter, 1882 )

Hajdu, Eduardo & Castello-Branco, Cristiana, 2014, Hamacantha (Hamacantha) boomerang sp. nov. from deep-sea coral mounds at Campos Basin, SW Atlantic, and redescription of H. (H.) schmidtii (Carter, 1882) (Hamacanthidae, Poecilosclerida, Demospongiae), Zootaxa 3753 (4), pp. 384-390 : 387

Hamacantha (Hamacantha) schmidtii ( Carter, 1882)

Figs. 2 A–H

Desmacella johnsoni ; Schmidt, 1870: 53 (not: Bowerbank, 1864, as Hymedesmia johnsoni )

Hymedesmia schmidtii Carter, 1882: 297 (in part, not materials from the NE Atlantic, = Hamacantha johnsoni , cf. Stephens 1921).

Material studied. BMNH 1870.5.3.28 (microscopic preparation of the type specimen containing portions of skeletal architecture and some free spicules, Fig. 2 A–B).

Redescription (adapted and expanded from Schmidt, 1870: 53). The sponge is an irregular mass, not strikingly thick. Oxeas are very irregularly arranged only in young specimens. In the larger and older specimens these lie in tracts, having 40 µm in diameter, and these carry abundant diancistras around, that are mostly erect ( Fig. 2 B). A rosette-like cluster of large diancistras was seen composed of eight spicules ( Fig. 2 C). Oxeas, 390– 416.3 –495 µm long and 9.4– 10.8 –12.8 µm thick ( Fig. 2 C). Larger diancistras ( Fig. 2 B–E), stouter, nearly straight, fimbriae and notches well marked, hooks each about 1/3 total length, 109– 118.1 –124 µm. Intermediate diancistras ( Fig. 2 E–H), slender, contorted and markedly bent in the middle, hooks over 40 % total spicule length, sharp extremities, fimbriae clearly seen on shaft but not apparent on hooks, 44–50.0–54 Μm. Smaller diancistras ( Fig. 2 E, G–H), same general shape as intermediate category, but fimbriae not obvious in any part, 26– 36.5 –41 µm.

Figures

FIGURE 2. Holotype of Hamacantha (H.) schmidtii (Carter, 1882; Desmacella johnsoni (Bowerbank, 1864) sensu Schmidt, 1870), BMNH 1870.5. 3.28. A, Schmidt’s microscopic preparation analysed in the early 1990 ’ s. B, Larger diancistras forming a loose rosette. B, Larger diancistras erect on a tract of oxeas. C, Larger diancistra. D, Aberrant larger diancistra with a smaller diancistra lying on top of its lower extremity. E, intermediate diancistras. F – G, intermediate and smaller diancistras. Scales: C – D, 100 µm.