Acryptolaria medeae Peña Cantero & Vervoort 2010, n. sp.
Creators: name: Peña Cantero, Álvaro L.
name: Vervoort, Willem
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Cnidaria
Hydrozoa
Leptothecata
Lafoeidae
Acryptolaria
Acryptolaria medeae

description: Acryptolaria medeae n. sp.
(Figs 16; 30; 32B; Table 17)
TYPE MATERIAL. — NW New Caledonia. MUSORSTOM 4, stn CP 195, 18°54.8’S, 163°22.2’E, 465 m, 19.IX.1985, 1 stem 70 mm high, with coppinia, holotype (MNHN- Hy.2009-0166); 1 stem c. 23 mm high, paratype (RMNH- Coel. no. 31518).
OTHER MATERIAL EXAMINED. — Stn DW 197, 18°51.3’S, 163°21.0’E, 560 m, 20.IX.1985, 2 stems up to 80 mm high (MNCN 2.03/424).
ETYMOLOGY. — The specific name medeae is a dedication to Medea Peña Sancho, daughter of the first author; “medeae” is a noun in genitive singular.
ECOLOGY AND DISTRIBUTION. — Acryptolaria medeae n. sp. was collected at depths between 465 and 560 m off NW New Caledonia.
DESCRIPTION
Palm-shaped stems up to 80 mm high (Fig. 32B), with the appearance of gorgonids and a disc-shaped hydrorhiza for attachment to hard substratum. Branching extremely abundant (up to sixth-order branches observed) and irregular, but strictly in one plane. Stem deprived of branches for the first few millimetres and then with continuous branching with numerous anastomoses, giving stems the aspect of a mesh. Branches slightly sinuous (Fig. 16A).
Hydrothecae alternately arranged in approximately one plane (Fig. 16A, B), almost cylindrical, but imperceptibly widening basally (Fig. 16A, B); later diameter sharply decreasing at hydrothecal base. Hydrotheca gently curved outwards; adcauline wall adnate to internode for over two-thirds of its length (adnate/free ratio 2.6), convex. Abcauline wall straight or convex at basal half, concave at distal half, with a strong development of the perisarc which is strongly reduced just over hydrotheca underneath (Fig. 16A, B). Hydrothecal aperture circular, oblique and directed upwards, forming an angle of c. 40° with long axis of branches. Rim even, sometimes with short renovations (up to 13 observed).
Large nematocysts relatively large and ovoid (Fig. 30).
Coppinia fusiform, 22 mm long and 3 mm in diameter, consisting of closely set (Fig. 16C), flaskshaped gonothecae provided with a long distal neck ending in a circular aperture with even rim (Fig. 16C, D). Gonothecal walls coalesced with strong development of the perisarc (Fig. 16D); defensive tubes absent.
REMARKS
Acryptolaria medeae n. sp. is characterized by the gorgonian-like appearance of the stems, much branched in one plane and with many anastomoses which give them a compact aspect, the strong development of perisarc at the abcauline wall of the hydrotheca, and the fairly wide gonothecae. The large nematocysts are abundant.
This new species is close to A. disordinata n. sp. in stem structure, being much branched in one plane, and by the presence of a strong perisarc development in the abcauline hydrothecal wall. Nevertheless they distinctly differ in the nematocysts which in A. disordinata n. sp. are larger (25.6 × 9.4 µm). Furthermore in the latter the branches strongly widen where the hydrothecae become free, the strong development of perisarc of the abcauline wall reaches the hydrotheca situated below, the cylindrical hydrothecae are larger and, finally, the gonothecae are in a chaotic disposition in the coppinia.
description: Published as part of Peña Cantero, Álvaro L. & Vervoort, Willem, 2010, Species of Acryptolaria Norman, 1875 (Cnidaria, Hydrozoa, Lafoeidae) collected in the Western Pacific by various French expeditions, with the description of nineteen new species, pp. 267-332 in Zoosystema 32 (2) on pages 299-300, DOI: 10.5252/z2010n2a5, http://zenodo.org/record/4521008