Acryptolaria pseudoundulata, Peña Cantero & Vervoort, 2010

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, Zoosystema 32 (2), pp. 267-332 : 317-318

Acryptolaria pseudoundulata n. sp.

( Figs 25 ; 30 ; 32H ; Table 26)

TYPE MATERIAL. — Loyalty Islands. MUSORSTOM 6, stn DW 457, 21°00.42’S, 167°28.71’E, 353 m, 20.II.1989, several stems on coral ; 1 stem 50 mm high, holotype (MNHN-Hy.2009-0172); several incipient stems, paratype (RMNH-Coel. no. 31527).

ETYMOLOGY. — The specific name pseudoundulata refers to the close resemblance to A. undulata n. sp.; the species name is an adjective, corresponding in gender with the (feminine) name of the genus.

ECOLOGY AND DISTRIBUTION. — Acryptolaria pseudoundulata n. sp. was collected at a depth of 353 m in the Loyalty Islands area where it was found epibiotic on coral.

DESCRIPTION

Stem up to 50 mm high. Branching scarce ( Fig. 32H ) and irregular, more or less in one plane. Branches up to second order have been observed; one primary branch has three secondary branches. Branches roughly straight ( Fig. 25A ); anastomoses present.

Hydrothecae alternately arranged in approximately one plane ( Fig. 25A ), with a double bend ( Fig. 25 ) and consequently with undulating walls: strongly curved outwards where it becomes free from the axis and slightly turned upwards soon after. The adcauline wall is convex at the adnate part and slightly concave or straight at its free portion. Abcauline wall straight or slightly convex at basal third, then with a strongly marked inflection point, forming a shallow embayment followed by an unconspicuous hump, and later on slightly concave or straight. Hydrothecal diameter largest in adnate part, but markedly decreasing at base. Diameter of free part of hydrotheca slightly narrowing towards the rim. Hydrotheca adnate for about half its adcauline length (adnate/free ratio 1.1). Hydrothecal aperture circular, oblique, directed upwards, forming an angle of c. 30° with long axis of branch. Rim even, frequently with renovations.

Large nematocysts relatively very large and fusiform ( Fig. 30 ).

Coppinia not found.

REMARKS

Acryptolaria pseudoundulata n. sp. is undoubtedly allied to A. undulata n. sp.; the relationship is discussed below, when dealing with the latter. It also resembles A. novaecaledoniae n. sp. in the shape of the hydrothecae, but in that species the hydrothecae are much more strongly directed outwards, the branches are straight and the nematocysts are much smaller (17.7 × 4.7 µm).

Figures

FIG. 25.— Acryptolaria pseudoundulata n.sp.,from MUSORSTOM 6 stn DW 457:A, branch fragment showing hydrothecal arrangement; B, C, hydrothecae. Scale bar: A, 600 μm; B, C, 250 μm.

FIG. 30. — Outline drawings of the large type nematocysts of Acryptolaria species discussed in the present report. Scale bar: 30 μm.

FIG. 32. — Colony shape and branching in Acryptolaria Norman, 1875: A, A. longitheca (Allman, 1877), from MUSORSTOM 6 stn DW 407; B, A. medeae n. sp., holotype,MUSORSTOM 4 stn CP 195; C, A. niobae n. sp., holotype,BIOCAL 1 stn DW 08; D, A. norfolkensis n. sp., holotype, BIOCAL 1 stn DW 36; E, A. novaecaledoniae n. sp., holotype, MUSORSTOM 6 stn DW 422; F, A. profunda n. sp., holotype, MUSORSTOM 6 stn DW 422; G, A. pseudoangulata n. sp., holotype, MUSORSTOM 4 stn CP 217; H, A. pseudoundulata n. sp., holotype, MUSORSTOM 6 stn DW 457; I, A. pulchella (Allman, 1888), from MUSORSTOM 3 stn DR 117; J, A. pygmaea n. sp., holotype, SMIB 4 stn DW 60; K, A. tetraseriata n. sp., holotype, MUSORSTOM 3 stn DR 117; L, A. undulata n. sp., holotype, BIOCAL 1 stn DW 66. Scale bars: A, C, F-I, 10 mm; B, D, E, K, 20 mm; J, L, 5 mm