Acryptolaria cf. conferta (Allman, 1877)

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 : 279-280

Acryptolaria cf. conferta (Allman, 1877) ( Figs 4 ; 30 ; Table 5)

Cryptolaria conferta Allman, 1877: 17 , 19, 20, pl. 12, figs 6-10.

Acryptolaria conferta – Peña Cantero et al. 2007: 240-243 , figs 4, 15B, 17C, 19A, tab. IV.

MATERIAL EXAMINED. — New Caledonia. BIOCAL 1, stn CP 75, 22°18.650’- 22°20.429’S, 167°23.302’- 167°23.416’E, 825-860 m, 4-5.IX.1985, 3 stems up to 15 mm high (MNHN-Hy.2009-0189). Loyalty Islands. MUSORSTOM 6, stn DW 489, 20°48.37’S, 167°05.86’E, 700 m, 24.II.1989, 2 stems up to 20 mm high (RMNH-Coel.no. 31503) ; 1 branched stem, 16 mm high (RMNH-Coel. no. 35136, slide 698).

ECOLOGY AND DISTRIBUTION. — Acryptolaria conferta is with certainty known from off Cojima, Cuba, where it was found at a depth of 810 m (Allman 1877). Our material was collected at depths from 700 to 860 m at the Loyalty Islands and in New Caledonian waters.

DESCRIPTION

Polysiphonic stems up to 20 mm high. Branching frequent,up to 3rd order branches observed, irregular and in several planes; branches in a distinct zigzag pattern ( Fig. 4 ).

Hydrothecae ( Fig. 4 ) alternate and more or less in one plane, tubular, almost cylindrical in the free part, diameter gently decreasing basally at adnate part, narrowest at base. Hydrotheca smoothly curved outwards at distal half; around three-fourths of adcauline wall adnate to internode (adnate/free ratio 2.8). Adcauline wall convex, though becoming straight at basal third. Abcauline wall straight basally and concave at distal half. Hydrothecal aperture circular, directed upwards (c. 55°). Rim even, sometimes with short renovations.

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

Coppinia not found.

REMARKS

Peña Cantero et al. (2007) provide a redescription and extensive discussion of the species. Our material strongly resembles Allman’s species in the general appearance of the colony, the strong zigzag structure of the branches and the shape of the hydrothecae. Notwithstanding these similarities, it differs from the type material in having slightly smaller hydrothecae (cf. Peña Cantero et al. 2007: table IV) and slightly larger nematocysts (20.3 × 8.2 µm in the holotype). These differences, together with the absence of coppinia in our material and the large geographical distance from the type locality (northwestern Atlantic), prevent us from definitely assigning our material to Allman’s species, waiting for further confirmation of its presence in the New Caledonian area.

Although Acryptolaria conferta is the most frequently recorded species of the genus, it has no clear distinguishing features, consequently records without information about the cnidome must be considered doubtful (cf. Peña Cantero et al. 2007).

Figures

FIG. 4.— Acryptolariacf.conferta (Allman,1877),from MUSORSTOM 6 stn DW 489: A, B, branch fragments showing hydrothecal arrangement and hydrothecae. Scale bar: 250 μm.

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