Acryptolaria bathyalis, 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 : 274-275

Acryptolaria bathyalis n. sp.

( Figs 2 ; 30 ; 31B ; Table 3)

TYPE MATERIAL. — Loyalty Islands. MUSORSTOM 6, stn CP 419, 20°41.65’S, 167°03.70’E, 283 m, 16.II.1989, 1 stem c. 70 mm high, holotype (MNHN-Hy.2009-

0158); several fragments up to 25 mm long, paratype (RMNH-Coel. no. 31499) and 2 slides, paratypes (MNHN-Hy.2009-0147 and RMNH Coel. no. 35167 slide 734) .

OTHER MATERIAL EXAMINED. — Loyalty Islands. BIOCAL 1, stn DW 82, 20°30.658’- 20°30.888’S, 167°50.308’- 167°50.367’E, 440-460 m, 6.IX.1985, 3 stems up to 36 mm high ( MNCN 2.03 /407) ; 1 stem c. 26 mm high in slide ( MNCN 2.03 /392) .

MUSORSTOM 6, stn CP 415, 20°40.20’S, 167°03.95’E, 461 m, 15.II.1989, 1 stem c. 45 mm high (RMNH-Coel. no. 31498) and 1 stem c. 35 mm high (RMNH-Coel. no 35113, slide 675). — Stn CP 464, 21°02.30’S, 167°31.60’E, 430 m, 21.II.1989, 1 stem c. 22 mm high (MNCN 2.03/408).

SE New Caledonia. MUSORSTOM 4, stn CP 237, 22°12.0’S, 167°16.5’E, 630 m, 2.X.1985, a few stems up to 22 mm high, on axis of gorgonian ( MNCN 2.03/409).

ETYMOLOGY. — The specific name bathyalis , from the Greek “bathos” = deep, refers to the depths at which the species was found; it is an adjective following the genus name in gender.

ECOLOGY AND DISTRIBUTION. — Acryptolaria bathyalis n. sp. was found at depths between 283 and 630 m; one colony was attached to the axis of a gorgonian. It has been collected at the Loyalty Islands and SE of New Caledonia.

DESCRIPTION

Stems up to 70 mm high. Branching frequent, at least 5th order branches present ( Fig. 31B ). Branching irregular in several planes, occasionally in one plane; with anastomoses. Branches straight, long and thin; with exception of basal part of stem, perisarc of branches little developed ( Fig. 2A, C, E ).

Hydrothecae alternately arranged in approximately one plane ( Fig. 2A, C, E ), cylindrical ( Fig. 2 ), with a constant diameter throughout, only decreasing at their base. Hydrotheca curved outwards at distal half; basal half of abcauline hydrothecal wall parallel to branch. Adcauline wall adnate to internode in about four-fifths (adnate/free ratio 3.8). Adcauline wall convex throughout; abcauline wall completely concave or straight at basal half.Hydrothecal aperture circular and outwards directed, roughly parallel to long axis of branches. Rim even, sometimes with short renovations.

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

Coppinia not found.

REMARKS

Acryptolaria bathyalis n. sp. is characterized by the cylindrical hydrothecae and the soft, long and straight branches. It is allied to Acryptolaria abies in having straight branches and in the shape and size of the hydrothecae, though the latter has a larger part of the adcauline wall free. They are clearly distinguishable by the size of the nematocysts (11.2 × 4.6 µm in the lectotype of A. abies ).

Figures

FIG. 2. — Acryptolaria bathyalis n. sp.: A, C, E, branch fragments showing hydrothecal arrangement;B, D, F, hydrothecae;A, B, from MUSORSTOM 6 stn CP 419; C, D, from MUSORSTOM 6 stn CP 415; E, F, from BIOCAL 1 stn DW 82. Scale bar: A, C, E, 600 μm; B, D, F, 250 μm.

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

FIG. 31. — Colony shape and branching in Acryptolaria Norman, 1875: A, A. angulata (Bale, 1914), from MUSORSTOM 6 stn DW 487;B, A. bathyalis n. sp., holotype, MUSORSTOM 6 stn CP 419; C, A. bulbosa (Stechow, 1932), from MUSORSTOM 6 stn CP 419; D, A.disordinata n.sp.,holotype,MUSORSTOM 4 stn DW 197;E, A. encarnae n. sp., holotype,MUSORSTOM 6 stn CP 464;F, A.flabelloides n. sp., from SMIB 4 stn DW 36; G, A. gemini n. sp., holotype, GEMINI stn DW 60; H, A. infinita n. sp., holotype, MUSORSTOM 4 stn DW 197; I, A. intermedia n. sp., holotype, CHALCAL 2 stn DW 76; J, A. inversa n. sp., holotype, MUSORSTOM 6 stn DW 476; K, A. laertesi n. sp., holotype, MUSORSTOM 6 stn DW 425. Scale bars: A, C, F, G, I, 10 mm; B, D, E, H, J, K, 20 mm.