Acryptolaria undulata, 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 : 323-324

Acryptolaria undulata n. sp.

( Figs 29 ; 30 ; 32L ; Table 30)

TYPE MATERIAL. — Norfolk Ridge. BIOCAL 1, stn DW 66, 24°55.435’- 24°54.849’S, 168°21.678’- 168°21.995’E, 515- 505 m, 3.IX.1985, 1 stem 10 mm high, holotype (MNHN-Hy.2009-0175) ; 1 stem 12 mm high, paratype (RMNH-Coel. no. 31530); 1 stem 8 mm high, paratype ( MNCN 2.03 /435) .

OTHER MATERIAL EXAMINED. — Norfolk Ridge. BIOCAL 1, stn CP 67, 24°55.443’- 24°54.176’S, 168°21.550’- 168°21.978’E, 500-510 m, 3.IX.1985, 1 fragment c. 20 mm long (RMNH-Coel. no. 35239, slide no. 826).

ETYMOLOGY. — The specific name undulata refers to the wavy form of the hydrotheca; it is an adjective, from the verb “undo” = to undulate, following the (female) genus name in declension.

ECOLOGY AND DISTRIBUTION. — Acryptolaria undulata n. sp. was collected at a depth of 500-515 m in the Norfolk Ridge area.

DESCRIPTION

Unbranched stems up to 20 mm high. Stems almost straight, forming a scarcely noticiable zigzag ( Fig. 32L ; Fig. 29A ).

Hydrothecae in approximately one plane ( Fig. 29A ), undulating with a triple curvature ( Fig. 29 ): first strongly curved outwards, then markedly bent upwards and, finally, slightly curved outwards again; hydrotheca consequently with a distinct abcauline hump. Hydrothecal diameter approximately homogeneous throughout, but decreasing basally.Moreover, the hydrotheca is slightly narrowed at the point where it becomes free and widens towards the aperture; it is adnate for less than half its adcauline length (adnate/free ratio 0.8). It has many short renovations (up to 20); the hydrothecal rim is flaring.

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

Coppinia not found.

REMARKS

Acryptolaria undulata n. sp. is unique by the shape of the hydrothecae and therefore easily recognizable. Furthermore, its nematocysts are amongst the largest known. The material from BIOCAL 1 stn CP 67 has a stolon distally, indicating the possibility to anastomose.

As stated above, Acryptolaria undulata n. sp. is undoubtedly allied to A. pseudoundulata n. sp. Even their nematocysts are of the same size. However, A. pseudoundulata n. sp. is a more robust species, with distinctly wider but shorter hydrothecae (cf. Table 31). Moreover, they differ in the shape of the hydrotheca since these are curved twice in A. pseudoundulata n. sp., instead of three times as it occurs in A. undulata n. sp. Also, whereas the diameter of the hydrothecae is clearly smaller at the aperture than at the diverging point in A. pseudoundulata n. sp., contrary conditions are found in A. undulata n. sp.

Figures

FIG. 29. — Acryptolaria undulata n. sp.: A, branch fragment showing hydrothecal arrangement; B, hydrotheca; A, from BIOCAL 1 stn CP 67; B, from BIOCAL 1 stn DW 66. Scale bar: A, 600 μm; B, 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