Gonaxia cf. intermedia Vervoort, 1993

Galea, Horia R. & Maggioni, Davide, 2021, An integrative study of some species of Gonaxia Vervoort, 1993 from off New Caledonia, with the establishment of Gonaxiidae as a new family of thecate hydroids (Cnidaria: Hydrozoa), Zootaxa 5004 (3), pp. 401-429 : 415

Gonaxia cf. intermedia Vervoort, 1993

Figs 1G , 10 , 15 , 16 ; Table 3

Gonaxia intermedia Vervoort, 1993: 157 , figs 23E, 24D, 25A–C, 26A.— Galea, 2016: 9 , figs 2D, 3G–K.

Material examined. KANADEEP, Stn. DW4945, MNHN-IK-2015-2671: a 4.7 cm high, sterile colony; GenBank: MZ 099702 (16S).

Remarks. This sterile material is only provisionally assigned to G. intermedia Vervoort, 1993 based on morphological similarities of its hydrothecae, despite their being more distant from one another compared to the original account (a similar variation was also observed in G. sinuosa Vervoort, 1993 , see under that species). However, their size approaches that of the holotype material (free adaxial wall 335–360 µm vs. 340–375 µm; adnate adaxial wall 300–335 µm vs. 230–250 µm; abaxial wall 400–470 µm vs. 320–370 µm; maximum width 220–240 µm vs. 220–235 µm; diameter at rim 150–165 µm vs. 135–150 µm).

Bathymetric distribution. Between 108–630 m ( Vervoort 1993; Galea 2016; present study).

Figures

FIGURE 1. Species of Gonaxia dealt with in this study: G. bulbifera Vervoort, 1993 (A), G. crassicaulis Vervoort, 1993 (B), G. crusgalli Vervoort, 1993 (C), G. elegans Vervoort, 1993 (D), G. errans Vervoort, 1993 (E, unbranched form), G. incisa Galea, sp. nov. (F), G. cf. intermedia Vervoort, 1993 (G), G. perplexa Vervoort, 1993 (H), G. sinuosa Vervoort, 1993 (I), G. solenoscyphoides Galea, sp. nov. (J). Scale bar: 1 cm.

FIGURE 10. Gonaxia cf. intermedia Vervoort, 1993. A. Portion of colony. B. Hydrotheca. Both from sample MNHN-IK-2015- 2671. Scale bars: B = 300 µm; A = 1 mm.

FIGURE 15. Phylogenetic hypothesis for Gonaxia species based on a 16S dataset. Numbers at nodes show maximum likelihood bootstrap values, Bayesian posterior probabilities, and maximum parsimony bootstrap values, respectively.

FIGURE 16. Phylogenetic hypothesis for the position of the Gonaxiidae Maggioni, fam. nov. within Macrocolonia, based on a multi-locus dataset. Numbers at nodes show maximum likelihood bootstrap values, Bayesian posterior probabilities, and maximum parsimony bootstrap values, respectively, and are shown only when at least two analyses demonstrated high support (> 0.9 for Bayesian posterior probabilities and> 75 for bootstrap values).