Gonaxia sinuosa 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 : 416-418

Gonaxia sinuosa Vervoort, 1993

Figs 1I , 5F , 12 , 13 , 15 , 16 ; Table 3

Gonaxia sinuosa Vervoort, 1993: 179 , figs 31C–E, 35B, 37A–B, 38A.— Galea, 2016: 11 , figs 2E, 3L–N.

Material examined. KANACONO, Stn. CP 4674, MNHN-IK-2019-2086: several unbranched colonies, 1.5–5.8 cm high, some bearing ♂ gonothecae; GenBank: MZ 099709 (16S).—KANACONO, Stn. DW 4724, MNHN-IK- 2019-2070: three colonies, 9.5–10.0 cm high, all bearing ♂ gonothecae, and two of which are branched; GenBank: MZ 099708 (16S), MZ 099689 (18S), MZ 099673 (28S).—KANACONO, Stn. DW 4726, MNHN-IK-2019-2084: seven colonies, 2.2–8.0 cm high, of which two are branched; all bear either ♂ or ♀ gonothecae.—KANACONO, Stn. CP 4730, MNHN-IK-2019-2082: a branched colony, 6.5 cm high, bearing ♂ gonothecae.—KANACONO, DW4741, MNHN-IK-2019-2077: several colonies, of which one is branched, and fragments, up to 9 cm high, some sterile, and some others bearing either ♂ or ♀ gonothecae.—KANACONO, Stn. DW 4742, MNHN-IK-2019-2073: two colonies, 2.2 and 4.2 cm high, largest bearing ♂ gonothecae, while the other is sterile. —KANACONO, Stn. DW 4743, MNHN-IK-2019-2071: four colonies, 4.3–8.5 cm high, all unbranched and bearing presumably ♂ gono- thecae.—KANACONO, DW4763, MNHN-IK-2019-2078: numerous unbranched colonies, 4.0– 7.5 cm high, some bearing either ♂ or ♀ gonothecae, while some others are sterile.—KANACONO, Stn. DW 4764, MNHN-IK-2019- 2085: many unbranched colonies, 1.8–7.3 cm high, mostly bearing either ♂ or ♀ gonothecae.—KANACONO, Stn. DW 4765, MNHN-IK-2019-2083: five unbranched colonies, 4.4–7.4 cm high, bearing either ♂ or ♀ gono- thecae.—KANACONO, Stn. DW 4768, MNHN-IK-2019-2075: five colonies, 5.0– 8.5 cm high, of which two are branched, some bear ♂ gonothecae, while others bear ♀ gonothecae; GenBank: MZ 099707 (16S).—KANACONO, Stn. DW 4770, MNHN-IK-2019-2072: a 3.2 cm high, sterile colony.—KANACONO, Stn. DW 4776, MNHN-IK- 2019-2081: two colonies, of which one is 2.8 cm high and sterile, while the other is 6.5 cm high and bears ♀ gono- thecae.—KANACONO, Stn. CP 4779, MNHN-IK-2019-2079: two colonies, of which one is 4.3 cm high and bears ♀ gonothecae, while the other is 5.3 cm high and bears ♂ gonothecae.—KANACONO, Stn. DW 4782, MNHN- IK-2019-2080: two unbranched colonies, 4.4 and 7.9 cm high, both bearing ♂ gonothecae.—KANACONO, Stn. DW 4784, MNHN-IK-2019-2069: a sterile colony, 8.1 cm high, and two colony fragments, one 3.1 cm high and sterile, the other 3.2 cm high and bearing numerous ♀ gonothecae .

Remarks. This species shows a high degree of intraspecific variation that mainly relies in the shape ( Fig. 13A– C ) of, and the spacing between hydrothecae ( Fig. 12 ), giving the colonies slightly different appearances. However, all have in common their gonothecae that are free from the stem ( Figs 5F , 13D–E ). Similar observations regarding the hydrothecae were made earlier by Vervoort (1993: figs 37A–B and 38A).

Bathymetric distribution. Between 80–856 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 5. Gonothecae of several species of Gonaxia dealt with herein: G. crassicaulis Vervoort, 1993 (A: female, B: male), G. elegans Vervoort, 1993 (C), G. incisa Galea, sp. nov. (D), G. perplexa Vervoort, 1993 (E), G. sinuosa Vervoort, 1993 (F). Scale bar: 5 mm.

FIGURE 12. Gonaxia sinuosa Vervoort, 1993 (part). A–C. Portions of colonies from samples MNHN-IK-2019-2069 (A), MNHN-IK-2019-2086 (B) and MNHN-IK-2019-2071 (C), showing morphological variability. Scale bar: A–C = 1 mm.

FIGURE 13. Gonaxia sinuosa Vervoort, 1993 (continued). A–C. Hydrothecae from various colonies. D, E. Male (D) and female (E) gonothecae. From samples MNHN-IK-2019-2069 (A, E), MNHN-IK-2019-2071 (B), MNHN-IK-2019-2086 (C) and MNHN-IK-2019-2077 (D). Scale bars: A–C = 300 µm; D, E = 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).