Gonaxia intermedia Vervoort, 1993

Galea, Horia R., 2016, Notes on some sertulariid hydroids (Cnidaria: Hydrozoa) from the tropical western Pacific, with descriptions of nine new species, European Journal of Taxonomy 218, pp. 1-52 : 9-11

publication ID	https://doi.org/ 10.5852/ejt.2016.218
publication LSID	lsid:zoobank.org:pub:A4D7AA38-D18F-4604-A5E0-D965637BD9F8
DOI	https://doi.org/10.5281/zenodo.3853783
persistent identifier	https://treatment.plazi.org/id/3D2E87D5-F806-FF8C-FDA4-FB04FD54FD8A
treatment provided by	Valdenar
scientific name	Gonaxia intermedia Vervoort, 1993
status

Treatment

Figs 2D View Fig , 3 View Fig G–K

Gonaxia intermedia Vervoort, 1993: 157 , figs 23e, 24d, 25a–c, 26a.

Material examined

BATHUS 4: Stn. DW902, several colonies and fragments, up to 9.5 cm high, mostly fertile, bearing male gonothecae (MNHN-IK- 2012 -16524); Stn. CP 906, a total of twelve fertile colonies (10 male and 2 female), 4–6 cm high (MNHN-IK- 2012 -16525).

Remarks

In some colonies, the length of cladia reaches as much as 2.8 cm, and each may bear up to 116 hydrothecae. Aberrant secondary cladia, as those occurring in specimens from Stn. DW902, are given off from either within some cladial hydrothecae ( Fig. 3J View Fig ), or from short, auxiliary cladial tubes running parallel to the proximal parts of the axes of cladia.

Both male and female colonies are present in the material in hand. As stated by Vervoort (1993), the gonothecae of this species resemble those of G. amphorifera and G. ampullacea through their general shape and nearly fully adnate condition. They seem to originate from below the axillar hydrothecae. The distal part of a gonotheca overlaps the proximal part of the following one, though their bodies never fuse with each other. Their apertures (50–65 µm wide in males, and 250–290 µm wide in females) are mounted on raised cones situated near the distal ends of their bodies. In the male colonies, the gonothecae are so obscured by the numerous auxiliary tubes running parallel to the stem, that only the tips of their neck regions protrude from the strongly fascicled mass which composes the stems. In one male specimen (from Stn. CP906) with otherwise normal gonothecae, an elongate, abortive gonotheca, with two distal apertures, is given off from the lumen of a cladial hydrotheca The occurrence of such gonothecae is considerable in the material from Stn. DW902, and specimens with one ( Fig. 3K View Fig ), two ( Fig. 3J View Fig ), or exceptionally three apertures could be seen. These so called abortive gonothecae may prove fully functional, as they are provided with apertures. However, their lumina are empty in the specimens in hand, and this assumption could not be checked at this stage.

Geographical distribution

New Caledonia ( Vervoort 1993; present study).