Gonaxia bulbifera 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 : 404

publication ID	https://doi.org/ 10.11646/zootaxa.5004.3.1
publication LSID	lsid:zoobank.org:pub:0C4DFAA3-5822-456B-916B-84A7BABEB98F
persistent identifier	https://treatment.plazi.org/id/03AA0A13-FF95-B665-FF0D-FB9BFBBB1DEE
treatment provided by	Plazi
scientific name	Gonaxia bulbifera Vervoort, 1993
status

Treatment

Figs 1A View FIGURE 1 , 2A–C View FIGURE 2 , 3A–C, E, F View FIGURE 3 , 15 View FIGURE 15 , 16 View FIGURE 16 ; Table 3

Gonaxia bulbifera Vervoort, 1993: 131 , figs 12B, 13.

Material examined. KANADEEP, Stn. DW4977, MNHN-IK-2019-2056: two colonies, 2.0 and 2.4 cm high, both bearing ♀ gonothecae; GenBank: MZ 099691 View Materials (16S).—KANADEEP, Stn. DW4979, MNHN-IK-2019-2060: two colonies, 1.7 and 1.9 cm high, smallest bearing ♀ gonothecae, largest sterile; GenBank: MZ 099692 View Materials (16S).— KANADEEP, Stn. DW5042, MNHN-IK-2019-2055: a 1.1 cm high colony fragment bearing ♀ gonothecae.—Com- parison material: MUSORSTOM 8, Stn. CP1083, MNHN-IK-2012-16537 and -16538: Gonaxia nova Galea, 2016, type series, as described in Galea (2016: 16).

Remarks. The present material, especially that from sample MNHN-IK-2019-2056 ( Figs 2A View FIGURE 2 , 3A, E View FIGURE 3 ), agrees well with the original account. However, intraspecific variability, mostly dealing with the morphology and position of the hydrothecae, could be noted among specimens from different stations: slenderer thecae occurred in sample MNHN-IK-2019-2055 ( Figs 2C View FIGURE 2 , 3C View FIGURE 3 ) and thecae more distant from one another were met with in sample MNHN- IK-2019-2060 ( Fig. 2B View FIGURE 2 ). Only female gonothecae have been observed in the material at hand ( Fig. 3E, F View FIGURE 3 ), and they conform to those described and illustrated by Vervoort (1993).

As noted by Galea (2016: 19), G. bulbifera and G. nova Galea, 2016 are morphologically similar. Part of the type series of the latter has been reexamined in the frame of the present study, and the opinion expressed earlier that G. nova has larger hydrothecae and gonothecae could be confirmed (compare Figs 3A–C and 3D View FIGURE 3 , and Figs 3E–F and 3G View FIGURE 3 , respectively). In addition, it should be noted that the inflexion point of the abaxial wall of the hydrotheca is situated halfway in G. nova (conferring the theca a decidedly arched appearance, Figs 2D View FIGURE 2 , 3D View FIGURE 3 ), and in the proximal third in G. bulbifera ( Fig. 2A–C View FIGURE 2 ); moreover, the free adaxial wall of the former varies from straight, or nearly so, to slightly concave halfway ( Fig. 3A–C View FIGURE 3 ), while it is constantly convex all the way long in G. nova ( Fig. 3D View FIGURE 3 ). Last but not least, the gonothecae of G. bulbifera ( Fig. 3E, F View FIGURE 3 ) observed here are devoid of the dense proximal striae reported by Galea (2016) in G. nova ( Fig. 3G View FIGURE 3 ).