Gonaxia compacta 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

Gonaxia compacta Vervoort, 1993

Figs 2C , 3 E–F

Gonaxia compacta Vervoort, 1993: 135 , figs 8c, 14a–b, 15a.

Material examined

BATHUS 4: Stn. DW923, a single, 6 cm high colony bearing an abortive gonotheca, as well as a row of incipient gonothecae, highly obscured by the accessory tubes of the stem (MNHN-IK- 2012 -16523).

Remarks

As already stated by Vervoort (1993), the hydrothecae of this species bear an obvious resemblance to those of G. amphorifera , G. ampullacea , and G. sinuosa , but it could be readily distinguished from them on the account of the absence of a pit formed by the free adaxial wall with the internode ( Fig. 3E ). Only an abortive gonotheca, arising from within the first hydrotheca of a cladium ( Fig. 3F ), was found. Several successive, elongate masses among the accessory tubes of the stem suggest the imminent formation of normal gonothecae.

Geographical distribution

New Caledonia ( Vervoort 1993; present study).

Figures

Fig. 2. ― A. Gonaxia amphorifera Vervoort, 1993 (SMIB 6, Stn. DW127), portion of stem with cladium. ― B. Gonaxia ampullacea Vervoort, 1993 (BATHUS 4, Stn. DW914), portion of stem with cladia. ― C. Gonaxia compacta Vervoort, 1993 (BATHUS 4, Stn. DW923), portion of stem with cladium. ― D. Gonaxia intermedia Vervoort, 1993 (BATHUS 4, Stn. CP906), portion of stem with cladium. ― E. Gonaxia sinuosa Vervoort, 1993 (SMIB 4, Stn. DW40), portion of stem with cladia. Scale bar: A–E = 1 mm.

Fig. 3. ― A–B. Gonaxia amphorifera Vervoort, 1993 (SMIB6, Stn. DW127). A. Two successive cladial internodes with their hydrothecae. B. Portion of stem with male gonothecae. ― C–D. Gonaxia ampullacea Vervoort, 1993 (BATHUS 4, Stn. DW914). C. Two successive cladial internodes with their hydrothecae. D. Portion of stem with male gonothecae. ― E–F. Gonaxia compacta Vervoort, 1993 (BATHUS 4, Stn. DW923). E. Two successive cladial internodes with their hydrothecae. F. Abortive gonotheca (of undetermined sex) originating from within a hydrotheca. ― G–K. Gonaxia intermedia Vervoort, 1993 (BATHUS 4). G. Two successive cladial internodes with their hydrothecae (Stn. CP906). H. Portion of stem with male gonothecae (Stn. CP906). I. Portion of stem with female gonothecae (Stn. CP906). J–K. Abortive gonothecae arising from hydrothecal lumina (Stn. DW902). ― L–N. Gonaxia sinuosa Vervoort, 1993 (SMIB 4, DW40). L. Two successive cladial internodes with their hydrothecae. M–N. Two female gonothecae. Scale bars: A, C, E, G, L = 300 µm; B, D, F, H–K, M–N = 1 mm.