Halecium corrugatissimum Trebilcock, 1928

Galea, Horia R., Schories, Dirk, Försterra, Günter & Häussermann, Verena, 2014, New species and new records of hydroids (Cnidaria: Hydrozoa) from Chile, Zootaxa 3852 (1), pp. 1-50 : 10-11

Halecium corrugatissimum Trebilcock, 1928

( Fig. 1 S)

Material examined. Corral, Chaihuin/Huiro, lat. -39.95000, long. -73.61667, 27.x.2011, 8‒ 10 m, sample S07: five minute stems, each ca. 1.5 mm high, carrying one or two female gonothecae, on alga (MHNG-INVE-86209).

Remarks. For the latest description and synonymy, see Schuchert (2005). Each female gonotheca in the present material carries 4 or 5 spherical oocytes (180–215 µm in diameter). The hydrothecal rim is distinctly everted, and this feature could also be observed upon a re-examination of the New Zealand material studied by Schuchert (P. Schuchert, pers. comm.).

3. The cnidomes in samples from Chile and Tristan da Cunha are identical to that illustrated by Galea et al. (2009, Fig. 4 M) for a material that we assign now to S. bilabiata , as well as to that of S. pedunculata ( Jäderholm, 1904) from Antarctica [see Galea & Schories (2012b), Fig. 3Z3].

4. The type material of this species was re-examined and illustrated by Hartlaub (1905, Figs U1–W1).

Distribution in Chile. The present material from Corral is the first Chilean record, as well as the first record of the species outside its known range of distribution.

World records. New Zealand ( Schuchert 2005).

Figures

FIGURE 1. A, B: Hebella cf. scandens (Bale, 1888) — hydrotheca (A); gonotheca (B). C ‒ D: Hebella striata Allman, 1888 — hydrotheca (C); gonotheca (D). E, G, H: Phialella? falklandica Browne, 1902 — portion of erect stem (E) compared with that of P. quadrata (Forbes, 1848) (F); gonotheca seen laterally (G) and apically (H), compared with those of P. quadrata (I, stolonal; J, borne of stem). K, L: Silicularia? bilabiata (Coughtrey, 1876) — two hydrothecae (K); female gonotheca (L). M ‒ O: Silicularia rosea Meyen, 1834 — two hydrothecae (M) compared with specimens from Tristan da Cunha assigned to S. hemisphaerica (Allman, 1888) (P); female (N) and male (O) gonothecae, compared to homologous gonothecae (Q and R, respectively) from Tristan. S: Halecium corrugatissimum Trebilcock, 1828 — small stem with female gonotheca. Scale bars: 300 µm (A, B, E, F, S), 500 µm (C, D, G ‒ J), and 1 mm (K ‒ R).

FIGURE 4. A ‒ F, M: Cnidomes of some Halecium species discussed herein— H. flexile Allman, 1888 (A); H. balei (B); H. humeriformis sp. nov. (C); H. maximum sp. nov. (D); H. tristaniensis sp. nov. (E); H. modestum sp. nov. (F). G: Halecium pallens Jäderholm, 1904 — female gonotheca. H ‒ M: Halecium tehuelchum (d’Orbigny, 1842) — fragments of colonies (H), primary hydrophore and renovated hydrotheca (I); female gonotheca (J) and shape variation (K); male gonothecae (L); cnidome (M). Scale bars: 10 µm (A ‒ F, M); 300 µm (I, J, L), 500 µm (G, K), 1 mm (H).