Hebella cf. scandens ( Bale, 1888 )

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 : 6

Hebella cf. scandens ( Bale, 1888)

( Fig. 1A, B )

Hebella scandens ― Boero et al., 1997: 8, Fig. 2 .

Hebella calcarata ― Leloup, 1974: 9, Fig. 6 (not Laodicea calcarata L. Agassiz, 1862 ).

Material examined. HF9, Los Gemelos, lat. -54.91942, long. -67.36308, 15.xii.2010, 12.6 m, sample C130: sterile colony on Synthecium protectum Jäderholm, 1903 (MHNG-INVE-83256). HF11, southern exit of Canal Williams, lat. -45.60000, long. -74.46667, 19.xi.2011, 8.9 m, sample C009: fertile colony on S. protectum (MHNG-INVE- 86257).

Remarks. The somewhat proximally swollen hydrothecae, tapering gradually towards a slightly everted aperture, provided basally with a thick diaphragm, as well as the large gonothecae with a four-flapped operculum, suggest that we are most probably dealing with Bale’s (1888) species. The cnidome, although quite difficult to observe in this rather scarce material, seems to be indistinguishable from that described earlier by one of us ( Galea 2013). The Chilean specimens examined by Leloup (1974), although of similar size, show hydrothecae curved basally to a varying extent, a feature possibly resulting from their epizootic habit.

Distribution in Chile. Calbuco Channel, Reloncaví Sound [ Leloup 1974, as H. calcarata (L. Agassiz, 1862) ], Los Gemelos, and Canal Williams (present records).

World records. Circumglobal ( Millard 1975), except for polar seas.

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 2. A, B: Halecium flexile Allman, 1888 — portion of stem (A) compared with H. balei Fraser, 1911 (C); detail of hydrophore and renovated hydrotheca (B), and comparison with H. balei (D). E, F: Halecium humeriformis sp. nov. — stem fragments (E); hydrophore and renovated hydrotheca (F). G, H: Halecium maximum sp. nov. — stem fragments (G); hydrophore and renovated hydrotheca (H). I ‒ L: Halecium modestum sp. nov. — stem fragments (I ‒ K); hydrophore with hydrotheca (L). M, N: Halecium platythecum sp. nov. — stem fragment (M); hydrophore and renovated hydrotheca (N). Scale bars: 300 µm (B, D, F, H, L, N) and 1 mm (A, C, E, G, I ‒ K, M).