Halopteris plumosa Galea & Schories, 2012a

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 : 45

Halopteris plumosa Galea & Schories, 2012a

( Fig. 8 N, O)

Material examined. Niebla, Bonifacio, lat. -39.68333, long. -73.36667, 08.viii.2012, 14 m, sample 07: two cormoids, one bearing male and the other female gonothecae (MHNG-INVE-86226).

Remarks. This is the first finding of the gonothecae of this species. They are given off singly or in pairs, slightly laterally, below the stem hydrothecae. Female ( Fig. 8 N) ca. 860 µm long and 455 µm wide, basally ventricose, longitudinal axis S-shaped, aperture perpendicular to it; borne on a two-pieced pedicel ca. 140 µm long; aperture semi-circular, ca. 155 µm wide, closed by thin layer of perisarc; a transverse septum near base of gonotheca; two bithalamic nematothecae inserted between the basal septum and origin of gonotheca from pedicel; upper chambers of nematothecae with lowered inner walls. Male gonothecae ( Fig. 8 O) ca. 725 µm long and 335 µm wide, elongate-ovoid, tapering basally and slightly curved there; aperture distal, circular, ca. 145 µm wide, closed by thin layer of perisarc; a two-segmented, 80–95 µm long pedicel basally.

The characteristic shape of the female gonotheca recalls that of H. minuta ( Trebilcock, 1928) , as illustrated by Schuchert (1997).

Distribution in Chile. From Punta de Choros in the North to Corral in the South ( Galea & Schories 2012a, present study).

World records. Occurs in Argentina (see Galea & Schories 2012a).

Figures

FIGURE 8. A ‒ D: Symplectoscyphus unilateralis (Lamouroux, 1824) — stem fragment (A); hydrotheca (B); gonotheca in frontal (C) and lateral (D) views. E ‒ H: Symplectoscyphus sp. — colony fragment (E); hydrotheca in lateral (F) and apical (G) views; gonotheca (H). I, J: Staurotheca jaederholmi Stechow, 1920 — colony fragment (I); gonothecae (J). K ‒ M: Parascyphus simplex (Lamouroux, 1816) — stem fragment (K); hydrotheca (L) and detail of aperture (M). N, O: Halopteris plumosa Galea & Schories, 2012 a—female (N) and male (O) gonothecae. Scale bars: 200 µm (A, B, F, G), 300 µm (C, D, L ‒ O), 500 µm (H, K), 1 mm (E, I, J).