Oswaldella delicata Pena Cantero, Svoboda & Vervoort 1997
- Dataset
- SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Cnidaria
- class
- Hydrozoa
- order
- Leptothecata
- family
- Kirchenpaueriidae
- genus
- Oswaldella
- species
- Oswaldella delicata
description
Description. Monosiphonic, unbranched stems, up to 60 mm high, divided into internodes. Angle between cauline apophyses and stem ca. 45 °. Cauline apophyses with single axillary nematophore, emerging through perisarc hole provided with very short collar-shaped nematotheca (Fig. 2 B, C). Hydrocladia unbranched (Fig. 2 A), some bifurcated. First hydrocladial internode bifurcated, with two similar prongs. Mesial superior nematophore emerging behind free part of adcauline hydrothecal wall. Mesial inferior nematophore on a strongly marked swelling at proximal third of internode; with well-developed, nail-shaped nematotheca (Fig. 2 D – F). Hydrotheca elongate, placed on middle of internode. Adcauline wall with distinct free portion. Abcauline hydrothecal wall roughly straight, but basally convex (Fig. 2 E). Hydrothecal aperture circular, more or less perpendicular to long axis of internode (Fig. 2 D – E); rim even. Gonothecae fusiform with subterminal circular aperture.
discussion
Remarks. Our study has confirmed the presence of a single axillary nematophore in the cauline apophyses, as previously described (Peña Cantero et al. 1997; Peña Cantero & Vervoort 2004). However, it is noteworthy that our study has provided evidence of the presence of a little-developed, previously unnoticed, collar-shaped nematotheca associated with that nematophore (Fig. 2 B – C).
materials_examined
Material examined. Spanish Antarctic Expedition Bentart 95: Stn 28 A, BIO Hespérides, 2 February 1995, 62 ° 12.1297 ’ S, 60 ° 23.1833 ’ W (South Shetland Islands, north of Livingston Island), 126 m (Department of Zoology, University of Valencia, BENTART 95 - 28 A).