Oswaldella erratum Pena Cantero & 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 erratum
description
Description. Monosiphonic (occasionally polysiphonic), unbranched stems, up to 130 mm high, usually not divided into internodes. Typically, perisarc strongly developed. Angle between cauline apophyses and stem ca. 70 °. Cauline apophyses with two axillary nematophores, each provided with a much-reduced nematotheca (Fig. 4 B). Hydrocladia branched, up to third-order hydrocladia reported. First hydrocladial internode bifurcated, with two similar prongs (Fig. 4 A). Mesial-inferior nematophore on a strongly marked swelling at proximal third of internode (Fig. 4 D – E); with scale-shaped nematotheca (Fig. 4 D – F). Hydrotheca elongate, placed on middle of internode (Fig. 4 A, D – E). Abcauline wall of hydrotheca basally straight, but strongly curving adcaudally at distal part (Fig. 4 E). Hydrothecal aperture kidney-shaped (Fig. 4 C), adcaudally directed (Fig. 4 E). Gonothecae fusiform. Female gonotheca larger than male one, with subterminal, circular aperture. Male gonotheca with distal, circular aperture (Fig. 4 G).
discussion
Remarks. The most remarkable finding in relation to this species is the presence of much-reduced nematothecae in the axillary nematophores, never described before.
materials_examined
Material examined. German Antarctic Expedition ANT-XXI / 2: Stn PS 65 / 166 - 1, Polarstern, 15 December 2003, 70 ° 56.83 ’ – 70 ° 56.00 ’, 10 ° 32.61 ’ – 10 ° 30.53 ’ W (off Cape Norvegia, Weddell Sea), 338 – 253 m. Spanish Antarctic Expedition Bentart 95: Stn 24 R, Hespérides, 30 January 1995, 63 ° 58.4715 ’ S, 60 ° 51.9882 ’ W (off Trinity Island, Graham Land), 214 m (Department of Zoology, University of Valencia, BENTART 95 - 24 R).