Hydrodendron arboreum (Allman 1888)
- Dataset
- Hydroids of the BANZARE expeditions, 1929 – 1931: the family Haleciidae (Hydrozoa, Leptothecata) from the Australian Antarctic Territory
- Rank
- SPECIES
Classification
- kingdom
- Animalia
- phylum
- Cnidaria
- class
- Hydrozoa
- order
- Leptothecata
- family
- Haleciidae
- genus
- Hydrodendron
- species
- Hydrodendron arboreum
description
Description. Hydrorhiza a tangle of thin, tubular, rugose stolons Stem (or branch) fragments 10 - 20 mm long, thick and woody, irregularly fascicled; ultimatebranches monosiphonic; each new branch arising from side of a hydrophore; basal internode of some branches very long with several proximal constrictions, succeeding branch Internodes moderately long but variable, walls smooth, increasing slightly in diameter distally to hydrophore, nodes oblique to transverse, sloping away from hydrotheca, varying from a deep septum to a mere narrowing in perisarc, a tumescence above and often below node; longer internodes often with several weak proximal twists.
description
Figure 11 A – C
discussion
Remarks. Many hydrothecae are damaged and reduced to a short collar just above the diaphragm. The few undamaged nematophores confirm the identity of the material as Hydrodendron arboreum Allman (1888). Allman (1888) and Totton (1930) describe large colonies to 25 cm high; the present fragmentary material may be branches of a similarly large colony.
distribution
Distribution. Exclusively Antarctic – Kerguelens, 192 m, McMurdo Sound 18 – 550 m, Gauss Station, Palmer Archipelago 92 m and Commonwealth Bay 100 – 545 m.
materials_examined
Material examined. NMVF 147474, Station 105, five microslides displaying branch fragments; some preserved infertile fragments. NMV F 147475, Station 107, one microslide of two branch fragments; some preserved fragmental material.