Lion Rock, Piha, 2016: this clip is a little
over-exposed. In the top left corner there is a
solitary ascidian and below that another
?dead solitary ascidian covered in
athecate hydroids.
Piha, Jan 2017.
The striped anemone, Diadumene neozelanica* is a smallish anemone (~20 across the disc) found on the lower shore on exposed coasts throughout New Zealand. They get their common name from the light and dark brown vertical stripes on the anemone’s stalk. There are many tentacles, these are quite long and fine, and can be orange/beige in colour. They possess an inner ring of blunt-tipped catch tentacles and these are diagnostic for this species.
The plumose anemone Mimetridium cryptum, Hand 1961 is very similar, but doesn't have these catch tentacles. Apparently, both species can reproduce asexually and form large patches. The problem here is that I have imagery where there are anemones in a large patch, some with the catch tentacles and some without, so at the moment I'm not sure how reliable this feature is.
Piha, Jan 2017
Very little appears to be known regarding the ecology of striped anemones. They appear to like the shade and don't seem to be found in open sunlight. It's interesting that they are orange/beige in colour, as these are colours which absorb higher wavelengths of light; those which can penetrate deeper into the water or into more shaded areas. It may mean that they have photosynthetic zooxanthellae, but this is currently unknown.
Moturiki Island, Mt. Maunganui, 2016.
Moturiki Island, Mt. Maunganui, 2016.
* (Carlgren, 1924)
More info:
de Cook, S. (2010). New Zealand Coastal Marine Invertebrates 1. Canterbury University Press.
Morton, J. A., Miller, M. E. (1968). The New Zealand Sea Shore. Collins.
