Anthopleura minima (Sea Anemones of New Zealand)

Anthopleura minima

Description ²

Habitat
Common. Often associated with mussels near low tide level on exposed reefs. Either on the mussels or the rock between the mussels. Small ones are also found also among the tubes of fan tube worms.

Column
The base is wider than the column with an irregular flange around the edge. The column is dark pink or orange or red or brick with verrucae bumps, of the same colour, which may stick to shell fragments etc. The column is 20 to 30mm high and 10 to 15mm diameter.

Oral disc
At the edge of the disc in a collar at the top of the column are 12 to 48 pink (or sometimes white) spherules.
The oral disc is described alternately as a complex pattern from the centre of yellow/brown/grey with radiating yellow lines or as a complex pattern of light and dark green and grey from a pink/red area around the mouth to the outside of the disk.
Also "The actinopharynx itself is orange or pink with the siphonoglyphes marked by a transverse brown band. Two to five siphonoglyphs have been observed in different specimens, asymmetrically arranged" or "With radiating gold marks running from the peristome towards the bases of the tentacles"

Tentacles
In three whorls, up to about 36 tentacles described alternately as half the diameter of the oral disc, or about the same length as the oral disc. Also "They are mottled with silver and brown in a complex pattern. Directives and the first cycle of six are mostly white, with a central dark streak. The others are mostly brown on the oral side, with a few irregular white spots. Those adjacent to the inner ring of six, have the side adjacent, also white. In shape the tentacles are broad at the base, rather blunt" and "Fairly stout, tapering gently. Semi-transparent, with white bars and dots. There is a white area round the base, then a few dark lines."

Distribution
NZ wide.

Reproduction
"possible ... that it reproduces by lateral fission, although partially divided animals have never been found"

Zooxanthellae not present.

Edited version of Records of the Canterbury Museum, Vol 6, No 1, p107-8, Nov 1951
Article: The Actiniaria of New Zealand - a check-list of recorded and new species, a review of the literature, and a key to the commoner forms Part 1
By G. Parry. :

Anthopleura minima, Stuckey and Walton, 1910

Habitat
This is a firmly adherent species, often attached to mussels, or to the rock between mussel attachments.
The most common environment is in the mussel beds which are found on exposed reefs. It sometimes occurs in large numbers in such an environment, attached to the mussel shells near their attachment to the rocks, or between the mussels, on the rock itself. It is generally near low tide level. Small specimens are found also among the tubes of the serpulid Pomatoceros sp. Isolated specimens are found rarely beneath boulders at low tide level on sheltered rocky shores.

Pedal disc
The base is irregular in outline, wider than the column and with quite a distinct flange. It is pink in colour.

Column
The column is pillar-like, but very variable in shape. Colour varies from dark pink or red, to orange or brick. Verrucae are present, but are not particularly prominent, nor do they commonly appear to act as suckers, although they are able to do so. Their colour is the same as that of the column. There is a well-marked collar at the top of the column, and within it a ring of 12 (or up to 48 in large specimens) spherules. They are pink although occasionally white.

Oral Disc
The oral disc is flat in expansion with the peristome flat or slightly raised. There is a complicated pattern of gold and brown and grey, with radiating gold marks running from the peristome towards the bases of the tentacles. The actinopharynx itself is orange or pink with the siphonoglyphes marked by a transverse brown band. Two to five siphonoglyphs have been observed in different specimens, asymmetrically arranged. It seems possible from this, and from the gregarious nature of the species, that it reproduces by lateral fission, although partially divided animals have never been found.

Tentacles
The tentacles are commonly 36, or more in larger individuals. The number is variable, and there is seldom a strictly hexamerous arrangement. They are mottled with silver and brown in a complex pattern. Directives and the first cycle of six are mostly white, with a central dark streak. The others are mostly brown on the oral side, with a few irregular white spots. Those adjacent to the inner ring of six, have the side adjacent, also white. In shape the tentacles are broad at the base, rather blunt, and half the diameter of the disc.

Size
In size, height may be 2-3 cm, diameter 1-1.5 cm, tentacles 0.5 cm long.

Distribution
It has been found in large numbers at Otohuao in mussel beds (near Menzies Bay) and similarly at Wainui (Akaroa); in serpulid tubes at Taylor's Mistake; also from Menzies Bay, Portobello (Otago Harbour), St. Helier's Bay, Manukau Harbour (Auckland), and Goose Bay (Kaikoura).

An edited version of Transactions and Proceedings of the Royal Society of New Zealand 1868-1961, Art. LV., Volume 42, 1909, p543:
Notes on a Collection of Sea-anemones.
By F. G. A. Stuckey, M.A., and C. L.Walton. :

Bunodes minima, sp. nov.

Pedal Disc
Adherent to rocks; irregular in outline.

Column
Rosy pink, or light orange. Slightly higher than broad. Wrinkled. Warts few. Marginal beads white or pink.

Oral Disc
Centre rose-colour. Between this and bases of tentacles is a complicated pattern of light and dark olive-green and grey.

Tentacles
36 in number. As long as diameter of disc, or slightly more. Fairly stout, tapering gently. Semi-transparent, with white bars and dots. There is a white area round the base, then a few dark lines.

Size
We did not record the exact dimensions, but the species is smaller than B. inconspicua.

References ²

http://rsnz.natlib.govt.nz/volume/rsnz_42/rsnz_42_00_005120.html (as Bunodes minima)
Records of the Canterbury Museum Vol 6, No 1, p107-8, Nov 1951, The Actiniaria of New Zealand by G Parry

Synonyms: