Holotype: NMV F101644, fertile colony on stem of Gymnangium ascidioides, Cape le Grand, Western Australia, depth 17 m. Paratype: WAM Z29950, infertile colony on stem of Gymnangium superbe, New Island, Western Australia, depth 20 m.
This species is named ‘minuta’ in recognition of its small size.
Hydranths arising at intervals from an unbranched tubular stolon creeping up stem and along hydrocladia of host; caulus short, without demarcation from hydrorhiza, straight or bent, to 0.3 mm long, expanding a little distally below hydranth, perisarc weakly rugose or smooth, perisarc of stolon and caulus thin and fragile. Hydranths to 0.5 mm long (preserved), body cylindrical with dome-shaped hypostome surrounded by four to six rather short branched aboral tentacles in two whorls, each tentacle with three or four opposite pairs of short capitate side branches, a terminal capitalum on branch; four short capitate oral tentacles. Capitula 300-400 µm diameter composed of a globular cluster of nematocysts; some hydranths also with a few large scattered nematocysts enclosed in a blister of tissue between aboral and oral tentacles; same kinds of nematocysts also scattered throughout hydrorhiza and caulus.
Gonophore a globular fixed sporosac, one on hydranth on a short pedicel among basal aboral tentacles, gonophore 500 µm diameter (preserved), an aureole of large nematocysts (categories 1 and 3 below) scattered on top third of body.
Cnidome comprising three kinds of nematocysts:
1) Stenoteles, capsule subspherical to ovoid, 11-13 x 10 µm, in capitalum of tentacles and on gonophores.
2) Stenoteles, capsule subspherical to ovoid, 7 x 5 µm, in capitalum of tentacles.
3) Mesobasic euryteles, capsule oval, 3~34 x 18-21 µm, on body of hydranth, on gonophore, in coenosarc of caulus and hydrorhiza.
Colour: White
Western Australia.
Subtidal, epizoic on other hydroids.