''Anthopleura hermaphroditica'', also known as the small brown sea anemone, is a small

anemone ''Anemone'' () is a genus of flowering plants in the buttercup family Ranunculaceae. Plants of the genus are commonly called windflowers. They are native to the temperate and subtropical regions of all regions except Australia, New Zealand, and ...

about 10 mm wide in diameter and very brown in colour. It is native to the waters around Chile and New Zealand. The brownish tinge of its outer surface makes it much harder to distinguish and find unlike some of the other sea anemones. This particular class of anemone can be seen under water as a small brown ring in soft fine sediment and slightly submerged. This brown anemone has quite a high tolerance to changes in

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

and to a high concentration of organic matter in the water.

Feeding

The small brown anemone feeds on plankton and small animals.

Habitat

The small brown anemone is distributed throughout estuaries in current-free areas. They all usually found attached to cockles who with they form a

commensal Commensalism is a long-term biological interaction (symbiosis) in which members of one species gain benefits while those of the other species neither benefit nor are harmed. This is in contrast with mutualism, in which both organisms benefit f ...

relationship as the anemone gets protection and the cockle becomes more camouflaged and so can hide better from predators such as the mud flat whelk (''Cominella glandiformis'') or sea gulls.

Reproduction

Fertilization is external and the

zygote A zygote (; , ) is a eukaryote, eukaryotic cell (biology), cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individ ...

develops into a pear-shaped

planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores, which are not related to cnidarians at all. Some groups of Nemerteans also produce larva ...

which attaches to rocks or solid substrate and develops into a young adult.

References

* * Animals described in 1899 Actiniidae {{Actiniaria-stub