Adamsia is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sea anemones in the
family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Hormathiidae

Hormathiidae

Hormathiidae is a family of sea anemones in the class Anthozoa.-Genera:Genera in this family include:* Actinauge Verrill, 1883* Adamsia Forbes, 1840* Allantactis Danielssen, 1890* Amphianthus R...

. Species in this genus are mutually symbiotic

Symbiosis

Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 with hermit crabs. The anemone gets a place to live and discarded scraps of the crab's food in exchange for its help in the crab's defence. As these anemones grow, they secrete a horny membrane, known as a carcinoecium, which overlies the crab's original snail shell and expands the living space of the crab. This means the anemone does not have to change substrate and the crab does not have to seek a larger shell as they both grow.

Species

Species within the genus include:

• Adamsia fusca (Quoy & Gaimard, 1833)
• Adamsia involvens McMurrich, 1893
• Adamsia obvolva Daly et al., 2004
• Adamsia palliata
  Adamsia palliata
  Adamsia palliata is a species of sea anemone in the family Hormathiidae. It is usually found growing on a gastropod shell inhabited by the hermit crab, Pagurus prideaux...
  
  (Fabricius, 1779)
• Adamsia rondeletti (Delle Chiaje, 1822)
• Adamsia sociabilis Verrill, 1882
• Adamsia carciniopados (Otto, 1823) (nomen dubium)