Arachnactidae is a
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
of
tube-dwelling anemone
Tube-dwelling anemones or ceriantharians look very similar to sea anemones but belong to an entirely different Class (biology), class of anthozoans. They are solitary, living buried in soft sediments. Tube anemones live inside and can withdraw i ...
s in the order
Ceriantharia. It is the only family in the monotypic order Penicillaria and comprises around 38 species. They differ from other ceriantharians in the makeup of their cnidome (the types of
cnidocyte
A cnidocyte (also known as a cnidoblast or nematocyte) is an explosive cell containing one large secretory organelle called a cnidocyst (also known as a cnida () or nematocyst) that can deliver a sting to other organisms. The presence of this c ...
present), the relative sizes of the oral discs and the shape and structure of the mesenteries. These tube anemones dwell in parchment-like tubes immersed in soft sediment, and have two whorls of tentacles, the outer ones being much longer than the inner ones.
Genera
The
World Register of Marine Species includes the following genera in the family :
[Molodtsova, T. (2015)]
Arachnactidae McMurrich, 1910.
Accessed through: World Register of Marine Species on 2016-02-10
* ''
Anactinia''
Annandale, 1909
* ''
Arachnactis''
Sars, 1846
* ''
Arachnanthus''
Carlgren, 1912
* ''
Dactylactis''
Van Beneden, 1897
* ''
Isapiactis''
Carlgren, 1924
* ''
Isarachnactis''
Carlgren, 1924
* ''
Isarachnanthus''
Carlgren, 1924
* ''
Isovactis''
Leloup, 1942
* ''
Ovactis''
Van Beneden, 1897
* ''
Paranactinia''
Carlgren, 1924
References
Ceriantharia
Anthozoan orders
{{Anthozoa-stub