| Arachnactidae | |
|---|---|
 | |
| The ceriantharianArachnanthus sarsi, Rathlin Island, Northern Ireland. | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Subphylum: | Anthozoa |
| Class: | Hexacorallia |
| Order: | Ceriantharia |
| Suborder: | Penicillaria den Hartog, 1977 |
| Family: | Arachnactidae McMurrich, 1910 |
| Genera | |
See text | |
Arachnactidae is afamily oftube-dwelling anemones in the orderCeriantharia. It is the only family in the monotypic orderPenicillaria and comprises around 38 species. They differ from other ceriantharians in the makeup of their cnidome (the types ofcnidocyte 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.[1]
TheWorld Register of Marine Species includes the following genera in the family :[2]
