The family Actinodendronidae Haddon, 1898 is a group of three genera of exclusively tropical Indo-Pacific sea anemones. The oral disc of these sea anemones is drawn out into a variable number of branched protrusions that make them resemble a tree. These animals are found in shallow water in sheltered places with sandy or muddy bottoms. With few exceptions, the column of these sea anemones is buried into the substratum. Only the oral disc and a crown of highly branched tentacles are visible. A few species of this family inhabit rocky substrata or even live among the coral branches. These animals are named "stinging sea anemones" due to their capacity to sting humans badly.

Actinodendronidae seems to be a monophyletic group. No other family contains anemones with such highly branched tentacles. The oral disc protrusions are branched into simple tentacles in the genus Actinostephanus, and ramified tentacles in the genera Actinodendron and Megalactis. All of the species have 24 pairs of mesenteries with strong diffuse retractors, and lack a marginal sphincter muscle. The cnidom is represented by only one type of nematocysts.

The species of Actinodendronidae are poorly described. A few descriptive paragraphs, sometimes partially in Latin and associated with diagrammatic drawings, is all we inherit from authors of some the species such as Actinodendron arboreum Quoy and Gaimard in de Blainville, 1830, A. alcyonoideum Quoy and Gaimard in de Blainville, 1830, Megalactis hemprichii Ehrenberg, 1834, and M. griffithsii Saville Kent, 1893.

TASK: to produce a monograph of the family Actinodendronidae that will include species descriptions and phylogenetic analysis of the group.

PLEA FOR DATA: I am trying to assemble a database of the variability and distribution in Actinodendronidae. The known distribution includes the Red Sea, and the tropical Indo-Pacific. This is a huge area to cover. The number of specimens in museums is small. At this moment (Aug, 2001), I have about 300 records (lots observed from museums, specimens observed alive, or from pictures). Any record that can be documented with at least a photograph and location (preferably also depth) would be very helpful to accomplish this goal. I kindly ask to help me to go through YOU to those wonderful locations which otherwise I could not investigate. You can contact me by e-mail at adorian@ku.edu.