Anatomy and cnidae distinguish two species of deep-sea actinians that produce coiled, chitinous shells inhabited by hermit crabs of the genus Parapagurus. The actinian type species, Stylobates aeneus, first assigned to the Mollusca, occurs around Hawaii and Guam with P. dofleini. Stylobates cancrisocia, originally described as Isadamsia cancrisocia, occurs off east Africa with P. trispinosus. p...

, 86 (2007); 317 Science et al. Nicholas H. Putnam Repertoire and Genomic Organization Sea Anemone Genome Reveals Ancestral Eumetazoan Gene This copy is for your personal, non-commercial use only. clicking here. colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to others here. following the guidelines can be obtained by Per...

Glass microelectrodes were used to record electrical activity from thin rings cut from the column of the sea anemone Calliactis parasitica. This is the first time that pulses have been recorded from the nervous system in the column. Three pulse types were detected, types A, B and C. Type A pulses are probably associated with neurones of the through-conducting nerve net. Type B pulses may be fro...

Sea anemones (Phylum Cnidaria; Class Anthozoa, Order Actiniaria) exhibit a diversity of developmental patterns that include cloning by fission. Because natural histories of clonal and aclonal sea anemones are quite different, the gain and loss of fission is an important feature of actiniarian lineages. We have used mitochondrial DNA and nuclear intron DNA phylogenies to investigate the evolutio...

The circadian clock is a molecular network that translates predictable environmental signals, such as light levels, into organismal responses, including behavior and physiology. Regular oscillations of the molecular components of the clock enable individuals to anticipate regularly fluctuating environmental conditions. Cnidarians play important roles in benthic and pelagic marine environments a...

Astacin-like metalloproteases are ubiquitous in the animal kingdom but their phylogenetic relationships and ancient functions within the Metazoa are unclear. We have cloned and characterized four astacin-like cDNAs from the marine hydroid Hydractinia echinata and performed a database search for related genes in the draft genome sequence of the sea anemone Nematostella vectensis. These sequences...

Some photosynthetic organisms benefit from elevated levels of carbon dioxide, but studies on the effects of elevated PCO(2) on the algal symbionts of animals are very few. This study investigated the impact of hypercapnia on a photosynthetic symbiosis between the anemone Anthopleura elegantissima and its zooxanthella Symbiodinium muscatinei. Anemones were maintained in the laboratory for 1 week...

In a series of papers on the nerve net of the Actinozoa, Pantin (19350, b, c, d) showed that the decisive factor in the neuromuscular activity of these animals is an extreme development of facilitation. This is seen most readily in the transmission of excitation from the nerve net to certain muscleo, in particular the marginal sphincter of Calliactis parasitica and the longitudinal mesenteric m...