Close encounters of the jelly kind

Naturally Occurring Organohalogen Compounds-A Comprehensive Review

The present volume is the third in a trilogy that documents naturally occurring organohalogen compounds, bringing the total number-from fewer than 25 in 1968-to approximately 8000 compounds to date. Nearly all of these natural products contain chlorine or bromine, with a few containing iodine and, fewer still, fluorine. Produced by ubiquitous marine (algae, sponges, corals, bryozoa, nudibranchs, fungi, bacteria) and terrestrial organisms (plants, fungi, bacteria, insects, higher animals) and universal abiotic processes (volcanos, forest fires, geothermal events), organohalogens pervade the global ecosystem. Newly identified extraterrestrial sources are also documented. In addition to chemical structures, biological activity, biohalogenation, biodegradation, natural function, and future outlook are presented.

Swimming and feeding in Periphylla periphylla (Scyphozoa, Coronatae)

Some western Norwegian fjords host extraordinarily abundant and persistent populations of the mesopelagic, coronate scyphomedusa, Periphylla periphylla. In these environments, from late autumn to spring, the medusae undertake regular diel vertical migrations into surface waters. From unique observations obtained with a remotely operated vehicle (ROV), including observations made without artificial light, we observed that 90% of the medusae swam with their tentacles in aboral position. Stomach content analyses of surface-collected specimens revealed that the medusae ate mainly calanoid copepods, but ostracods and large euphausiids were also prominent components of their diets. The clearance rate potential of P. periphylla, assessed from in situ observations and stomach contents, was comparable to that of similar-sized, epipelagic gelatinous species. Our findings suggest that P. periphylla behave as active predators in surface waters.