Herbivores often specialize on particular hosts that provide both food and shelter from natural enemies. It is thus often unclear whether a plant’s value as a food or its value as a safe shelter has played a larger role in selecting for specialization. Decorator crabs offer a novel opportunity to investigate the relative effects of diet vs. natural enemies in selecting for specialization becaus...

Freshly released eggs of the marine brown alga Dictyota dichotoma secrete a substance that attracts spermatozoids. This compound has been identified as n-butyl-cyclohepta-2,5-diene. It is closely related to attractants in several other brown algae and confirms that a relation exists between phylogeny and attractant compounds.

the present study was intended to standardize the protocol for the synthesis of silver nanoparticles (agnps) using aqueous extract of dictyota bartayresiana j.v. lamouroux and evaluate cytotoxic potentials using brine shrimp bio-assay activity and trypan blue dye exclusion method. the reduction of pure ag+ ions was monitored by measuring the uv-vis spectrum of the solution at 200-900 nm and the...

Photosynthates released by benthic primary producers (BPP), such as reef algae and scleractinian corals, fuel the dissolved organic carbon (DOC) production on tropical coral reefs. DOC concentrations near BPP have repeatedly been observed to be elevated compared to those in the surrounding water column. As the DOC release of BPP increases with increasing light availability, elevated DOC concent...

Two new species of the genus Rissoella Gray, 1847 are described from Venezuela, one from the National Park Morrocoy, Rissoella morrocoyensissp. n. and the other from the Wildlife Refuge Isla de Aves, Rissoella venezolanicolasp. n.Rissoella morrocoyensissp. n. has a deep umbilicus (partly closed), preumbilical cord, black head, hypobranchial gland marked by a pale yellow boomerang-shaped ribbon ...

Abstiact: When offered single species of seaweeds in excess amounts, the sea urchin Arbuciapunctulata (Lamarck) Philippi consumed significantly more Gracilana folijr,a (Forsskal) Borgrsen and Codium z3thmocladium Vickers than Sargassum filipendula C. Agardh, Padina vickersiae Hoyt, or Dictyota dichotomu (Hudson) Lamouroux. When all five species were offered to urchins simultaneously, patterns o...

Marine brown alga Dictyota dichotoma (Dictyotaceae) collected from the Karachi coast of the Arabian Sea has yielded three new C-16 oxidized seco-dolastanes (diterpenoids) named dichotenol-A, B and C. Their structures have been characterized with the aid of 2D-NMR spectroscopic techniques.