Juvenile hormone mimics: effect on cirriped crustacean metamorphosis.

A synthetic juvenile hormone mimic has been shown to cause premature metamorphosis of the cyprid larva of an acorn barnacle in concentrations as low as 10 parts per billion in filtered seawater. The effect of a juvenile hormone mimic on a crustacean has not previously been demonstrated.

Can dynamite-blasted reefs recover? A novel, low-tech approach to stimulating natural recovery in fish and coral populations.

Throughout Southeast Asia, blast fishing creates persistent rubble fields with low coral cover and depauperate fish communities. We stabilized a 20-year-old rubble field in a Marine Protected Area in the Philippines, using plastic mesh and rock piles in replicated 17.5m(2) plots, thereby increasing topographic complexity, fish habitat, and recruitment substrate surface area. Multivariate analysis revealed fish community shifts within the rehabilitated area from that characteristic of rubble fields to one similar to the adjacent healthy reef within three years, as measured by changes in fish abundance and body size. Coral recruitment and percent cover increased over time, with 63.5% recruit survivorship within plots, compared with 6% on rubble. Our low-cost approach created a stable substrate favoring natural recovery processes. Both rehabilitation and the elimination of poaching were integral to success, emphasizing the synergism between the two and the need to incorporate both when considering mitigation.

Toxicants from mangrove plants, VI. Heritonin, a new piscicide from th mangrove plant Heritiera littoralis.

The mangrove plant Heritiera littoralis has been utilized by natives of the Philippines as a fish poison. The petroleum ether extract of this plant has shown toxicity to fish (Tilapia nilotica). A new piscicide, which was assigned the name heritonin [1], has been identified as one of the compounds with ichthyotoxicity. The structure was elucidated by spectroscopic methods.