Distribution and prevalence of coral diseases in the Veracruz Reef System, Southern Gulf of Mexico.

Ten reefs of the Veracruz Reef System (VRS) were surveyed to evaluate the distribution and prevalence of diseases that affect stony corals. Total disease prevalence on corals in the VRS was 4.8%. Seven diseases affecting 6 coral genera (4 of which are the most abundant) were observed in 85.2% of the evaluated sites. As observed in other reefs of the Caribbean, dark spots disease had the highest prevalence (2.9%) and widest distribution. The incidence of disease showed a patchy distribution, with prevalence being significantly higher on the reef flats than on the windward and leeward sides.

Short-term aggressive behavior in scleractinian corals from La Blanquilla reef, Veracruz Reef System.

The short-term aggressive behavior of scleractinian corals from La Blanquilla Reef, Veracruz Reef System, Gulf of Mexico was determined. Unilateral aggression, bilateral aggression and indifference were observed through experimental interspecific encounters in situ, in aquarium conditions and through direct observation of natural encounters on the reef. Species were characterized as highly aggressive, moderately aggressive and not very aggressive establishing a hierarchy with two competitive rings representing similar aggressive abilities among some species. Most observations of aggression were of extracoelenteric digestion. Mussa angulosa was the most aggressive species and Oculina diffusa the least. Apparently there is a direct relationship among aggressiveness and relative coverage as three of the most abundant corals at depths of 4-9 m Montastraea cavernosa, Colpophyllia natans and Montastraea annularis, are all highly aggressive, have massive growth and have a high relative coverage. Siderastrea siderea is the only dominant species that was not ranked as highly aggressive; its high coverage is due to other reasons.