COLONY MORPHOLOGY, AGE STRUCTURE, AND RELATIVE GROWTH OF 2 GORGONIAN CORALS, LEPTOGORGIA-HEBES (VERRILL) AND LEPTOGORGIA-VIRGULATA (LAMARCK), FROM THE NORTHERN GULF-OF-MEXICO

Along the northeastern Gulf of Mexico coast, Leptogorgia hebes is the predominant gorgonian at two inner shelf (22 and 27 m) sites, while Le ptogorgia virgulata dominates a third shallow (1-2 m), inshore site. T he axial skeleton of both species is composed of concentric rings whic h appeared to exhibit annual periodicity. Although age structure of th e populations differed between shelf sites, neither colony growth rate s, estimated from direct measurements of ring widths plotted on Walfor d graphs, nor overall branching complexity, determined from bifurcatio n ratios (R(b)), differed between the shelf populations. Larger indivi duals at the 27 m shelf site were simply older than those at the shall ower (22 m) shelf site. Walford plots of growth increments revealed co lony growth of the shallow inshore species to be similar to that of th e offshore species.