2.2. THE CASE STUDIES
(a)
(b)
fragments are simply the portions of colonies that survive a disturbance, but
in others the fragments appear to develop from fission of otherwise intact
colonies. As among stony corals this level of modularity can produce large
groups of genetically identical colonies each of which can then grow and
generate new colonies.
In octocorals it is the pattern by which branches are added to the colony
that controls colony form. The pattern of branching is controlled, in part,
by environmental cues, the pattern of resource supply across the colony, and
hydrodynamic forces . As among encrusting and nodular forms the mechanical disturbance of colonies as well as fission processes are also employed by
some species to generate new colonies, allowing some species to monopolize
large areas.
49
Fig.2.29a-C. Photographs of sea fans.
(a) Gorgonia venta/ina (Colombia
Caribbean, photo J. Garzon-Ferreira);
(b) Pacifigorgia agassizii (USNM collection, photo J.A.Sanchez);(c) Pacifigorgia
sp. detail (USNM collection, photo J.A.
Sanchez)
(c)