Cnidarians of Zihuatanejo

PHYLUM CNIDARIA

-Sea Anemones and Corals (Class Anthozoa)

-Octocorals (Subclass Octocorallia)

-Plexaurid Sea Fans (Family Plexauridae)

-Genus Muricea

The genus Muricea is a group of gorgonian (soft) corals commonly known as sea fans. These corals belong to the family Plexauridae and are found primarily in tropical and subtropical waters. Muricea species are known for their rigid, branching structures, which provide habitat and shelter for various marine organisms. They have small polyps extending from their branches, which capture plankton and organic matter from the water.

Diet

Muricea species are suspension feeders that capture plankton and other small particles from the surrounding water.
Their polyps extend eight pinnate tentacles into the current, where nematocysts trap zooplankton and other suspended organic material.
Feeding is most effective where currents regularly deliver food to the colony.
As octocorals, Muricea species may also obtain nutrients from microscopic organisms associated with their tissues, although the importance of these associations varies among species.

Range

Muricea is an amphiamerican genus occurring in the eastern Pacific and western Atlantic.
In the eastern Pacific, the genus extends from southern California southward along the Pacific coast of Mexico and Central America to Peru, with additional species occurring around the Galápagos Islands.

Habitat

Muricea species are primarily associated with hard substrates in shallow marine environments, particularly rocky reefs, walls, ledges and other firm surfaces.
Most eastern Pacific species occur at less than 40 m depth, although some members of the genus have been recorded considerably deeper.
Colonies are generally attached firmly to rocks or reef surfaces, although some species can grow on shells, rubble or other objects resting on softer bottoms.
Different species occupy somewhat different microhabitats; some grow on exposed outer surfaces where currents are strong, while others favour protected crevices, undersides of ledges or shaded areas.

Description

Muricea species are colonial octocorals commonly known as sea fans or branching gorgonians.
Colonies range from bushy and shrub-like forms to more open, fan-shaped or candelabrum-like structures, depending on species.
The branches are supported by a flexible internal axial skeleton surrounded by living tissue containing numerous microscopic calcium-carbonate structures called sclerites.
The individual polyps are relatively small and are distributed along the branches within prominent calyces, which may be shelf-like, tubular or otherwise raised above the colony surface.
The sclerites are often strongly sculptured, with spines, tubercles or leaf-like projections, and their shapes are important for distinguishing species.
Colony colours vary among species and include white, yellow, orange, amber, red, purple and brown.