Meandrinidae Family of Flower Corals

Two Flower Coral of the Meandrinidae Family can be found in this website:

Phylogeny: Flower Corals of the Meandrinidae Family are, like hydroids, jellyfish and sea anemones, members of the phylum Cnidaria. They are in the subphylum Anthozoa, the class Hexacoralia, and the order Scleractinia of stony corals. The Meandrinidae Family is one of twenty four families in the suborder Vacatina.  The Meandrinidae Family is small, with only four genera and six species. The name Meandrinidae comes from the Greek word meaning “meandering”, referring to the wandering valleys between the polyps of some species in this family (maze corals). Species in the Meandrinidae Family are also known as Meandrinids.

Morphology: Flower Corals have radial symmetry, a hollow digestive cavity, and specialized stinging structures contained within the tentacles surrounding the mouth. Their polyps have a flower-like appearance, representative of the subphylum Anthozoa. As hexacorals, they have six-fold symmetry.  In addition, their polyps produce a hard, calcareous skeleton, representative of the order Scleractina. They live in colonies where new generations build upon the skeletons of previous generations, forming coral reefs. Flower Corals may grow as massive or encrusting corals. The individual corallites are usually well-spaced. The corallites are solid with non-porous walls and evenly spaced septa. Massive species can grow as columns, shelves, domes,  hemispherical heads, or be phaceloid (individual corallite tubes joined at the base). Corals in this family tend to be gray, brown, yellow, or green in color. While some colonies of Meandrids will measure only 10 cm (3.9 inches) or so, some domes can exceed 1,0 m (3 feet 3 inches) in diameter and some columns more than 3.0 m (10 feet) in height.

Habitat and Distribution: Flower Corals grow on hard substrates at depths from 1 m (3 feet) to 80 m (260 feet).  They are found in subtropical to tropical waters of the Western Atlantic. Five species from the Meandrinidae Family are found along the east coast of Mexico.

Reproduction: Flower Coral colonies are gonochoric (male or female for life), that reproduce via broadcast spawning. The resulting gametes undergo several stages of development until they grow into a settled coral.  In addition, reproduction can occur asexually through fragmentation or budding.

Ecosystem Roles:  Flower Corals have a symbiotic relationship with zooxanthellae, single-cell dinoflagellates. Zooxanthellae live within certain coral polyps, sea anemones, jellyfish, and nudibranchs. They produce energy by means of photosynthesis and the energy is passed along to their hosts, sometimes providing the majority of the host’s total energy needs. In return, the host provides nutrients, carbon dioxide, and a secure, sunlit, platform for the zooxanthellae. During periods of chemical or thermal stress the corals can eject the zooxanthellae to reduce metabolic stress. This causes the coral to appear white. This process is known as coral bleaching. The coral will replace the zooxanthellae after the stress is resolved, or it will acquire a different species of zooxanthellae that is better accommodated to the new environment. In either case, the polyp risks starvation if it is unable to replace the zooxanthellae quickly. Flower Corals supplement the energy provided by zooxanthellae by using their tentacles to capture amphipods, other plankton, and suspended organic matter from the surrounding water. The tentacles then pass the food to the mouth. Flower Corals are preyed upon by crabs, fish, gastropods, sea stars, and polychaete worms.