Mussismilia

Lore & Background

Mussismilia is a genus of stony corals in the subfamily Faviinae of the family Mussidae, restricted to the Atlantic Ocean off the coasts of Brazil. Budding is always intracalicular, occurring inside the oral disc of the polyp. The corallites are phaceloid or subplocoid, with irregular teeth or one to three centres being linked. When coenosteum is present, there is a distinctive double wall. The columella is discontinuous, and the septa are porous with unique, multi-directional teeth formed of twisted threads. The columella is spongy, and the columellar teeth differ in size and shape from the septal teeth.

According to an analysis of the fossil record, Mussismilia used to be found all over the world, originating between 23 million years ago to 400,000 years ago. Currently, it only occurs along South America’s Atlantic coastline. Four species are recognized: M. hispida (the most widespread, found from Maranhão to São Paulo and on oceanic reefs), M. braziliensis (in Bahia and Abrolhos reefs), M. harttii (from Ceará to Espírito Santo, at depths of 2–6 m, with isolated records to 80 m), and M. leptophylla (along the coast of Bahia). Species differ in colony form and calice size; for example, M. braziliensis forms massive cerioid colonies, while M. harttii has a phaceloid form with larger calices.

Reader's Guide

Mussismilia corals are significant as endemic reef-builders of the Brazilian Atlantic, playing a key role in local marine ecosystems. They are mixotrophic, relying on both symbiotic dinoflagellates for photosynthesis and on captured zooplankton for heterotrophy, with their dominant feeding mode shifting seasonally. The genus is vulnerable to predation by Brazilian endemic parrotfish species, particularly Scarus trispinosus and Sparisoma amplum, which were observed preying mainly on M. braziliensis. Mussismilia species are hermaphroditic broadcast spawners, releasing gametes into the open ocean for external fertilization; research suggests that M. hispida can transmit its bacterial core to offspring via gametes. The microbiota of healthy corals includes Alphaproteobacteria, Gammaproteobacteria, Cyanobacteria, Bacteroidetes, and Firmicute, while diseased corals show a distinct shift toward Bacteroidetes and Gammaproteobacteria. As members of the family Mussidae, which are reef-building corals popular in captivity but most vulnerable to coral bleaching and climate change, Mussismilia species face environmental pressures, though some, like M. hispida, tolerate turbid and unstable environments.

Did You Know?

• Mussismilia is restricted to the Atlantic Ocean off the coasts of Brazil, though its fossil record shows it once occurred worldwide.
• The septa of Mussismilia have unique, multi-directional teeth formed of twisted threads.
• Brazilian endemic parrotfish species Scarus trispinosus and Sparisoma amplum prey mainly on M. braziliensis.