Hump Coral, Porites panamensis
Hump Coral, Porites panamensis. Underwater photographs taken in Banderas Bay, Puerta Vallarta, Jalisco, July 2026. Photographs and identifications courtesy of Greg Timms, youtube.com/@CoralmasterdivesPuertoVallarta/videos. Photo Number three showing the defined boarders between individual corals. Photo Number four showing red polyps. Photo number five showing numerous bite marks.
Phylogeny: The Hump Coral, Porites panamensis (Verrill, 1866), is a hexacoral member of the Poritidae Family of colonial hermatypic (reef-building) corals. The Porites Genus is one of four genera in the Poritidae Family, and there are seventy-three recognized species in the Porites Genus. They are also known as the Emerald Coral and in Mexico as Coral Esmeralda.
Morphology: The Hump Coral is a colonial organism that is composed of thousands of individual polyps. Despite the common name, these colonies can vary in shape, including columns, flat encrustations, and even, very rarely, branching. It is commonly found growing in small individual colonies; however, it is also often seen with multiple encrusting colonies growing together on the same substrate. Unlike many other SPS (Small Polyp Stony) corals the individual colonies do not fuse together to make a larger unified colony. When several Hump Coral colonies are found at the same location they grow towards each other, but remain unattached. This may be due to the fact they are individual genders or perhaps there’s enough genetic diversity that the individual corals do not recognize each other as an identical match to allow them to fuse together, so they set up boundary lines. Hump Corals are generally green, but color is variable based on depth and light intensity. Even at the same depths they display different shades of green, some with hints of brown, some with red polyps and some with blue growth lines. The individual corallites (cups that shelter the polyps) range from 0.7 mm (0.03 inches) to 0.9 mm (0.04 inches). Hump Coral colonies can reach 13 cm (5.1 inches) in thickness and up to 50 cm (20 inches) in area.
Habitat and Distribution: Hump Corals are found primarily on rocky surfaces, but can also be found on coral rubble or reef skeletons. They live from the intertidal zone to depths up to 36 m (118 feet), though most are found in the top 20 m (66 feet) of the water column. Hump Corals are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from the west coast of the Baja Peninsula north of Magdalena Bay.
Diet: Hump Corals are a zooxanthellate coral, meaning they have a symbiotic relationship with zooxanthellae (single-cell dinoflagellates in the family Symbiodiniaceae). 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. Additionally, Hump Corals are sessile suspension feeders that use their small tentacles to capture drifting food from the water column. Their diet consists of water-borne prey like eggs, larvae and plankton.
Predation: In the more northerly latitudes, Jenner’s False Cowry Mollusk, Jenneria pustulata is a primary predator of Hump Coral polyps. Other predators include the Crown-of-Thorns, Ancanthaster planci, corallivorous fish, and for young polyps getting established, sea urchins.
Reproduction: Individual Hump Coral colonies are gonochoric (male or female for life). They reproduce sexually and asexually. Sexual reproduction is accomplished through spermcast spawning, with internal fertilization. The female broods the zygote until it becomes a planktonic planula larva, with its own zooxanthellae. The female can hold as many as three developing larvae simultaneously. These larvae measure roughly 210–350 µm. The larva has limited swimming ability and is released in to the surrounding water where it drifts until it finds a suitable habitat where it will metamorphose into a polyp. Most larvae settle near the parent colony, though they have the ability to disperse farther. The polyp will reproduce asexually, through budding, to develop a new colony. Hump Corals can also reproduce through fragmentation.
Ecosystem Interactions: Hump corals have a symbiotic relationship with zooxanthellae as described above. They are parasitized by trematodes (flatworms), which form pink nodules or cysts on the coral surface. Otherwise, the commensal, mutualistic or parasitic relationships of the Hump Coral have not been documented. They are thought to possess chemicals that prevent overgrowth by another coral.
Human Interactions: Hump Corals are collected, on a limited basis, for the aquarium trade. Their populations can be impacted locally by dredging and by increased sedimentation. Warming events, such as El Nino conditions, can cause coral bleaching. From a conservation perspective the Hump Coral is currently considered to be of Least Concern.
Synonyms: Porites californica, Porites nodulosa, and Porites porosa.