Related FAQs: Merulinids 1, Merulinids 2, & FAQs on: Merulinid Identification, Merulinid Behavior, Merulinid Compatibility, Merulinid Selection, Merulinid Systems, Merulinid Feeding, Merulinid Disease, Merulinid Reproduction/Propagation, & Stony/True Coral, Coral System Set-Up, Coral System Lighting, Stony Coral Identification, Stony Coral Selection, Coral Placement,  Foods/Feeding/Nutrition, Disease/Health, Propagation, Growing Reef Corals,  Stony Coral Behavior, SPS Identification, SPS Behavior, SPS Compatibility, SPS Selection, SPS Systems, SPS Feeding, SPS Disease, SPS Reproduction, Related Articles: Small Polyp Stony Corals,  Stony or True Corals, Order Scleractinia, Dyed Corals, /The Best Livestock For Your Reef Aquarium:  Corals of the Family Merulinidae Part 1 Part 2: Genus Hydnophora  Part 3: Genus Merulina Part 4: To Genus Paramontastrea Part 5: Genus Pectinia

Bob Fenner

Hydnophora exesa

Family Merulinidae Verrill 1866. Five extant genera, all Pacific. All hermatypic. Readily identified by the families characteristic fused corallite wall/mounds called hydnophores. Strong septa are apparent even in open colonies.

From Wikipedia:
Taxonomy[edit]

The "robust" stony coral families of Faviidae, Merulinidae, Mussidae and Pectiniidae, have traditionally been recognised on morphological grounds but recent molecular analysis has shown that these families are polyphyletic, the similarities between the species having occurred through convergent evolution. A revised classification, proposed in 2012, places the Pacific species of Mussidae in a new family, Lobophylliidae and retains the taxon Mussidae for the Atlantic species.^[2] In the revision, the genera Echinomorpha, Echinophyllia and Oxypora were transferred from Pectiniidae to Lobophylliidae, and the genera Mycedium, Pectinia and Physophyllia were transferred to Merulinidae. The family Pectiniidae was abolished.^[3]

Aquarium Care:

Hardy once established, but easily broken, given to tissue recession at first, bleaching from lack of light. Most require strong lighting, moderate current.

Genus Astrea: /WA Corals:  massive colonies • round plocoid corallites (separate walls) • paliform lobes may be developed • septa have fine teeth • budding is extratentacular

Genus Caulastrea Dana 1846, Candy Cane Corals. From the Greek: "Kaulos" meaning Cabbage stalk and "Aster" for star. Look like a sprouting cabbage on their stick like ("phaceloid") colonial structure. /WA Corals: phaceloid colonies • small corallites 1-2 cm diameter • fine septa, occassionally exert
Formerly placed by some folks in the family Faviidae.

Caulastrea cf curvata (Milne Edwards and Haime 1849). ?COTW: Characters: Colonies are usually small. Corallites are sometimes compact, but usually sprawl irregularly. They are characteristically curved at the colony periphery and average 8 millimetres diameter. Colour: Pale brown. Similar Species: Caulastrea furcata, which can be distinguished underwater by its colour; corallites are also more regular, larger, have more numerous septa and better developed costae. Habitat: Flat substrates, often found with C. furcata. Abundance: Uncommon. Fiji pic.

Caulastrea echinulata Wijsman-Best 1972. Though septa are exsert, they're all about the same size. Small polyps, fleshy. Aquarium photo.

Caulastrea furcata Dana 1846. Small corallites (under 10 mm. in diameter). Septa are irregular, some much larger (tooth-like) than others, sticking out. Have distinctive "candy cane" appearance. Common in the wild and captivity. Easily kept, cultured, reproduced by fragmentation. Aquarium pix.

Bigger PIX: The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.

Genus Cyphastrea

Bigger PIX: The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.

Genus Echinopora (placed in the family Faviidae in the recent past.... see there as well)
Genus Echinopora Lamarck 1816. As per the name, prickly in appearance (raised corallites, spiny septa). Mostly wavy laminar sheets that appear wavy on their ends. 

Echinopora forskaliana (Milne Edwards & Haime, 1849). /COTW: Characters: Colonies are massive, with little tendency to form plates. Corallites are tall and conical, up to 10 millimetres diameter. Long and short septo-costae slightly alternate and are neatly and uniformly beaded. Paliform lobes form a neat crown. The columella has spines twisted into a spiral. Colour: Pink, sometimes brown. Similar Species: Echinopora robusta. See also E. gemmacea which has less exsert corallites and tends to form plates rather than massive colonies. Habitat: Shallow reef environments. Abundance: Common. Thank you to Joe Fish for this ID

Echinopora fructiculosa (Ehrenberg 1834). Dome shaped colonies of interlocking branches. Branches are single tubular corallites with lateral budding. Corallites 5-8 mm. Color pinkish brown w/ light colored ends. Red Sea 2019. http://www.coralsoftheworld.org/species_factsheets/species factsheetsummary/echinopora-fruticulosa/

Echinopora fructiculosa, Red Sea, Sinai pix

Echinopora lamellosa (Esper 1791). /COTW: Characters: Colonies are thin laminae arranged in whorls or tiers or, rarely, forming tubes. Stands over 5 metres across are not unusual. Corallites are relatively thin walled and small (2.5-4 mm diameter). Columellae are small and compact, and paliform lobes are well developed. Colour: Amber, pale to dark brown or greenish, often with darker brown or green calices. Similar Species: Echinopora ashmorensis, E. pacificus and E. gemmacea. Habitat: May be a dominant species in shallow water habitats with flat substrates. Abundance: Common. Taxonomic Note: A species complex. Wakatobi, S. Sulawesi, Indo. 2006

Echinopora lamellosa. E costata has larger corallites, horizontal plates, and the radiating ridges go right through corallites near the edge of the plate, rather unbelievable. I found it in Indonesia, not sure anybody else has seen it yet. The only pictures Veron has on www.coralsoftheworld.org are the ones I took. Only saw it at one dive spot, got sample, got the species named. Never seen it again but I haven't been back to Indonesia. Indonesia is a a bigger place than most people realize, because those stupid flat maps everyone likes to use (Mercator projection) hugely distort the world, making Greenland look hugeer than it is and Indonesia small. Indonesia is longest east-west,and north-south at one point it is as far as London to St. Petersburg, Russia. /Douglas Fenner via FB

Bigger PIX: The images in this table are linked to large (desktop size) copies. Click on "framed" images to go to the larger size.