Blastomussa wellsi

Lore & Background

Blastomussa wellsi forms small colonies composed of corallites, each with its own fleshy polyp. The mantle extends over the corallite wall, hiding the skeleton. Corallites measure 9 to 14 mm in diameter, and the septa have small blunt teeth without ordered arrangement; some septa reach the columella. The coral is brightly colored in dark red, green, grey, or blue, often with contrasting oral discs.

The soft tissues contain symbiotic zooxanthellae that provide most of its nutrition through photosynthesis. Polyps supplement this by capturing zooplankton and absorbing dissolved organic matter. This species is hermaphroditic, releasing sperm and eggs into the water for external fertilization. The resulting planula larvae drift as plankton before settling and metamorphosing into polyps, which secrete calcium carbonate skeletons and multiply by extra-tentacular budding.

Blastomussa wellsi is uncommon but widespread. Its population trend is unknown, though mature colonies are likely decreasing due to reef habitat destruction. It is also collected for the aquarium trade; Indonesia exported 3,800 live pieces in 2005. The IUCN has assessed it as near-threatened.

Reader's Guide

Blastomussa wellsi is notable for its uncertain taxonomic placement within the stony corals, as the family of the genus Blastomussa remains unresolved. Its ecological significance lies in its reliance on symbiotic zooxanthellae for primary nutrition, supplemented by zooplankton capture and dissolved organic matter absorption, illustrating a typical mixotrophic strategy among large polyp stony corals. The species' reproductive strategy—hermaphroditic broadcast spawning with planktonic larvae—is common among corals but contributes to its widespread distribution across the west and central Indo-Pacific. Its conservation status as near-threatened reflects pressures from reef habitat destruction and collection for the aquarium trade, with documented export of 3,800 live pieces from Indonesia in 2005. The unknown population trend and decreasing mature colony numbers highlight ongoing risks. The coral's bright coloration and contrasting oral discs make it visually distinctive, though the article provides no further details on its cultural or historical significance. Overall, Blastomussa wellsi represents a species whose biology and conservation challenges are documented, but whose taxonomic relationships remain an open question.

Did You Know?

• Corallites are 9 to 14 mm in diameter.
• It is hermaphroditic and releases sperm and eggs into the water for fertilization.
• Indonesia exported 3,800 live pieces of this coral in 2005.

Taxonomic Position and Genus Identity

Blastomussa wellsi belongs to the genus Blastomussa, a group classified as large polyp stony corals. This genus sits within the family Plerogyridae, placing it among a specific lineage of reef-building organisms. The large-polyp designation distinguishes these corals from smaller-polyped relatives, pointing to a morphological trait that sets them apart in the broader coral landscape. As a stony coral, Blastomussa wellsi produces a calcium carbonate skeleton, a characteristic shared across its order. The genus name and its placement in Plerogyridae reflect decades of taxonomic refinement, with species descriptions spanning from the 1940s through 2014. Wijsman-Best formally described B. wellsi in 1973, situating it within a genus that had already been receiving new species for over three decades. The family-level classification in Plerogyridae provides the broader phylogenetic context for understanding where this coral fits among its relatives, anchoring it in a well-defined branch of the stony coral tree of life.

Species Diversity and Nomenclatural History

The World Register of Marine Species recognizes six species within the genus Blastomussa, and B. wellsi occupies one of those slots. The species list reveals a nomenclatural history stretching across seven decades. The earliest described species is Blastomussa simplicitexta, named by Umbgrove in 1942, now marked with a dagger indicating extinction. Wells described B. merleti in 1961, followed by Wijsman-Best's 1973 description of B. wellsi. Head added B. loyae in 1978, and Sheppard and Sheppard contributed B. omanensis in 1991. The most recent addition is B. vivida, described by Benzoni, Arrigoni, and Hoeksema in 2014. This progression shows that the genus has been a subject of ongoing taxonomic interest, with new species still being identified in the twenty-first century. The variety of taxonomists involved, spanning multiple researchers and decades, underscores the complexity of distinguishing these large polyp stony corals from one another.

The Extinct Relative and a Vanished Lineage

Among the six recognized species of Blastomussa, one carries a particularly somber annotation: Blastomussa simplicitexta, described by Umbgrove in 1942, is marked with a dagger symbol denoting its status as extinct. This is the only species in the genus to bear that designation, making it a unique point of interest in the group's natural history. The fact that a species was described in the 1940s and has since disappeared suggests that its habitat or population was lost in the intervening decades. The remaining five species, including B. wellsi, B. loyae, B. merleti, B. omanensis, and B. vivida, are all extant, continuing to represent the genus in living reef ecosystems. The extinction of B. simplicitexta serves as a reminder that even within a small genus of large polyp stony corals, individual lineages can vanish entirely, leaving behind only the taxonomic record and the memory of those who first described them.

Presence in the Reef Aquarium Hobby

While Blastomussa wellsi is primarily a marine organism of ecological significance, members of the genus have found a secondary audience in the world of reef aquariums. The fact that Blastomussa species are sometimes found in captive reef setups indicates that hobbyists and aquarists have taken an interest in keeping these large polyp stony corals outside their natural habitat. This is not a universal practice; the qualifier suggests that keeping these corals is not routine or widespread, perhaps due to specific care requirements or the difficulty of sourcing them ethically. The genus's placement in the family Plerogyridae and its identity as a stony coral with large polyps likely contribute to its visual appeal for aquarists seeking to replicate reef environments. The ReefCorner database, which maintains an entry for B. merleti, provides a resource for those in the hobby seeking information about the genus, further linking the taxonomic world to the practical world of aquarium keeping.