Scolymia cubensis

Lore & Background

Scolymia cubensis is distributed along the coasts of Bermuda and Jamaica. In Bermuda it inhabits reefs and platforms at depths of 6 to 62 meters; in Jamaica it occurs on sandy channels between reefs and on muddy slopes near river mouths. It prefers areas where sunlight cannot reach, grows more abundantly at low latitudes on hard substrates, and is more active in warm tropical waters during the warm summer months. Its skeletal structure consists of layers of septa surrounding the core: the first layer has 6 thick septa, the second layer has 7 or more thinner septa, and subsequent layers vary in thickness as the coral grows, totaling 104 to 112 septa. The coral has rough costae covered in spines and a spongy trabecular columellae. Its polyps are non-aggressive, making it vulnerable to aggressive species, and it tends to grow more horizontally than vertically.

Reader's Guide

Scolymia cubensis reproduces sexually by broadcast spawning. It lacks a strong intraspecific immune-recognition system, allowing it to fuse with itself. After fertilization, the larva floats in open water and eventually lands on a reef deposit; if it lands close to another adult S. cubensis, the two have a high probability of fusing as the larva grows. Fusion produces a common calcareous deposit between them, resulting in di- or tri-corallites—corals made of two or three fused individuals. The subunits are genetically different due to sexual reproduction but can fuse as if they were the same individual. In Jamaica, S. cubensis engages in interspecific aggression with Scolymia lacera over light and space but is outcompeted: S. lacera kills S. cubensis tissue via an extracoelenteric feeding response, destroying and eating the tissue until the skeleton is exposed. This aggression persists even in extreme starvation or lack of sunlight. Despite this, S. cubensis is considered the 9th most aggressive coral species in Jamaica. For self-management, it settles on steep-angled reefs to dispose of sediments, using mucus strands and water currents to gather sediments to the edge of its oral disc, then undulating its mouth to shake them off, aided by gravity.

Did You Know?

• Scolymia cubensis can have 104 to 112 septa in total.
• It fuses with genetically different individuals after sexual reproduction.
• In Jamaica, it is outcompeted by Scolymia lacera via extracoelenteric feeding.
• It uses mucus strands and gravity to dispose of sediments from its oral disc.