Sphérocoque

Overview

Sphaerococcus coronopifolius is a perennial red alga known for its striking, arborescent appearance that often resembles a small gorgonian coral. This cartilaginous seaweed is widely recognized for its vibrant coloration, which transitions from a deep, dark red at its base to a bright, vivid carmine at the tips of its branches.

Distribution & habitat

This species is found across the Northeast Atlantic, the English Channel, the Mediterranean Sea, and the Black Sea. It typically inhabits rocky substrates in the infralittoral zone, thriving in both calm and exposed conditions. It is a sciaphilous (shade-loving) species, though it can also be observed in photophilic environments and seagrass beds.

Appearance

The alga attaches to the seafloor via a broad, discoid holdfast from which one or more cylindrical main axes arise. The thallus features irregular, abundant branching that becomes increasingly flattened and refined toward the extremities, often terminating in small, spiny branchlets. While typically bright red, specimens can sometimes display shades of orange-red or dark pink.

Biology & behavior

Sphaerococcus coronopifolius exhibits a complex life history. Its gametangial phase is the erect, bushy form commonly seen by divers, while its tetrasporophyte phase manifests as a distinct, crustose form previously known as Haematocelis fissurata. The species is known to decay slowly, making it a relatively common sight in beach drift.