Branching Black Coral

Overview

Antipathes dichotoma, commonly known as the branching black coral, is a colonial cnidarian characterized by its dark, rigid skeleton. It serves as the type species for the genus Antipathes and is primarily recognized for its distinct, sparsely branching structure.

Appearance

This coral forms colonies that can reach over one meter in height, featuring slender, flexible branches that typically project at angles of 70 to 90 degrees. While the living tissue covering the colony is often white, yellow, or orange, the underlying calcareous skeleton is characteristically black. The branches are covered in small, smooth, conical spines arranged in four to six longitudinal rows. Its polyps, which possess six tentacles, are generally 2 to 2.4 mm in diameter and are distributed in a single series on smaller branchlets, becoming more densely packed on the main stem.

Distribution & habitat

Antipathes dichotoma is primarily found in the eastern Atlantic Ocean and the Mediterranean Sea, with documented occurrences in the Tyrrhenian Sea, the Bay of Naples, the Bay of Biscay, and off the coast of Morocco. It typically inhabits deep-water environments, ranging from shelf depths to the upper bathyal zone, often favoring rocky substrates in dimly lit or dark conditions.

Feeding

As a passive filter feeder, this coral relies on water currents to bring planktonic prey within reach. It captures these organisms using its polyps, which extend their tentacles to trap food particles from the surrounding water column.

Biology & behavior

These corals are known to host various symbiotic invertebrates, including small crustaceans and gobies. Reproduction is typically gonochoric, where colonies produce either male or female gametes that are released into the water for external fertilization, eventually resulting in planktonic larvae that settle on suitable substrates.