Sagartiogeton Blanc

Overview

Sagartiogeton undatus is an elegant sea anemone belonging to the family Sagartiidae. It is widely distributed across the northeastern Atlantic Ocean, ranging from Scandinavia southwards to the Mediterranean Sea.

Appearance

This species features a tall, cylindrical column that can reach up to 12 cm in height when fully extended. Its base is wide, firmly adherent, and can measure up to 6 cm in diameter. The oral disc is broader than the column and supports long, graceful, translucent tentacles arranged in multiples of six. These tentacles often display two fine, grayish longitudinal lines. The column itself is typically pale yellowish-buff, marked with darker brown or reddish speckles and stripes, though it lacks the suckers found in similar-looking species.

Distribution & habitat

Sagartiogeton undatus is found along the coasts of Great Britain, Ireland, and throughout western Europe. It prefers sheltered environments and is frequently encountered in sublittoral zones, often buried in mud, sand, or gravel. In these soft substrates, it attaches its base to buried stones or shells. It may also be found on hard substrates, such as rocks or within caves, and has been observed associated with Posidonia seagrass in the Mediterranean.

Biology & behavior

This anemone is a solitary, passive suspension feeder that captures small invertebrates and organic matter from the water column. While it possesses acontia—specialized stinging threads—they are not readily emitted. When contracted, the animal can become remarkably flat, measuring only a few millimeters in thickness. It is generally not found in high abundance and is sometimes mistaken for other anemone species, though it is distinguished by its lack of suckers.