Herdmania momus

The solitary ascidian, Herdmania momus, is among the most frequently encountered species within its class. Commonly referred to as sea squirts, this designation is somewhat ambiguous as it encompasses any member of the sub-phylum Tunicata.

Herdmania momus, also known as the red-throated ascidian, is distinguished by its vividly red siphons. The species is notable for the accumulation of iron in its tissues and the presence of small commensal shrimp residing on its gill sac. However, the distinctive coloration of most specimens is often obscured by algal overgrowth. Additionally, when found at greater depths, the red coloration may not be visible, given the absorption of lower frequencies of light by the water column.

Like all ascidians, Herdmania momus is a sessile filter feeder and is typically found attached to substrates such as rocks, at depths ranging from 3 to 50 meters (10 to 160 feet).