Pyura stolonifera

Pyura stolonifera, commonly known in South Africa as "red bait" (or "rooiaas" in Afrikaans), is a sessile ascidian, or sea squirt, that lives in coastal waters attached to rocks or artificial structures.

It has large inhalant and exhalant siphons with slightly scalloped edges, usually set close together.

This species is found in coastal areas of the cool-temperate and warm-temperate marine bioregions of southern African, from Namibia on the west coast to south-eastern South Africa,[2] but is absent from the region's subtropical and tropical bioregions.

Despite being one of the world's most conspicuous sea squirts, Pyura stolonifera is often confused with other, morphologically similar ascidians.

[3] Pyura doppelgangera (doppelganger cunjevoi) is morphologically very similar to P. praeputialis, but is usually smaller.

Pyura stolonifera is an ecosystem engineer that can drastically alter habitats. Dense aggregates like the one shown here can dominate all substrata from the mid-intertidal to the subtidal zone, exclude other sessile species, and provide habitat for other organisms (Photo: Marc Rius)
The " Pyura stolonifera species complex"; A: Distributions of the five presently known members of this species complex; B: Phylogenetic tree showing evolutionary relationships; C-D: Intraspecific genetic structure of P. herdmani (C: ANT intron , D: mtDNA COI gene , Pyura sp. (= P. doppelgangera ) (E: ANT intron ) and P. dalbyi (F: mtDNA COI gene) (Image: Peter Teske) [ 2 ]