Figure 2 in Do Morphological Similarities and human-induced dispersal explain the non-native occurrence of Serpulidae (Annelida) in Southwest Atlantic? Taxonomic detailing is the key

Figure 2. Spirobranchus tetraceros. (A) Tube with longitudinal ridge and projection in the anterior part of the tube; (B) Complete body, lateral view. Scale bars: A-B: 2 mm.