A revision of the genera Salpa Forskål, 1775, Pegea Savigny, 1816, and Ritteriella Metcalf, 1919 (Tunicata, Thaliacea)

Based on material from all oceans the Salp genera Salpa, Pegea and Ritteriella are revised. Particularly the study of the number of muscle fibres has shown that Salpa maxima var. tuberculata, the subspecies Pegea confoederala bicaudata and the generally synonymized species Ritteriella retracta are valid taxa, which are given the status of species. The existence of two groups of individuals differing biometrically within the species Salpa aspera and Ritteriella retracta is reported.