In both solitary and aggregate zooids: test thick, firm, with blunt or sharp longitudinal ridges which may be smooth or echinate.
Cylindrical (Salpa aspera, Salpa fusiformis, Salpa maxima, Salpa thompsoni, Salpa younti). Oral and atrial openings terminal. Nine body muscles on the dorsal and lateral sides of the body. Intestine coiled into a tight nucleus located posteriorly, in front of the atrial aperture. Endostyle extending far forward to the oral musculature.
Body fusiform with distinct anterior and posterior projections (Salpa aspera 1, Salpa fusiformis 1, Salpa maxima 1, Salpa thompsoni 1, Salpa younti 1). Oral and atrial openings dorsal. Six body muscles, MI to MIV and MV to MVI fused or contiguous in the mid-dorsal line, MIV to MV converging or fused laterally. Intestine coiled into a tight nucleus, located ventrally to the atrial aperture. Endostyle extending forward to the base of the anterior projection. Testis included in the nucleus. Ovary and embryo between MV and MVI, on the right side.
Seven species are recognized, 5 of which have been recorded from the Atlantic Ocean.
Salpa aspera Chamisso, 1819
Salpa fusiformis Cuvier, 1804
Salpa maxima Forskål, 1775
Salpa thompsoni (Foxton, 1961)
Salpa younti Van Soest, 1973