(Forskål, 1775)
Description
— Aggregate form with a loose flabby test. No posterior projections or protuberances. M1-M2 and M3-M4 touch (cold water animals) or fuse (warm waters) mid-dorsally, each muscle pair forming a cross. The muscle bands are short because they are interrupted before they reach the mid-lateral region. Stomach spherical (concentrated in a ball or nucleus).
— Solitary form with pear-shaped test, smaller posteriorly. M1-M2 and M3-M4 touch or fuse, each pair forming a cross. The gut is compact and closely encircled by the stolon.
Size
Length of aggregate form up to 150 mm; length of solitary form up to 120 mm.
Depth range
Epipelagic, living near the surface.
Distribution in the North Sea
Northern North Sea, very rare.
World distribution
Cosmopolitan, eurythermic species, occurring between ca. 60°N and 45°S. One of the more common salpid species.
Remark
The number of muscle fibers in M1-M4 in both the aggregate and solitary zooids shows clinal variation, decreasing from higher to lower latitudes, in other words, from colder to warmer waters (Van Soest, 1974; Van Soest, 1975b).