Image Key > Thaliacea

• Barrel-shaped, muscular body enclosed within a gelatinous test.

• It appears in very dense swarms throughout waters of south-east Australia and is estimated to be the third most common planktonic animal in the region.
• The species has previously been reported from south-eastern Australian waters by Dakin and Colefax (1940) and Nyan Taw (1978).

• Salps are holoplanktonic tunicates.
• Circumferential muscle bands pump water in one end, across the gill surface and out the other end. This current is used for respiration, locomotion and also feeding.
• Thalia democratica has one of the fastest growth rates and shortest generation times of any metazoan animal (Heron, 1972).
• Individuals can maintain a growth rate of 10% of their length per hour for much of their life.
• Since salps feed on ephemeral phytoplankton blooms, this enables salps to colonize plankton-rich regions well before other herbivores.
• The life cycle is an obligatory alternation of sexual (hermaphroditic, gonozooid) and asexual (oozoid) generations.
• After sexual reproduction, the gonozooid carries the embryos inside the hollow body cavity (atrium).
• Each parent produces only one embryo and nourishes it via parental blood through a kind of placenta.
• On release, the asexually reproducing stage (oozoid) buds off a chain of between 20 and 80 identical embryos. These will eventually separate to become sexually reproducing forms.