Aquatic invasive species

EUROPEAN SEA SQUIRT

(Ascidiella aspersa)

This European tunicate was first introduced in New England in the 1980’s and can now be found in most of the Gulf of Maine. It was first detected on the south shore of Nova Scotia in 2012.

HABITAT

See the habitat of the tunicates

EUROPEAN SEA SQUIRT - DFO  B. Vercaemer
DFO B. Vercaemer

CHARATERISTICS

EUROPEAN SEA SQUIRT - MPO  B. Vercaemer
MPO B. Vercaemer
  • Body egg shaped, semi-translucent. Firm, slightly bumpy surface;
  • May reach 5 cm in length;
  • Color grayish with pinkish hue;
  • Solitary but can develop dense aggregations.

SIMILAR SPECIES

Sea grapes - DFO R. Bernier
Sea grapes
DFO R. Bernier

Sea grapes, sea potatoes and sea peaches are native solitary tunicates, but they are shaped differently and may be found individually or in small clumps. For example, sea grapes are spherical with two siphons close together at the top.

Among invasive species, European sea squirts may be mistaken for vase or clubbed tunicates but their shape, tunic surface and color are different. In addition, the European sea squirt has one siphon on top and one on the side (at approximately one third of its body length).

Sea peach - DFO  C. Nozères
Sea peach
DFO  C. Nozères

ECOLOGICAL AND ECONOMIC IMPACTS

EUROPEAN SEA SQUIRT - DFO  B. Vercaemer
DFO B. Vercaemer

WHAT YOU CAN DO