Sea Squirt

Molgula manhattensis

The sea squirt has a round, leathery, yellowish-green body with two short projecting siphons. It grows to no more than 2 inches.

Where does the sea squirt live?

Clumps of sea squirts can be found on pilings, jetties, oyster reefs and other hard surfaces from the shoreline to shallow waters of the middle and lower Bay.

Watch this video to see sea squirts attached to a hard surface in the Bay:

What does the sea squirt eat?

Sea squirts feed by drawing water in through their incurrent siphon.

• Food particles are filtered through the pharynx and digestive tract.
• Waste products are ejected out the excurrent siphon.

How does the sea squirt reproduce?

Sea squirts have both male and female reproductive organs. They spawn by releasing eggs and sperm into the water.

• After about three days, eggs develop into tadpole-like larvae. Sea squirt larvae are fairly sophisticated; they have long tails, a primitive eye and backbone (called a notocord), a slender nerve cord and a hollow, enlarged brain.
• The free-swimming period lasts for a short time, after which the larvae settle and attach to a hard surface with an adhesive mechanism on the head.
• In about three to four days, the tail, nerve cord and notocord are absorbed, leaving only a small mass of nerve tissue. The sea squirt's body and siphons, along with the digestive, reproductive and circulatory organs, soon develop.

Other facts about the sea squirt:

• Sea squirts are also called sea grapes, because bunches of sea squirts look like bunches of grapes.
• When prodded, sea squirts will eject a jet of water from one of their spouts.
• Sea squirts are very tolerant of polluted water.