Sea Squirts and Sea Pork

Class Ascidiacea

The tunicates. Who would believe that these large, fleshly blobs resembling a sponge for all practical appearances, are one of the most highly evolved of all marine invertebrates? In their adult form they are little more than a water pump, pumping water in through their vascular system, extracting nutrients and pumping the water out. It is in their larval stage that the tunicates display the characteristics which make them part of the same chordate phylum to which all fish, birds, reptiles and mammals belong.

Watch Tunicate videos on
Palagic tunicate . Tunicates on boat bottom . Star tunicate in Maine . Tunicate out of body experience

U-1800 SEA PORK, Aplidium stellatum

A large colonial ascidian found attached to rocks. Its smooth, slippery test comes in a variety of handsome colors ranging through pink, green, red and lavender. Along many parts of the Atlantic and Gulf coasts, beachcombers find these rubbery chunks of protoplasm cast upon the beach. They range from a few inches to chunks weighing 10 pounds, and produce good tadpole larvae in the spring.

Each: $22.50

U-1830 WHITE SEA PORK, Didemnum candidum

A white encrusting tunicate found on turtle grass. Test only a few millimeters thick; has small zooids. Abundant during the winter months.

Each: $22.50

U-1840 RED TUNICATE, Polyandrocarpa maxima

It is a shockingly red colonial ascidian that jumps out from the sandy benthic bottom and green sea grass meadows. It has large zooids and encrusting colonies that grow up to 6 inches in length. Size: 3-6 cm.

Each: $25.50

A tunicate (Clavelina picta)

U-1850 CLEAR SEA SQUIRT/ MANGROVE SEA SQUIRT, Clavelina picta or Ecteinascidia turbinata, as available.

Transparent solitary forms that grow in massive clusters. Internal organs can be viewed through the body wall. Gonads are large and distinctly visible; 20 or more larvae may be seen developing in the atrial cavity in summer. Available May through November. Size: 5-6 cm

Per Cluster: $25.50


sea grapes

U-1860 SEA GRAPES, Perophora viridis

They look like small green transparent berries and grow as widely separated zooids borne on creeping stolons. They may represent a link between solitary and colonial ascidians. Sea grapes are a rich source of vanadium. Size of zooid: 1-2 mm. Size of cluster: 1-2 cm.

Per Cluster: $25.50


U-1861 CLEAR SEA POTATOES, Bostrichobranchus pilularis

It lives in the sand and mud buried with only its extraordinarily long siphons sticking up. Scrape the sand grains away from their body wall, and you get a clear internal view of the viscera, and can watch the heart pumping. Individuals range from 1-3 cm. in diameter.

Per Cluster: $25.50

Sea squirt (Styela plicata)

U-1870 LEATHERY SEA SQUIRT, Styela plicata

A large solitary tunicate that grows on wharf pilings and is fertile year round. Individuals are oblong; distinct siphons have four lobes. Central individuals in a clump may be elongated due to competition. Styela can tolerate greater environmental fluctuations than most ascidians. Excellent for disection. Will vigorously expel water when handled. Size: 12-14 cm.

Per Cluster: $27.50

Red solitary sea squirt (Polycarpa aurita)

U-1871 RED SEA SQUIRT, Polycarpa aurita

A brick red solitary tunicate will catch your eye as soon as you unpack it. They can be used for filtering particulate matter out of the sea water in closed system aquaria. Size: 6-8 cm.

Each: $25.50


U-1880 SANDY SEA SQUIRT, Molgula occidentalis

The laboratory sea squirt, is the largest of all Molgula species, and is therefore more suitable for dissection. The test is thin and leathery from the sand and mud embedded in it, but the animal can be easily removed by splitting the test between the siphons. Gonads are then visible with distinct, viable, large eggs and sperm. Gravid year round. Size: 3-5 cm.

Per Cluster: $27.50

Ordering Information