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tunicate
tu·ni·cate T0413200 (to͞o′nĭ-kĭt, -kāt′, tyo͞o′-)n. Any of various chordate marine animals of the subphylum Urochordata (or Tunicata), having a cylindrical or globular body enclosed in a tough outer covering and a notochord in the larval stage, and including the sea squirts and salps.adj.1. Of or relating to the tunicates.2. Anatomy Having a tunic.3. Botany Having a tunic, as the bulb of an onion. [Latin tunicātus, past participle of tunicāre, to clothe with a tunic, from tunica, tunic; see tunic.]tunicate (ˈtjuːnɪkɪt; -ˌkeɪt) n (Animals) any minute primitive marine chordate animal of the subphylum Tunicata (or Urochordata, Urochorda). The adults have a saclike unsegmented body enclosed in a cellulose-like outer covering (tunic) and only the larval forms have a notochord: includes the sea squirts. See also ascidianadj1. (Animals) of, relating to, or belonging to the subphylum Tunicata2. (Botany) (esp of a bulb) having or consisting of concentric layers of tissue[C18: from Latin tunicātus clad in a tunic]tu•ni•cate (ˈtu nɪ kɪt, -ˌkeɪt, ˈtyu-) n. 1. any marine chordate of the subphylum Tunicata (or Urochordata), having a saclike body enclosed in a thick membrane or tunic: includes ascidians and salps. adj. 2. (esp. of the Tunicata) having a tunic or covering. 3. of or pertaining to the tunicates. 4. Bot. having or consisting of a series of concentric layers, as a bulb. Also, tu′ni•cat`ed.[1615–25; < New Latin, Latin tunicātus wearing a tunic. See tunic, -ate1]tu·ni·cate (to͞o′nĭ-kĭt) Any of various primitive marine chordate animals having a rounded or cylindrical body that is enclosed in a tough outer covering. Tunicates start out life as free-swimming tadpole-like animals with a notochord (a primitive backbone), but many, such as the sea squirts, lose the notochord and most of their nervous system as adults and become fixed to rocks or other objects.ThesaurusNoun | 1. | tunicate - primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larvaurochord, urochordatechordate - any animal of the phylum Chordata having a notochord or spinal columnsubphylum Tunicata, subphylum Urochorda, subphylum Urochordata, Tunicata, Urochorda, Urochordata - tunicatesascidian - minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leavessalp, salpa - minute floating marine tunicate having a transparent body with an opening at each enddoliolum - free-swimming oceanic tunicate with a barrel-shaped transparent bodylarvacean - any member of the class Larvaceaappendicularia - free-swimming tadpole-shaped pelagic tunicate resembling larvae of other tunicates | Translationstunicate
tunicate (to͞o`nəkĭt), marine animal of the phylum ChordataChordata , phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals. ..... Click the link for more information. , which also includes the vertebrates. The adult form of most tunicates (also called urochordates) shows no resemblance to vertebrate animals, but such a resemblance is evident in the larva. The most familiar tunicates are the sea squirts, or ascidians (class Ascidiacea). Adult sea squirts are sedentary, filter-feeding, cylindrical or globular animals, usually found attached to rocks, shells, pilings, or boat bottoms. The soft body is surrounded by a thick test, or tunic, often transparent or translucent and varying in consistency from gelatinous to leathery. The tunic (for which the tunicates are named) is secreted by the body wall of the adult animal. It is composed of cellulose, an almost unique occurrence of that material in the animal kingdom. Two siphons project from the animal's body; water enters the incurrent siphon at the top of the body and leaves the excurrent siphon at the side. Food particles are filtered from the water by the pharynx, which occupies most of the body, and are then passed into the digestive system. Some species reproduce by budding, resulting in the formation of colonies of sea squirts, joined at their bases by slender stalks or embedded in a slab of common tunic material. In addition, nearly all species reproduce sexually and are hermaphroditic. The free-swimming larva, called a tadpole, has a muscular tail and is similar in appearance to a frog tadpole. The larva has the characteristic chordate features also found in the embryos of vertebrates: a dorsal, hollow nerve cord; a stiffening rod, or notochord; and gill slits leading into the pharynx. The tadpole eventually settles and undergoes a drastic metamorphosis into the adult form. A common solitary sea squirt of both coasts of North America is the slender, yellow, transparent Ciona intestinalis, about 2 in. (5 cm) tall. The sea peach, Tethyum pyriforme, is a round, peach-colored sea squirt found from Maine north. Sea grapes are clusters of the greenish colonial squirt, Molgula manhattensis, common from Massachusetts south. Golden stars are colonies of various Botryllus species; the bright yellow individual animals are grouped in starlike clusters in a flat, encrusting, greenish tunic. Asplidium species form colonies of minute animals embedded in a gristly tunic; chunks of such colonies, typically dead, bleached, and often washed ashore, are known as sea pork. There are two other groups of tunicates, both found in the plankton of open oceans. The salps (class Thaliacea) are barrel-shaped tunicates, open at both ends; they swim by muscular contractions that force water through the body. The related pyrosomes form free-floating, translucent and bioluminescent colonies known as sea pickles. The larvaceans (class Larvacea) retain the larval form, with a tail and a notochord, as adults. A commonly held theory maintains that vertebrates evolved from animals like the larvaceans. Larvaceans have no tunics, but secrete gelatinous containers, called houses; these are used to filter food from the water and are continuously discarded and replaced. Tunicates are classified in the phylum Chordata, subphylum Urochordata.tunicate
tunicate or urochordate any minute marine chordate of the subphylum Tunicata, containing the sea squirts. They feed by ciliary action and lack a NOTOCHORD, though one is present in the tail of the tadpole larva.tunicate Related to tunicate: amphioxusSynonyms for tunicatenoun primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larvaSynonymsRelated Words- chordate
- subphylum Tunicata
- subphylum Urochorda
- subphylum Urochordata
- Tunicata
- Urochorda
- Urochordata
- ascidian
- salp
- salpa
- doliolum
- larvacean
- appendicularia
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