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Related to Ascidians: Urochordata, Bryozoans, Tunicates


[From New Latin Ascidia, genus name, from Greek askidion, diminutive of askos, wineskin.]


1. (Zoology) any minute marine invertebrate animal of the class Ascidiacea, such as the sea squirt, the adults of which are degenerate and sedentary: subphylum Tunicata (tunicates)
2. (Zoology) ascidian tadpole the free-swimming larva of an ascidian, having a tadpole-like tail containing the notochord and nerve cord
(Zoology) of, relating to, or belonging to the Ascidiacea


(əˈsɪd i ən)

1. any tunicate of the class Ascidiacea, having in the larval stage a notochord, a characteristic of the embryonic vertebrate.
2. belonging or pertaining to the class Ascidiacea.
[1855–60; < New Latin Ascidi(um) a tunicate genus < Greek askídion a small bag + -an1]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.ascidian - minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leavesascidian - minute sedentary marine invertebrate having a saclike body with siphons through which water enters and leaves
tunicate, urochord, urochordate - primitive marine animal having a saclike unsegmented body and a urochord that is conspicuous in the larva
Ascidiaceae, class Ascidiaceae - sometimes classified as an order: sea squirts
sea squirt - ascidian that can contract its body and eject streams of water
References in periodicals archive ?
In the sea and along its shores swarm organisms of the other living world -- marine diatoms, crustaceans, ascidians, sea hares, priapulids, coral, loriciferans and on through the still mostly unfilled encyclopedia of life.
In particular, colonial ascidians can undergo WBR as a result of their high blastogenetic potential (Oka and Watanabe, 1957, 1959; Milkman, 1967; Zaniolo et al.
Increasing accumulation of biofouling organisms such as ascidians within aquaculture sites is a growing problem (Adams et al.
2005) Specification of embryonic axis and mosaic development in ascidians.
However, in ascidians high concentrations of carbohydrate can be explained by the presence of a protective coat, characteristic of tunicates, composed of tunicin, a substance similar to cellulose (EOL, 2013).
35) Besides bacteria and diatoms, other species like barnacles, serpulidae, ascidians, bryozoans, algae, and polychaetes are the frequent fouling organisms encountered on hard substrates in Mar del Plata harbor.
Chemical control of bacterial epibiosis on ascidians.
I used a PowerPoint presentation with photographs of algae, protozoa (single celled organisms - star forams are found on Lord Howe), sponges, cnidaria (sea jellies, sea anemones, coral, bryozoans), Molluscs (sea snails and sea slugs, clams, cuttlefish), Echinoderms (sea stars, sea urchins, brittle stars, feather stars, basket stars), Arthropods (hermit crabs, coral banded shrimp, anemone shrimp, painted crayfish), Chordates including those without backbones - Ascidians (yes there is such a thing), and those with back bones - Sharks and Rays, Fish, Turtles, Birds and Mammals (Lord Howe has Dolphins and gets the odd Whale shark or other whales passing by).
Some specific topics covered include regeneration of coexisting introduced versus native species of pine in the Canary Islands, invasive ascidians in waterways, field-level hyperspectral measurements for identifying wetland invasive plant species, gear for eradication of swimming crabs, and invasiveness of warm-season pasture legumes in the Southeastern US.