What characteristics distinguish hagfishes and lampreys from all other fishes?

Terms in this set (18) What characteristics distinguish hagfishes and lampreys from all other fishes? They are the only living fishes to lack jaws, internal ossification, scales, and paired fins.

What chordate characteristics do sea squirts and tunicates possess?

(a.k.a. tunicates or ascidians) Sea squirts belong to the phylum Chordata, which includes all animals with a spinal chord, a supporting notochord (backbone), and gill slits at one point in their lives–everything from fish to humans. Tunicates have all these features as larvae, when they resemble tadpoles.

What is clava food?

It has a variety of common names such as the stalked sea squirt, clubbed tunicate, Asian tunicate, leathery sea squirt, or rough sea squirt. … As its common names suggest, S. clava is club-shaped with an elongated oval body and a long peduncle for attaching to a substrate.

What is the difference between tunicates and sponges?

Sponges will often be soft, porous, and somewhat flexible, whereas most tunicates feel solid, firm, and gel-like (kind of like a gel-cushion you’d buy for your shoes). If you have ever accidentally stepped on a tunicate, you might have received a shot of water back, hence why they are often called “sea-squirts”.

What is the function of the tunic in a sea squirt?

Tunicates actually “wear” tunics. They secrete the leathery sac–called a tunic–that protects the animal. There are two openings in the sac, called “siphons.” Cilia on the pharynx move about to create a current and draw water in through the incurrent siphon.

What is the mode of feeding in tunicates?

Tunicates feed by straining the solid material from a current of water as it passes through a thin film of mucus lining the branchial basket.

What is the name of the one chordate feature that these tunicates retain in adulthood while the other three features seen in the larvae are lost?

The chordates are named for the notochord: a flexible, rod-shaped structure that is found in the embryonic stage of all chordates and also in the adult stage of some chordate species.

What makes a tunicate more complicated than sea sponge?

The fact is simply that it is more complicated because tunicates, unlike sponges, evolved from ancestors that had already developed differentiated cell types organized into tissues and organs and organ systems with bilateral symmetry, a complete digestive system, a central nervous system, a coelomic cavity, …

What subphylum contains the sea squirts?

sea squirt, also called ascidian, any member of the invertebrate class Ascidiacea (subphylum Urochordata, also called Tunicata), marine animals with some primitive vertebrate features.

What type of cleavage do echinoderms have?

Sea urchins undergo radial cleavage, as do “typical” deuterstomes, such as chordates, ascidians, and other echinoderms. Like embryonic cleavages in other organisms, sea urchin cleavage divisions are reductive, i.e., the cleavages result in more cells, but without an increase in the total cellular volume of the embryo.

Which subphylum includes the tunicates sea squirts?

sea squirt, also called ascidian, any member of the invertebrate class Ascidiacea (subphylum Urochordata, also called Tunicata), marine animals with some primitive vertebrate features.

Which are tunicate characteristics?

Water is filtered inside the sack-shaped body. However, many tunicates have a larva that is free-swimming and exhibits all chordate characteristics: it has a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail.

Which feature is missing from tunicates?

Water/vascular system. Tunicates do not have the well-developed secondary body cavity (coelom) of other chordates, but traces of one perhaps are represented by cavities around the heart and by an extension of the gut called the epicardium around some of the internal organs.

Which of the 4 chordate characteristics are retained in the adult tunicates?

Adult tunicates are sessile and only retain pharyngeal slits and lack a notochord, a dorsal hollow nerve cord, and a post-anal tail.

Which of the following is an example of a cephalochordate?

The example of a cephalochordate is called amphioxus which means both ends (amphi-) are sharp (-oxus). Amphioxus is a marine animal, and the several genera are distributed worldwide, especially in warm, shallow oceans where they burrow tail first into the sand and feed by filtering water.

Which of the following is not a characteristic of the phylum arthropoda?

Detailed Solution. The correct answer is Excretion takes place through metanephridia. Phylum Arthropoda is the largest phylum of Animalia which includes insects. The body of arthropods is covered by a chitinous exoskeleton.

Which phylum is the largest phylum in animal kingdom?

arthropod, (phylum Arthropoda), any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes. About 84 percent of all known species of animals are members of this phylum.

Why adult ascidians are called sea squirts?

(a.k.a. tunicates or ascidians) Sea squirts get their nickname from their tendency to “squirt” out water when they are removed from their watery home. And while they may look like rubbery blobs, they are actually very advanced animals–close to humans on an evolutionary scale. That’s because they have a spine.