characterstics of cephalochordata?

Answer 1

cephalochordates should be examined vis a vis Hemichordates and urochordates. According to older classification these are the the three sub phyla of the phylum chordata.
The salient features of cephalochordates is the notochord that extends up to the head region.In chordates the notochord gives rise to the vertebral column and hence it should not extend up to the head region as the first neck vertebra starts from the posterior part of the skull.
Other important features of cephalochordates include the presence of circulatory system, excretory system formed by flame cells(protonephridia), presence of wheel organ, Hatschek' pits, ciliary mode of feeding, presence of atrial apertures, segmental musculature, presence of epipharyngeal groove and endostyle, ciliated pharynx. Ductless gonads.Two dorsal aortae.

Answer 2

Cool question! The phylum Chordata (Chordates) is divided into 3 sub-phyla: Cephalochordata, small fishlike animals called lancelets that have a stiff dorsal nerve cord called a notocord; Tunicata, with highly mdified gill slits but not a true backbone; and Vertebrata (Vertebrates), all animals with a backbone composed of segmented vertebrae and a central nervous spinal cord linked directly to the brain stem. Vertebrates include bony & cartilaginous fishes, with and without fully formed jaw bones (sharks, skates, rays, tuna, salmon, goldfish, catfish, eels, etc..), amphibians, reptiles, birds, mammals and humans. Note: Cephalochordates are not to be confused with CEPHALOPODS (octopuses, squid, cuttlefish and nautaluses) which belong to a completely different phylum, Mollusk.

Answer 3

My Virgo traits: basically all the good ones, not overly organized but clean and tidy most of the time except when in a negative emotional state (and this doesn't happen that often--see more on thise in next comments about negative stuff). Biggest Virgo negative I posses: if things get too melodramatic and I get confused, I tend to be overly analytical. I am fine if I don't have to re-examine my core assumptions and think I am on-coarse, but big emotional upheavals can make me spin, and then I pour over and over all the details (which I normally ignore--learned not to do this analytical thing about people/life except under extreme stress), and then I let things go and get messy too. You can tell if I am OK if everything is in order:)

Answer 4

They are also known as amphioxus or lancelets.Usually found buried in sands in shallow parts of temperate or tropical seas.
They grow to a max. size of 8 cm.
presence of nerve cord running along dorsal side.
presence of pharyngeal gill slits and a tail.
Muscles arranged in blocks called myomeres.
presence of notochord, which extends into the head.
Well tat's all i can recollect from ma zoology class !!!

Answer 5

The lancelets (subphylum Cephalochordata, traditionally known as amphioxus) are a group of primitive chordates. They are usually found buried in sand in shallow parts of temperate or tropical seas. In Asia, they are harvested commercially for food that is eaten by both humans and domesticated animals. They are an important object of study in zoology as they provide indications about the origins of the vertebrates.

Answer 6

The main feature is the presence of notochord, which is found in the cephalochordates atleast during one stage in their life cycle. Most common eg. is Amphioxus [Branchiostoma]. Other features :- fish-like without a head, have nerve chord [without a distinct brain], numerous gill slits and a post anal tail

Answer 7

marine, slender, laterally compressed, transparent, benthic (sandy)
-adults retain all four chordate characs. (chordate ancestor??)

-despite streamlined form are weak swimmers, spend most time in filter feeding position
(buried w/anterior out)

-unlike other chordates, notochord cells are muscular, allowing some contraction (adaptation
for burrowing)

-filter feeders; water over gills of pharynx, food collected on gill bars, mucus secretions
moved by cilia to intestine. Digestion intracellular by phagocytosis

-no true heart, blood propelled by contractile waves (peristaltic) in walls of major vessels.

-blood contains amoeboid cells but lack RBCs and hemoglobin
-dioecious, fertilization external

Answer 8

25 fish shaped species,living on seafloor,their common name lancelets,dorsal notochord which with muscles produses swimming motion,no brain,respiration from skin,filter feeding animals,have pharynx,and have a great evolutionary value.