What is the structure of amphioxus?
The excretory organs of Amphioxus occur as segmentally arranged structures throughout the pharyngeal region and may be divided into three components: the solenocytes, the renal tubule, and the renal glomerulus. The solenocytes possess foot processes that rest upon the coelomic surface of the ligamentum denticulatum.
What are the characteristics of amphioxus?
Amphioxus is an amazing animal and possesses a notochord, dorsal tubelike nerve cord, pharyngeal gill slits, postanal tail, and segmented somites, which are assumed to be present only in the common chordate ancestor. Its embryonic development has feature of invertebrates and vertebrates, as noted by Kowalevsky (1867).
What is Metapleural fold in amphioxus?
This anal fin bifurcates in two sheets and give place two folds to slightly stabilize them, which are known as metapleural folds. They have a series of muscular fascicles called myomeres, which are in a shape of V with the apex in a forward position.
Is amphioxus segmented?
Although the developing amphioxus CNS lacks rhombomeres and neuromeres, having only a slight anterior swelling called the cerebral vesicle, gene expression and neuroanatomy indicate that the amphioxus CNS is also segmented.
What are the classification of amphioxus?
CephalochordataLancelet / Scientific name
What phylum is amphioxus?
ChordateLancelet / Phylum
What is the common name of amphioxus?
Common lancelet
Map to
| Mnemonic i | BRALA |
|---|---|
| Scientific name i | Branchiostoma lanceolatum |
| Taxonomy navigation | › Branchiostoma Terminal (leaf) node. |
| Common name i | Common lancelet |
| Synonym i | Amphioxus lanceolatum |
What are Metapleural folds?
The metapleural folds are folds of the body wall and they contain a coelomic space, the pterygocoel (=metapleural coelom, Fig 3, 29-3C). The hepatic cecum, enclosed in a small coelomic space, may be seen in cross section beside the pharynx.
Why Branchiostoma is called lancelet?
Branchiostoma, an invertebrate chordate. In this lab, you’ll examine several different specimens of Branchiostoma, which is also called Amphioxus. This organism also goes by the common name “lancelet,” supposedly because it resembles a small lance.
What do you mean by amphioxus?
amphioxus, plural amphioxi, or amphioxuses, also called lancelet, any of certain members of the invertebrate subphylum Cephalochordata of the phylum Chordata. Amphioxi are small marine animals found widely in the coastal waters of the warmer parts of the world and less commonly in temperate waters.
What is Atrium amphioxus?
In amphioxus a big space is present, called Atrium it is lined by ectoderm. It encloses pharynx, and part of intestine. Water from pharynx enters into the atrium through gill slits. During this course respiration will take place.
Is amphioxus a genus?
Taxonomy. The first representative organism of the group to be described was Branchiostoma lanceolatum. In 1836, Yarrel renamed the genus as Amphioxus (from the Greek: “pointed on both sides”), now considered an obsolete synonym of the genus Branchiostoma.
What type of animal is amphioxus?
Amphioxus – Encyclopedia. AMPHIOXUS, or Lancelet, the name of small, fish-like, marine creatures, forming the class Cephalochorda, of the phylum Vertebrata. Lancelets are found in brackish or salt water, generally near the coast, and have been referred to several genera and many species.
What are the different genera and subgenera of amphioxus?
There are two principal genera – I. Branchiostoma Costa, having paired sexual organs (gonadic pouches); 2. Heteropleuron Kirkaldy, with unilateral gonads. Of these, the former includes two subgenera, Amphioxus (s. str.) Yarrell and Dolichorhynchus Willey.
Is amphioxus an acrania?
On account of the absence of anything in the nature of a skull, Amphioxus has been regarded as the type of a division, Acrania, in contrast with the Craniata which comprise all the higher Chordata.
What is Branchiostoma (amphioxus)?
In this lab, you’ll examine several different specimens of Branchiostoma, which is also called Amphioxus. Although the name Amphioxus is commonly used, Branchiostoma is the correct scientific name for this genus, so I’ll use that name on this page. This organism also goes by the common name “lancelet,” supposedly because it resembles a small lance.