Lancelet - Revision history

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2025-02-18T17:42:52Z

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	'''~~Lancelet~~'''		{{Short description\|A primitive chordate, also known as amphioxus}}
			{{Taxobox
			\| name = Lancelet
			\| image = Branchiostoma_lanceolatum.jpg
			\| image_caption = ''Branchiostoma lanceolatum''
			\| regnum = [[Animalia]]
			\| phylum = [[Chordata]]
			\| subphylum = [[Cephalochordata]]
			\| classis = [[Leptocardii]]
			\| ordo = [[Amphioxiformes]]
			\| familia = [[Branchiostomidae]]
			\| genus = ''[[Branchiostoma]]''
			}}

	The '''~~Lancelet~~''' ~~(''Branchiostoma'')~~, also known as '''amphioxus''', is a ~~genus of~~ [[~~cephalochordate~~]]s. ~~It is a small, translucent, fish-like animal that is~~ one of the ~~closest living invertebrate relatives~~ of ~~the~~ vertebrates.		The '''lancelet''', also known as '''amphioxus''', is a small, elongated marine animal that belongs to the subphylum [[Cephalochordata]], within the phylum [[Chordata]]. Lancelets are considered to be one of the most primitive chordates, providing valuable insights into the evolutionary history of vertebrates.

	== ~~Anatomy and Physiology~~ ==		==Description==
			Lancelets are small, fish-like creatures that typically measure between 5 to 7 centimeters in length. They have a translucent, elongated body that is laterally compressed, resembling a blade or a lancet, which is how they derive their common name. The body is segmented with a series of muscle blocks called myomeres, which are visible through the skin.

	~~Lancelets have a segmented body, which is divided into head, trunk~~, ~~and tail regions. The body is covered by~~ a ~~thin, transparent skin, through which the muscles can be seen. The muscles are arranged in chevron-shaped segments, and the pattern~~ of ~~segmentation is the same as that seen in the [[vertebrates\|vertebrate~~]]s.		[[File:Branchiostoma_lanceolatum.jpg\|thumb\|left\|''Branchiostoma lanceolatum'', a common species of lancelet]]

	~~The lancelet's circulatory system is closed~~, ~~with~~ a ~~heart~~-like structure that ~~pumps~~ the ~~blood~~. ~~The blood does not carry oxygen~~, and ~~there~~ are ~~no red blood cells. Oxygen is transported around the body by simple diffusion~~.		Lancelets possess a notochord, a flexible rod-like structure that runs the length of the body, providing support. Unlike vertebrates, the notochord in lancelets persists throughout their life. They also have a dorsal nerve cord, pharyngeal slits, and a post-anal tail, which are characteristic features of chordates.

	~~The lancelet's nervous system is simple, with a nerve cord running along the back~~, ~~similar to the spinal cord~~ in ~~vertebrates, but without a true brain~~. ~~The lancelet has a simple eye spot, which can detect light~~ and ~~dark~~, and ~~a statocyst, which can detect~~ the ~~orientation of the body in relation to gravity~~.		==Habitat==
			Lancelets are found in shallow marine environments, often buried in sandy substrates. They are distributed in temperate and tropical seas worldwide. Lancelets are filter feeders, using their pharyngeal slits to capture plankton and organic particles from the water.

	== ~~Ecology and Behavior~~ ==		==Reproduction==
			Lancelets reproduce sexually, with separate male and female individuals. Fertilization is external, occurring in the water column. The larvae are planktonic and undergo metamorphosis before settling into the substrate as adults.

	Lancelets are ~~found in marine environments, usually buried in sand with only their mouth~~ and ~~gill slits exposed~~. ~~They are filter feeders, capturing food particles from~~ the ~~water with their gill slits~~.		==Evolutionary Significance==
			Lancelets are of great interest to evolutionary biologists because they are considered to be a living representation of the early chordates. Their simple body plan and primitive features provide insights into the transition from invertebrates to vertebrates. The study of lancelets helps scientists understand the development and evolution of key vertebrate features such as the notochord and dorsal nerve cord.

	~~Lancelets are hermaphrodites, with each individual having both male and female reproductive organs. They reproduce by releasing eggs and sperm into the water, where fertilization takes place.~~		==Related pages==
			* [[Chordate]]
	== ~~Evolutionary Significance~~ ==

	Lancelets are of great interest to scientists because they provide clues about the early evolution of the vertebrates. They are considered a key organism in understanding the transition from invertebrates to vertebrates.

	~~== See Also ==~~

	* [[~~Cephalochordate~~]]
	* [[Vertebrate]]		* [[Vertebrate]]
	* [[~~Evolution of vertebrates~~]]		* [[Notochord]]
			* [[Pharyngeal slit]]
	~~== References ==~~

	~~<references />~~

			[[Category:Cephalochordata]]
	[[Category:Chordates]]		[[Category:Chordates]]
	[[Category:Marine ~~fauna~~]]		[[Category:Marine animals]]
	~~[[Category:Animals described in 1834]]~~

	~~{{stub}}~~
	~~<gallery>~~
	~~File:Lancelet_Anatomy.png\|Lancelet~~
	~~File:Lancelet_GFP.png\|Lancelet~~
	~~File:Lancelet_GFP_GIF.gif\|Lancelet~~
	~~File:Amphioxus.png\|Lancelet~~
	~~File:Phylogenetic_tree_of_marsupials_derived_from_retroposon_data_(Paucituberculata).png\|Lancelet~~
	~~File:Cathaymyrus_diacodexis_(flipped).png\|Lancelet~~
	~~File:Palaeobranchiostoma_hamatotergum_(flipped).png\|Lancelet~~
	~~File:Asymmetron_lucayanum.jpg\|Lancelet~~
	~~File:1911_Britannica_-_Epigonichthys_cultellus.png\|Lancelet~~
	~~File:Branchiostoma_lanceolatum_(Amphioxus_lanceolatus).png\|Lancelet~~
	~~File:202208_Japanese_lancelet.svg\|Lancelet~~
	~~</gallery>~~

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2025-02-18T12:01:50Z

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	{{stub}}		{{stub}}
			<gallery>
			File:Lancelet_Anatomy.png\|Lancelet
			File:Lancelet_GFP.png\|Lancelet
			File:Lancelet_GFP_GIF.gif\|Lancelet
			File:Amphioxus.png\|Lancelet
			File:Phylogenetic_tree_of_marsupials_derived_from_retroposon_data_(Paucituberculata).png\|Lancelet
			File:Cathaymyrus_diacodexis_(flipped).png\|Lancelet
			File:Palaeobranchiostoma_hamatotergum_(flipped).png\|Lancelet
			File:Asymmetron_lucayanum.jpg\|Lancelet
			File:1911_Britannica_-_Epigonichthys_cultellus.png\|Lancelet
			File:Branchiostoma_lanceolatum_(Amphioxus_lanceolatus).png\|Lancelet
			File:202208_Japanese_lancelet.svg\|Lancelet
			</gallery>

Prab: CSV import

2024-02-24T11:09:32Z

CSV import

New page

'''Lancelet'''

The '''Lancelet''' (''Branchiostoma''), also known as '''amphioxus''', is a genus of [[cephalochordate]]s. It is a small, translucent, fish-like animal that is one of the closest living invertebrate relatives of the vertebrates.

== Anatomy and Physiology ==

Lancelets have a segmented body, which is divided into head, trunk, and tail regions. The body is covered by a thin, transparent skin, through which the muscles can be seen. The muscles are arranged in chevron-shaped segments, and the pattern of segmentation is the same as that seen in the [[vertebrates|vertebrate]]s.

The lancelet's circulatory system is closed, with a heart-like structure that pumps the blood. The blood does not carry oxygen, and there are no red blood cells. Oxygen is transported around the body by simple diffusion.

The lancelet's nervous system is simple, with a nerve cord running along the back, similar to the spinal cord in vertebrates, but without a true brain. The lancelet has a simple eye spot, which can detect light and dark, and a statocyst, which can detect the orientation of the body in relation to gravity.

== Ecology and Behavior ==

Lancelets are found in marine environments, usually buried in sand with only their mouth and gill slits exposed. They are filter feeders, capturing food particles from the water with their gill slits.

Lancelets are hermaphrodites, with each individual having both male and female reproductive organs. They reproduce by releasing eggs and sperm into the water, where fertilization takes place.

== Evolutionary Significance ==

Lancelets are of great interest to scientists because they provide clues about the early evolution of the vertebrates. They are considered a key organism in understanding the transition from invertebrates to vertebrates.

== See Also ==

* [[Cephalochordate]]
* [[Vertebrate]]
* [[Evolution of vertebrates]]

== References ==

<references />

[[Category:Chordates]]
[[Category:Marine fauna]]
[[Category:Animals described in 1834]]

{{stub}}

← Older revision		Revision as of 12:01, 18 February 2025
Line 36:		Line 36:

	{{stub}}		{{stub}}
			<gallery>
			File:Lancelet_Anatomy.png\|Lancelet
			File:Lancelet_GFP.png\|Lancelet
			File:Lancelet_GFP_GIF.gif\|Lancelet
			File:Amphioxus.png\|Lancelet
			File:Phylogenetic_tree_of_marsupials_derived_from_retroposon_data_(Paucituberculata).png\|Lancelet
			File:Cathaymyrus_diacodexis_(flipped).png\|Lancelet
			File:Palaeobranchiostoma_hamatotergum_(flipped).png\|Lancelet
			File:Asymmetron_lucayanum.jpg\|Lancelet
			File:1911_Britannica_-_Epigonichthys_cultellus.png\|Lancelet
			File:Branchiostoma_lanceolatum_(Amphioxus_lanceolatus).png\|Lancelet
			File:202208_Japanese_lancelet.svg\|Lancelet
			</gallery>