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Branchiostoma Longirostra
''Branchiostoma'' is one of the few living genera of lancelets (order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * ''Branchiostoma africae'' Hubbs, 1927 * ''Branchiostoma arabiae'' Webb, 1957 * ''Branchiostoma bazarutense'' Gilchrist, 1923 * ''Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * '' Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Lanceolatum
''Branchiostoma lanceolatum'', the European lancelet or Mediterranean amphioxus, is a lancelet in the subphylum Cephalochordata. It is a marine invertebrate with a notochord but no backbone and is used as a model organism to study the evolutionary development of vertebrates. Anatomy ''Branchiostoma lanceolatum'' has an elongated body, flattened laterally and pointed at both ends. A stiffening rod of tightly packed cells, the notochord, extends the whole length of the body. Unlike vertebrates, the notochord persists in the adult, in form of simple dorsal neural tube slightly thickened in the anterior part (the cerebral vesicle). Above it is a nerve cord with a single frontal eye. The mouth is on the underside of the body and is surrounded by a tuft of 20 or 30 cirri or slender sensory appendages. The gut runs just below the notochord from the mouth to the anus, in front of the tail. There is a flap-like, vertical fin surrounding the pointed tail. Gas exchange takes place as w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are kept moist. The microscopic structure of a gill presents a large surface area to the external environment. Branchia (pl. branchiae) is the zoologists' name for gills (from Ancient Greek ). With the exception of some aquatic insects, the filaments and lamellae (folds) contain blood or coelomic fluid, from which gases are exchanged through the thin walls. The blood carries oxygen to other parts of the body. Carbon dioxide passes from the blood through the thin gill tissue into the water. Gills or gill-like organs, located in different parts of the body, are found in various groups of aquatic animals, including mollusks, crustaceans, insects, fish, and amphibians. Semiterrestrial marine animals such as crabs and mudskippers have gill cham ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Caribaea
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * '' Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Capense
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * '' Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Californiense
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * '' Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Bermudae
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * '' Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Bennetti
''Branchiostoma bennetti'', the mud lancelet, is a lancelet of the genus '' Branchiostoma'' endemic to the Gulf of Mexico, where it is found in the northern part. Description Like other lancelets in the genus ''Branchiostoma'', ''B. bennetti'' occurs in inshore waters where it burrows into sand or muddy sand at depths down to about . The body is laterally flattened and pointed at both ends. It has a long dorsal fin and another fin on its ventral surface, and a caudal fin at the rear end. ''B. bennetti'' differs from other western Atlantic lancelets for having the longest buccal cirri Buccal cirri are feeding structures found in the oral hood of primitive jawless organisms called amphioxus. The word buccal is derived from the term ''bucca'' which means "cheek" and cirri is derived from the Latin word ''cerrus'' meaning a tendril ... among them. These cirri are further unique in this region because of their extended lateral projections. It is presumed that these unique buccal ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Belcheri
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * '' Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Bazarutense
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * '' Branchiostoma bazarutense'' Gilchrist, 1923 * ''Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * ''B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Arabiae
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * '' Branchiostoma arabiae'' Webb, 1957 * ''Branchiostoma bazarutense'' Gilchrist, 1923 * ''Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * ''Br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiostoma Africae
''Branchiostoma'' is one of the few living genera of lancelets ( order Amphioxiformes). It is the type genus of family Branchiostomatidae. These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light. Like all lancelets, they are filter feeders that hide in the sediment most of the time. The genus inhabits coastal waters throughout the world. Species * '' Branchiostoma africae'' Hubbs, 1927 * ''Branchiostoma arabiae'' Webb, 1957 * ''Branchiostoma bazarutense'' Gilchrist, 1923 * ''Branchiostoma belcheri'' Gray, 1847 (Belcher's lancelet) * ''Branchiostoma bennetti'' Boschung & Gunter, 1966 (Mud lancelet) * ''Bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone (sedimentary rocks) through lithification. Sediments are most often transported by water (fluvial processes), but also wind (aeolian processes) and glaciers. Beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Classification Sediment can be classified based on its grain size, grain shape, and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
