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Squatina Guggenheim
The angular angelshark or ''Squantina guggenheim'' are sharks of the ''Squantina'' genus in the Squantinidae family. They originate in Brazil, Uruguay and Argentina while living in marine, brackish and demersal environments at depth of approximately 4-360m. Their typical food sources consist of bony fish, crustaceans, and mollusks. Morphology The ''Squantina Guggenheim'' is shaped like a ray and in males, a spiny surface is located on its pectoral fins. However, this spiny surface is absent in females and younglings. This spiny structure is thought to help hold females while mating. Typically, both males and females range 89-130cm in length. ''Squantina Guggenheim'' approximately have 18-22 teeth in the upper and lower jaw. Life Cycle The ''Squantina Guggenheim'' like some ''Chondrichthyes'' is ovoviviparous, however the females' left ovary is only functional and the embryos use the yolk as nutrition during the pregnancy. The right ovary has been found to have very little oo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomás Leandro Marini
Tomás Leandro Marini (February 27, 1902 – December 2, 1984) was an Argentine ichthyologist. Work Argentine hake (''Argentine hake, Merluccius hubbsi''), 1933 External links John Simon Guggenheim Foundation , Tomás Leandro Marini 1902 births 1984 deaths Ichthyologists University of Buenos Aires alumni University of Buenos Aires faculty 20th-century Argentine zoologists {{zoologist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal Zone
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Uruguay
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of The Western Atlantic
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
