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Opisthoteuthis Bruuni
''Opisthoteuthis bruuni'' is a species of finned cirrate octopus found along the western coast of South America. Their tissue is almost jelly-like, and they have short, round bodies. The species was originally described from 16 young specimens collected off Antofagasta, Chile, at 250 to 360 m depth. They were smaller than other known opisthoteuthids, reaching a maximum of mantle length. Even at this small, immature stage, the octopuses displayed sexual dimorphism (sex differences). The males had some enlarged suckers; three enormous suckers on each arm near the mouth were the most prominent, with a small cluster of enlarged suckers also present near the arm tips. This sort of sexual dimorphism is also found in other opisthoteuthids. Further specimens of ''O. bruuni'' have been collected from off Chile and Peru (between 5 and 33 degrees south), over a greater bathymetric range of 250 to 512 m depth. This later research also indicates a larger maximum body size (50 mm mant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrina
Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a small, internal shell and two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are associated with a unique cartilage-like shell in a shell sac. In cross-section, the fins have distinct proximal and distal regions, both of which are covered by a thin surface sheath of muscle. The suborder is named for small, cilia-like strands (cirri) on the arms of the octopus, a pair for each sucker. These are thought to play some role in feeding, perhaps by creating currents of water that help bring food closer to the beak. Cirrate octopuses are noteworthy for lacking ink sacs. Phylogeny A molecular phylogeny based on mitochondrial and nuclear DNA marker sequences by Sanchez et al., 2018, shows that the Cirrina is paraphyletic, i.e. it is not a single clade. Instead, a clade containing Opisthoteuthidae and Cirroctopodidae is siste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antofagasta
Antofagasta () is a port city in northern Chile, about north of Santiago. It is the capital of Antofagasta Province and Antofagasta Region. According to the 2015 census, the city has a population of 402,669. After the Spanish American wars of independence, Bolivia claimed Antofagasta as part of its territory. Despite having an overwhelmingly ethnic Chilean population, Chile recognised Bolivian sovereignty of Antofagasta in 1866, but in 1879 Chile recanted its recognition of Bolivian sovereignty citing a Bolivian breach of the latest boundary treaty. Antofagasta was captured by Chile in February 14 1879 triggering the War of the Pacific (1879–83). Chilean sovereignty was officially recognised by Bolivia under the terms of the 1904 Treaty of Peace and Friendship. The city of Antofagasta is closely linked to mining activity, being a port and the chief service hub for one of Chile's major mining areas. While silver and saltpeter mining have been historically importa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthis
''Opisthoteuthis'' is a genus of cirrate octopuses, sometimes known as flapjack octopuses, which are found in all the world's oceans. Behavior Like other cirrates, octopuses in Opisthoteuthis are generally small, and many dwell in the deep sea. They have cirri on their arms, internal shells to support their bodies, and muscular fins for steering. Like octopuses of Grimpoteuthis ''Grimpoteuthis'' is a genus of pelagic umbrella octopuses known as the dumbo octopuses. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film ''Dumbo'', having a prominent ear-like fin which extends from ..., opisthoteuthids have been seen resting or crawling on the seafloor. Species The following 24 species have been placed in ''Opisthoteuthis'': Notes References External links * * {{Taxonbar, from=Q3816282 Octopuses Cephalopod genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species ( freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as " rough fish" (mainly US) and "coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagic Zone
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirring up waves and setting currents in motion. The pelagic zone refers to the open, free waters away from the shore, where marine life can swim freely in any direction unhindered by topographical constraints. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grimpoteuthis
''Grimpoteuthis'' is a genus of pelagic umbrella octopuses known as the dumbo octopuses. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film ''Dumbo'', having a prominent ear-like fin which extends from the mantle above each eye. There are 17 species recognized in the genus. Prey include crustaceans, bivalves, worms and copepods. The average life span of various ''Grimpoteuthis'' species is 3 to 5 years. Species and taxonomy As noted above, many species collected on the ''Challenger'' expedition were initially classified in the genera ''Cirroteuthis'' and ''Stauroteuthis.'' Several species formerly classified as ''Grimpoteuthis'' were moved to genera ''Cirroctopus'' and ''Opisthoteuthis''. A new family, Grimpoteuthididae (alternatively spelled Grimpoteuthidae), has been proposed to accommodate ''Grimpoteuthis'' and those of genera ''Enigmatiteuthis'', '' Cryptoteuthis'', and '' Luteuthis''. The persistent confusion and disparity ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthidae
Umbrella octopuses (family Opisthoteuthidae) are a group of pelagic octopuses. Umbrella octopuses are characterized by a web of skin between the tentacles, causing them to somewhat resemble an opened umbrella when the tentacles are spread. Description Opisthoteuthidae are a group of octopuses characterized by a web of skin in between their tentacles. They have a U or W shaped shell that holds the mantle and connects to their tentacles at the bottom. This structure makes the umbrella octopus resemble an umbrella when they spread their tentacles/web out. The structure of the umbrella octopus has the oral surface below the mantle of the octopuses and the web with their tentacles surround the bottom of the mantle. Their outer skin has a very delicate consistency that results in white spots appearing on their skin when damaged. Opisthoteuthidae fall into the cirrate octopod group, meaning they have fins. Although opisthoteuthidae are categorized as cirrates, unlike the other cirrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anton Frederik Bruun
Anton Frederik Bruun (14 December 1901 – 13 December 1961) was a Danish oceanographer and ichthyologist. Educated at University of Copenhagen (1926) and employed at the Danish Commission for Marine Research (Kommissionen for Danmarks Fiskeri- og Havundersøgelser), where he participated in the third Dana expedition (1928-1930). From 1938 employed at the Zoological Museum of Copenhagen University. In 1945-46 scientific leader of the Atlantide expedition along the coast of West Africa and in 1950-1952 scientific leader of the Galathea deep-sea expedition, which circumnavigated the world. He became the first president of the Intergovernmental Oceanographic Commission, under UNESCO and was a leading figure in establishing international organisations for the exploration of the seas. The R/V ''Anton Bruun'' (former US presidential yacht ) was named after him, as was the underwater bioacoustic research facility " Station Oceanographique Anton Bruun", in Strib, Denmark ) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyologist
Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of October 2016, with approximately 250 new species described each year. Etymology The word is derived from the Greek words wikt:ἰχθύς, ἰχθύς, ''ikhthus'', meaning "fish"; and wikt:-λογία, λογία, ''logia'', meaning "to study". History The study of fish dates from the Upper Paleolithic, Upper Paleolithic Revolution (with the advent of "high culture"). The science of ichthyology was developed in several interconnecting epochs, each with various significant advancements. The study of fish receives its origins from humans' desire to feed, clothe, and equip themselves with useful implements. According to Michael Barton (professor), Michael Barton, a prominent ichthyologist and professor at Centre College, "the earliest ichthyolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopuses
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates. Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscs Of The Pacific Ocean
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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