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Siganus Insomnis
''Siganus insomnis'', the bronze-lined spinefoot, is a species of marine ray-finned fish, a rabbitfish belonging to the family Siganidae. It is found in the northern central Indian Ocean. It had formerly been confused with '' S. lineatus'', but was recognized as a separate species in 2014. Taxonomy ''Siganus insomnis'' was first formally described in 2014 by David J. Woodland and R. Charles Anderson with the type locality given as Addu Atoll, Feydhoo Island in the Maldives. The populations of spinefoots similr to ''Siganus lineatus'' in the waters off the Maldives, southern India and Sr Lanka had been considered to be conspecific with ''S. lineatus'' but differences in the colour and pattern as well as genetic differences showed that this was a valid, allopatric species. The specific name ''insomnis'' means "sleepless", a reference to its preference for nocturnal feeding. Description ''Siganus insomnis'' is a deep-bodied species of rabbitfish which is told apart from other rab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuticorin
Thoothukudi (formerly Tuticorin) is a port city, a municipal corporation and an industrial city in Thoothukudi district in the Indian state of Tamil Nadu. The city lies in the Coromandel Coast of Bay of Bengal. Thoothukudi is the capital and headquarters of Thoothukudi district. It is located about southwest of Chennai, northeast of Thiruvananthapuram and southeast of Bangalore. According to Confederation of Indian Industry, Thoothukudi has the second highest Human Development Index in Tamil Nadu next to Chennai. Thoothukudi City serves as the headquarters of Tamilnad Mercantile Bank Limited. Major educational establishments in the city include Government Thoothukudi Medical College, Fisheries College and Research Institute, Tamil Nadu Maritime Academy, V.O. Chidambaram College, Kamaraj College, Anna University (Thoothukudi Campus) and Government Polytechnic College. V. O. Chidambaranar Port Trust is one of the fastest growing Major Ports in India. Thoothukudi is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spearfisherman
Spearfishing is a method of fishing that involves impaling the fish with a straight pointed object such as a spear, gig or harpoon. It has been deployed in artisanal fishing throughout the world for millennia. Early civilisations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks. Modern spearfishing usually involves the use of underwater swimming gear and slingshot-like elastic powered spearguns or compressed gas powered pneumatic spearguns, which launch a tethered underwater projectile to strike the target fish. Specialised techniques and equipment have been developed for various types of aquatic environments and target fish. Spearfishing may be done using free-diving, snorkelling or scuba diving techniques, but spearfishing while using scuba equipment is illegal in some countries. The use of mechanically powered spearguns is also outlawed in some countries and jurisdictions such as New Zealand. Spearfishing uses no bait and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handline Fishing
Handline fishing, or handlining, is a fishing technique where a single fishing line is held in the hands, rather than with a fishing rod like the usual angling. It is a type of angling, and is not to be confused with handfishing, which is catching fish by hand. When handlining, one or more fishing lures or baited hooks are attached to the line, and a fishing lure and often a weight and/or a fishing float can also be attached to the line. Handlining is among the oldest forms of fishing and is still practiced throughout the world today. The fishing bait can be still fished, trolled or jigged up and down in a series of short movements. Often handling is done close to the bottom of the body of water but can also be done near or on the surface. Salt water handlining Ocean handlining is often used to catch groundfish and squid but other species are sometimes caught, including pelagic fish. Sea handlining is a good way to catch larger oceanic fish. Freshwater handlining Handlin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnet
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the order Alismatales (in the clade of monocotyledons). Seagrasses evolved from terrestrial plants which recolonised the ocean 70 to 100 million years ago. The name ''seagrass'' stems from the many species with long and narrow leaves, which grow by rhizome extension and often spread across large " meadows" resembling grassland; many species superficially resemble terrestrial grasses of the family Poaceae. Like all autotrophic plants, seagrasses photosynthesize, in the submerged photic zone, and most occur in shallow and sheltered coastal waters anchored in sand or mud bottoms. Most species undergo submarine pollination and complete their life cycle underwater. While it was previously believed this pollination was carried out without p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Algae
Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, '' Macrocystis'', a kelp of the order Laminariales, may reach in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is '' Sargassum'', which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food. Between 1,5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Algae
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (Class (biology), class), and mostly consist of multicellular, ocean, marine algae, including many notable seaweed, seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. The red algae form a distinct group characterized by having eukaryotic cells without flagella and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue-green Algae
Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue-green algae, although they are not usually scientifically classified as algae. They appear to have originated in a freshwater or terrestrial environment. Sericytochromatia, the proposed name of the paraphyletic and most basal group, is the ancestor of both the non-photosynthetic group Melainabacteria and the photosynthetic cyanobacteria, also called Oxyphotobacteria. Cyanobacteria use photosynthetic pigments, such as carotenoids, phycobilins, and various forms of chlorophyll, which absorb energy from light. Unlike heterotrophic prokaryotes, cyanobacteria have internal membranes. These are flattened sacs called thylakoids where photosynthesis is performed. Phototrophic eukaryotes such as green plants perform photosynthesis in plastids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Algae
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ( Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatoms
A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion metric tons of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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