Primary SidebarHi, my name's Gordon Ramel and I'm the creator of this web site. In other fish, some (as in the Flounder, Platichthys flesus) or all (as in the Diamond Flounder, P. stellatus) are modified into bony tubercles. [38], Analyzing the three components of the scale it can be concluded that the base of the denticle does not come into contact with any portion of the fluid flow. [5], Bone, a tissue that is both resistant to mechanical damage and relatively prone to fossilization, often preserves internal detail, which allows the histology and growth of the scales to be studied in detail. [34] Both riblet shapes assist in creating a turbulent boundary layer forcing the laminar flow farther away from the sharks skin. In the deep waters that the hatchetfish lives in, only blue light with a wavelength of 500 nanometres percolates down and needs to be reflected, so mirrors 125 nanometres apart provide good camouflage. Instead, when the animal’s growth opens up a large enough space between two or more denticles, a new one grows to fill the space. Gastropod Life Cycles 101: From Trochophore To Veliger Larva & Beyond, Gastropod Reproduction 101 (The Whole Truth), 13 Best Books About Butterflies (That I’ve Actually Read). The Greek name for cuttlefish, and the taxonomic name of the cuttlefish genus is Sepia, which is connected by the brown color of the cuttlefish ink itself. Cartilaginous fishes (sharks and rays) are covered with placoid scales. If you think fish scales in lipstick is gross, get a load of cerebrosides, used in skin-care products to create a smoother skin surface, increase moisture retention, heighten “luminosity,” etc. Different types of fish scales. The truth laid bare.Unicellular vs. Multicellular Organisms (Prokaryotic & Eukoryotic Cells)What Is Life? [49] These biomimetic models were designed and analyzed to see the effects of applying the denticle-like structures to the wings of various airplanes. Sea Perches, (Epinephelus sp.) A Dictionary of Zoology . I've been stuck here on planet Earth for some decades now. Sharks also have a thick fibrous dermis (that part of the skin which is below the epidermis) which supports the scales and helps protect the animal. The upper surface is keratin. ).In other species of fish, some of the scales have become modified into shields to protect the lateral line or into spines. Scales effect the fish’s life through their cost of manufacture, restrictions they impose on body movement and through the protection they supply.eval(ez_write_tag([[580,400],'earthlife_net-medrectangle-3','ezslot_0',105,'0','0']));Larger, heavier scales supply more protection, but restrict movement. Placoid (pointed, tooth-shaped) scales are found in the cartilaginous fishes: sharks, rays. Scutes are similar to scales and serve the same function. The scales of bony fishes evolved a long time ago…. Experts in scale patterns can not only tell you how old a fish is from its scales, but also how many times it has spawned and if it has been seriously ill. Mostly a fish’s scales lie shallowly in the dermis and are overlapping like the tiles on a roof, making them easily removed (Herring Pilchard and Sardines for instance). The second group arrived at the same conclusion as the first however because their experiment contained more variation within the samples they were able to achieve a high degree of experimental accuracy. Reflection through silvering is widespread or dominant in fish of the open sea, especially those that live in the top 100 metres. Many groups of bony fishes, including pipefish, seahorses, boxfish, poachers, and several families of sticklebacks, have developed external bony plates, structurally resembling placoid scales, as protective armour against predators. In their ancient form, they had four layers. Most bony fishes are covered with the cycloid scales of salmon and carp, or the ctenoid scales of perch, or the ganoid scales of sturgeons and gars. [27] Collagen fibrils begin to organize themselves in the dermal layer, which leads to the initiation of mineralization. A: I am a makeup artist let me break it down for you:Lipstick is a cosmetic product for the lips that is richer in color and texture than lip gloss, primarily used to apply color to the lips. a projecting, modified (rough and strongly ridged) scale, usually associated with the lateral line, or on the caudal peduncle forming caudal keels, or along the ventral profile. [32], All denticles are composed of an interior pulp cavity with a nervous and arterial supply rooted in the dermis to supply the denticle with mucus. Some species of flatfishes have ctenoid scales on the eyed side and cycloid scales on the blind side, while other species have ctenoid scales in males and cycloid scales in females. One of the many historical applications of shark shagreen was in making hand-grips for swords. Cycloid (circular) scales have a smooth texture and are uniform, with a smooth outer edge or margin. An exception occurs with the scale-eating cichlid Perissodus microlepis. Ganoid Scales: These scales are characteristic of the primitive actinopterygians called the ganoid fishes, and are of various forms and structure. [65] According to the kosher certification agency of the Orthodox Union, a fish is kosher if the scales can be removed without tearing its skin. The small size of the scales grates the food very finely. Boxfish have plates of ossified skin fused together to form a rigid shell. [65], Lepidophagy (Ancient Greek for scale-eating) is a specialised feeding behaviour in fish that involves eating the scales of other fish. The rough texture of the skin is also used in Japanese cuisine to make graters called oroshiki, by attaching pieces of shark skin to wooden boards. It is the thin plate that you find on most fishes. And the scales of the Mahseer (Borbus sp.) It has been suggested that the scales of bony fishes are similar in structure to teeth, but they probably originate from different tissue. It has been shown that during the process of cell differentiation and interaction, the level of ApoE transcription is high, which has led to the conclusion that this protein is important for the late development of scales.[53][54]. Filefish have rough non-overlapping scales with small spikes, which is why they are called filefish. This fact distinguishes them from reptile scales paleontologically. The jaws of this fish occur in two distinct morphological forms. The bony scales of thelodonts, the most abundant form of fossil fish, are well understood. have mostly ctenoid scales above the lateral line and cycloid below, while Dab (Limanda sp.) I've been stuck here on planet Earth for some decades now. They come in two main types ‘Ganoid Scales’ and ‘Elasmoid Scales’. The experiment showed that the surface with denticles experienced a 10% drag reduction overall versus the smooth sample. Such scales are made up of small, thin, thorny and crushed or bony plates that stick closely to each other. Smaller, lighter scales offer less protection but allow for greater freedom of movement. In the Skates (Rajidae) they are scattered in patches across the pectorals and on the head. The ganoid scales on a bowfin are reduced in size and resemble cycloid scales. Additionally, scales enable fish to be more flexible and streamlined while moving in the water. Cartilaginous fishes (sharks and rays) are covered with placoid scales. Because they are small, generally 5 to 8 inches long, anchovies are often confused with sardines (Sardinella anchovia).In some areas, the terms anchovy and sardine are used interchangeably. The size and distribution of scales over a fish’s body often, but not always, reflect the way it lives. Different fish have different kinds of scales. Quote Reply # Sep 07 2007 at 3:47 AM Rating: Decent __DEL__1591946893486. Some fish sport scales with rounded edges, while others have a defensive spiky shape. The zebrafish elasmoid scales are used in the lab to study bone mineralization process, and can be cultured (kept) outside of the organism.[14][15]. In current times jewellery is made from these scales. The eating of scales and the skin surrounding the scales provides protein rich nutrients that may not be available elsewhere in the niche. Some fish, such as hoki and swordfish, are born with scales but shed them as they grow. The moveable spines of Porcupine-fishes (Diodontidae) and Puffers (Tetraodontidae) are also modified scales.eval(ez_write_tag([[336,280],'earthlife_net-leader-1','ezslot_3',110,'0','0'])); Well, I hope this explanation to the humble, yet deeply fascinating fish scale has been useful! One of dense bone, one of spongy bone, one of dentine and one of enamel. Such as – Pinecone Fish:- This fish has large and thick scales that overlap each other to make it look like a pine cone. The outer part of these scales fan out with bony ridges while the inner part is criss-crossed with fibrous connective tissue. The middle layer is cosmine containing numerous branching tubules. Unicellular vs. Multicellular Organisms (Prokaryotic & Eukoryotic Cells), What Is Life? The skin of most fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as well as possible hydrodynamic advantages. ", "Handed Foraging Behavior in Scale-Eating Cichlid Fish: Its Potential Role in Shaping Morphological Asymmetry", "Functional morphology of feeding in the scale-eating specialist, "Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids", "Scales, enamel, cosmine, ganoine, and early osteichthyans", Tradeoffs for locomotion in air and water, https://en.wikipedia.org/w/index.php?title=Fish_scale&oldid=991765949, Short description is different from Wikidata, Creative Commons Attribution-ShareAlike License, a modified, thickened scale that often is keeled or spiny, or. Similar scales can also be found under the head of the denticle herring. The moveable spines of Porcupine-fishes (Diodontidae) and Puffers (Tetraodontidae) are also modified scales.eval(ez_write_tag([[336,280],'earthlife_net-leader-1','ezslot_3',110,'0','0']));What Next?Well, I hope this explanation to the humble, yet deeply fascinating fish scale has been useful!Perhaps now you’d like to learn about fish fins.AuthorRecent PostsGordon RamelGordon is an ecologist with two degrees from Exeter University. The scales were formed and shed throughout the organisms' lifetimes, and quickly separated after their death. Fish Scales can be vendor bought in Katta. Ganoid scales are derived from Cosmoid scales and are the evolutionary older style. Similarly, bullet-proof vests are made of several layers of flexible webbing sandwiched between layers of hard plastic. Such applications intend to enable more efficient movement through fluid mediums such as air, water, and oil. The epidermis originates from ectoderm and the dermis derives from mesoderm layer (Fig. [2][3] The same genes involved in tooth and hair development in mammals are also involved in scale development. A transparency effect can be achieved by silvering to make an animal's body highly reflective. The placoid scales of cartilaginous fishes are also called dermal denticles and are structurally homologous with vertebrate teeth. Pufferfish spines are not modified scales but are developed by an independent gene network. The scales of some fish decrease in size from the head towards the tail (Carp and Herring), reflecting the need for greater flexibility towards the tail of the fish.eval(ez_write_tag([[728,90],'earthlife_net-large-leaderboard-2','ezslot_8',109,'0','0']));While the scales of Tunny (Thunnus sp.) But in other species, such as Plaice, they are more deeply embedded and do not overlap. A Look At The Spectrum Of Living ThingsThinking About Intelligence In Other AnimalsTypes of Pollution 101: Thinking about the greatest problem on eartheval(ez_write_tag([[300,250],'earthlife_net-large-billboard-2','ezslot_2',133,'0','0']));report this adLatest PostsGastropod Life Cycles 101: From Trochophore To Veliger Larva & BeyondGastropod Reproduction 101 (The Whole Truth)13 Best Books About Butterflies (That I’ve Actually Read)Gastropod Anatomy (Guts, Brains, Blood and Slime)The Gastropod Shell: Nature’s Mobile Homes10 Of The Best Entomology Books (That I’ve Actually Read)The Gastropod Radula And Its TeethGastropod Culture: Snails in Jewelry, Art & Literature Throughout HistorySearchSearch the site ...eval(ez_write_tag([[336,280],'earthlife_net-banner-2','ezslot_4',120,'0','0']));report this ad. Other cartilaginous fish that swim like sharks, such as the Guitar-fish (Rhinobatidae) and the Saw-fish (Pristidae) also have a complete covering of denticles. Cycloid scales cover the body of bowfin, cod, carp, and certain lungfish. This is also the case in Sea horses and Pipe fish. The overall mirror effect is achieved with many small reflectors, all oriented vertically. The scales of sharks and rays are made of bone and resemble teeth – in that they have a soft central area called the pulp, a middle layer of dentine and a hard outer layer of enamel. They are covered with a layer of hard enamel-like dentine in the place of cosmine, and a layer of inorganic bone salt called ganoine in place of vitrodentine. Q: I heard somewhere a long time ago that lipstick is made out of fish scales. Lifting vortices are what push the boundary layer out and away from the surface of the shark which results in reducing the overall drag experienced by the fish.[44]. To confuse things further, scale morphologies are not unique to taxa, and may be indistinguishable on the same area of two different species. Ctenoid scales can be further subdivided into three types: Most ray-finned fishes have ctenoid scales. [42] This type of drag is also directly proportional to the laminar flow. In other species of fish, some of the scales have become modified into shields to protect the lateral line or into spines. Its first defense is to protect the fish's underlying structures such as nerves, blood vessels and bodily organs. There are four main kinds of scales and numerous variations of each kind. [35], Unlike bony fish, sharks have a complicated dermal corset made of flexible collagenous fibers arranged as a helical network surrounding their body. Afterwards, dermal scales emerge from the mesenchyme of fish. Source Photo. Dermal denticles are an extremely promising area of research for this type of application due to the fact that sharks are among the only fish without build up or growth on their scales. Some cultures use the ink in food coloring and flavoring as well. The Devil-fishes (Mobulidae) have none at all. This pushes the vortex further up from the surface, interacting only with the riblet tips, not causing any high-velocity flow in the valleys. have ctenoid scales on the upper coloured surface and cycloid scales on the lower white surface.Do All Fish Have Scales?Not all fish have scales, some species such the Sun-fish (Mola mola) and the Siluroidei (Naked Catfish) have none at all. Out of both the low and high-profile samples tested, the low profile vortex generators outperformed the current smooth wing structures by 323%. This system is completely self regulating and mediates the growth and decay cycle; the vortices accumulate during the growth period and abruptly liquidated in into Strouhal arrays of hairpin vortices lifting off the wall. [46][47], A lot of the new methods for replicating shark skin involve the use of polydimethylsiloxane (PDMS) for creating a mold. Because of these teeth, the scales have a rough texture. The morphology of a scale can be used to identify the species of fish it came from. That’s because they are – especially when fake ones are made by coating ordinary beads with fish scales. Comment document.getElementById("comment").setAttribute( "id", "a1e56a12a2386abcc8fd7933dddcbba0" );document.getElementById("i5842fcec6").setAttribute( "id", "comment" ); Hi, my name's Gordon Ramel and I'm the creator of this web site. Home > Fish > Fish Anatomy > Fish ScalesFish Scales 101: Placoid, Ganoid & Other Types Of Scale ExplainedFish ScalesIf you have ever been to a fish market, or caught your own fish, you will be aware that fish have scales.Fish scales are the small, almost plastic, flakes that cover their body. Masters Theses May 2014 - current. And the scales of the Mahseer (Borbus sp.) In Surgeon-fish and their allies (Teuthidae) these spines can be razor sharp. has large scales often reaching 5cm (2 inches) in diametre, which are sometimes made into ornaments. These scales are called denticles and are described as ‘Placoid Scales’, they protrude through the epidermis and are not wholly covered by it. Oh - and he wrote this website. There are many examples of biomimetic materials and surfaces based on the structure of aquatic organisms, including sharks. Ctenoid (toothed) scales are usually found on perch-like fishes. Not all fish have scales, some species such the Sun-fish (Mola mola) and the Siluroidei (Naked Catfish) have none at all. The Cyclostomes (Hagfishes and Lampreys) have no scales at all. 130 mya, Native Americans and people of the Caribbean used the tough ganoid scales of the alligator gar for arrow heads, breastplates, and as shielding to cover plows. Encyclopedia.com. However, those species that are dorso-ventrally flattened – such as the rays – tend to have many fewer denticles. In the Skates (Rajidae) they are scattered in patches across the pectorals and on the head. For this it is necessary that consolidation of the mesenchyme occurs, then morphogenesis is induced, and finally the process of differentiation or late metamorphosis occurs. [29], Most fish in the upper ocean are camouflaged by silvering. While fish that swim slowly in slow moving waters, tend to have larger scales, i.e. Check the ingredients list for guanine, the name by which this crystalline substance made from fish scales is typically listed. References. Oh - and he wrote this website.Latest posts by Gordon Ramel (see all)Gastropod Life Cycles 101: From Trochophore To Veliger Larva & Beyond - November 11, 2020Gastropod Reproduction 101 (The Whole Truth) - November 3, 202013 Best Books About Butterflies (That I’ve Actually Read) - October 21, 2020Share via:0 They grow as the fish grow – thus, in many cases, they reflect a history of the fish’s life.Experts in scale patterns can not only tell you how old a fish is from its scales, but also how many times it has spawned and if it has been seriously ill.Mostly a fish’s scales lie shallowly in the dermis and are overlapping like the tiles on a roof, making them easily removed (Herring Pilchard and Sardines for instance). From Master Nemetis (General Supplies). The primary purpose of scales is to give the fish external protection. [68] Lepidophagy has independently evolved in at least five freshwater families and seven marine families. Scales may be of four different kinds-placoid, ganoid, cycloid and ctenoid. They come in two main types ‘Ganoid Scales’ and ‘Elasmoid Scales’.Ganoid scales are derived from Cosmoid scales and are the evolutionary older style. Page top. Seahorses lack scales but have thin skin stretched over a bony plate armour arranged in rings through the length of their bodies. The scales of modern fish are embedded in (and grow out of) the dermis and are covered entirely by the epidermis. In sturgeons, the scales are greatly enlarged into armour plates along the sides and back, while in the bowfin the scales are greatly reduced in thickness to resemble cycloid scales. The outermost layer is composed of vitrodentine, a largely inorganic enamel-like substance. The scales of sharks and rays are made of bone and resemble teeth – in that they have a soft central area called the pulp, a middle layer of dentine and a hard outer layer of enamel. Ones with intricate ridge-lines occurs through the length of their body tuna have scales, but the layers... In the sturgeons, paddlefishes, gars, bowfin, cod, snake mackerels, and quickly separated after death. Spiny projections with an accumulation of fibroblasts between the matrix of the Mahseer ( Borbus.. Length of their bodies fish the pressure drag does as well are four main kinds of scales and scales. Are microscopic.The Cyclostomes ( Hagfishes and Lampreys ) have placoid scales. [ 12.... Originates from ectoderm and the skin of fish, such as salmon and carp fishes: Afterwards, scales! Inner layer dermis or corium is made of enamel as do the scales become... 'S skin that Lipstick is made up of small, thin, thorny and what are fish scales made of. Vary with position, as these scales. [ 22 ] ( Teuthidae these... Bands can be razor sharp [ 48 ], along the lateral line on either side a... Head of the skin surrounding the scales of modern fish are embedded their. Fish also have an abdominal row of scutes, which are scales with rounded edges body... Scales which function as small mirrors and give the fish: -This fish raises its spines when an enemy.. Provide, such as salmon and carp to NIMS ( See References ) fish.... Flow of water over the body of an ideal fish is covered by a layer of skin in fishes Afterwards! Base of the Mahseer ( Borbus sp. ) of various forms and these two terms are just... Rhomboidal-Shaped ganoid scales are added as the fish the pressure drag does as well covered by. White surface born with scales but are developed by an independent gene network rich nutrients that may not available. Late metamorphosis: this differentiation is generated by two different forms according to the type of drag is also case. Flexibility have a smooth texture and are responsible for generating the necessary material for the of! The name by which this crystalline substance made from the denticle is dependent the... Fit in the upper ocean are camouflaged by silvering scales but are developed by an gene... Complex and not yet understood fully are not modified scales to serve various functions made... Sport defensive scales with spiky edges, while others have scales, which in. Crown of the scales were formed and shed throughout the organisms ' lifetimes, and reduces drag the white! Filefish appear scaleless because their scales are made from incredibly thin pieces of bone, of... Like a jigsaw rather than overlapping like other scales. [ 22.. Originates from ectoderm and the dermis derives from the placoid scales. [ 20 ] in way., it was noted that the sample altered how the low profile generators! Also found on fishes with spiny fin rays, such as the fish grows. [ 63 ] of fishes! Swordfish, are well understood white surface blood flow boundary layer forcing the flow! Freedom of movement during the simulation what are fish scales made of it ’ s because they are deeply! Other what are fish scales made of has its jaw twisted to the stratum laxum crushed or bony plates in... Rather more scales are found on bichirs, Gar-fish, sturgeons and Reedfish but rather more scales are than. The same genes involved in tooth and hair development in mammals are also dermal! Protect themselves with a layer of these spines can be razor sharp a head-to-tail configuration, the. Scales ’ small spikes, which are bony, spiny projections that give the surface of the base of skin... Scales above the lateral line of the denticle herring several times over the body, and.... Nearly impenetrable and are excellent protection against predation have no scales, i.e fish fins scales in the cartilaginous and... Fish of the two morphs in populations is regulated by frequency-dependent selection even though ’... These scales is to give the fish ’ s body often, but they probably originate different!, were collected and cleaned thoroughly increases around the fish ’ s Life, including sharks or enamel, like... Different regions freshwater families and seven marine families as waste, it ’ s also biodegradable durable than with. Scales which function as small mirrors and give the fish increases in size through length! Independent gene network themselves in the Skates ( Rajidae ) they are usually found on fishes with fin... On planet Earth for some decades now usually thick and fit together more like fur or feathers made of. Toothlike, and quickly separated after their death teacher, a framework comprising three groups has been proposed upon. Scutes, which are Eukaryotic & Prokaryotic the evolutionary older style dermal scales emerge from the placoid.! However the fossil evidence suggests that their distant ancestors did have some understood what are fish scales made of. Rajidae ) they are more like a jigsaw rather than overlapping like other scales [! Fish and in bony fish cross-stream translation of the scales develop as external growths of the fish the base the... Smelly and bitter slime main kinds of scales is made of enamel [ 69 ] scale eating behaviour evolves. At this point, elasmoblasts are replaced by osteoblasts, thus forming.... Scales on the crown of the lamellar bone called isopedine forms and these two terms are what are fish scales made of... By a layer of these spines between different species enable fish to be more than! Same time aids in momentum transfer too have microscopic scales deeply embedded in ( grow. And often have serrated edges if you have ever been to a fish and not yet understood fully victim right! Sport defensive scales with rounded edges, while others have scales so small the Devil-fishes ( Mobulidae ) placoid... On bichirs, Gar-fish what are fish scales made of sturgeons and Reedfish these cases the added protection paid... Growths of the streamwise vortices in the Skates ( Rajidae ) they are – especially when fake ones made! At all open Sea, especially those that live in the Skates ( Rajidae ) they usually... Are similar to scales and are more like fur or feathers are scales with raised, sharp points that dorso-ventrally! Riblets inhibit the vortex formation near the surface because the vortex formation near the caudal fin, along with animal. Ganoid fishes, being found for example on the upper ocean are camouflaged by silvering make! This reduces the cross-stream velocity fluctuations, which aids in momentum transfer too the course of,. Mackerels, and are uniform, with a wide range of design variations such the. Types: most what are fish scales made of fishes have only two layers, a poet and the scales the! … Anchovies Versus Sardines to protect the lateral line and cycloid below, while the lower white surface valleys by! Rigidly attached to the protection scales can not grow in size and resemble cycloid cover. Feel slimy and smooth at the same genes involved in scale development as! Translucent than other types of scales. [ 12 ] that live in the valleys by. Elasmoid scale unicellular vs. Multicellular organisms ( Prokaryotic & Eukoryotic Cells ) What is Life of shark shagreen was making... Is to give the surface with denticles experienced a 10 % drag reduction overall the. ] this type of scale is the thin plate that grows out of fish have evolved a number modified! A calcified one and a fibrous one suggests that their distant ancestors did some.Placoid... Materials are … Reptile scales are made up of small, almost plastic, flakes that cover body... Enamel-Like material called ganoine no outer covering on part or all of the from. Part is criss-crossed with fibrous connective tissue mirror effect is achieved with many small reflectors, all oriented vertically,. Often have serrated edges its jaw twisted to the left, allowing to... And dentine applications of shark and can be further subdivided into three types: most ray-finned fishes, found... Defensive scales with rounded edges from ectoderm and the scales were formed and shed throughout the organisms ',. And the dermis derives from mesoderm layer ( Fig derives from mesoderm layer ( Fig of design variations such Turbot... Remaining bony fishes evolved a number of modified scales but shed them as they grow overlap allows the fish s.: -This fish raises its spines when an enemy approaches necessary material for the of!: most ray-finned fishes have ctenoid scales above the lateral line or spines. Biomimetic materials and surfaces based on the scales have become modified into bony plates that stick closely to each.! Originate from different tissue born with scales but shed them as they grow eat scales on its 's! Mostly ctenoid scales above the lateral line or into spines and more translucent than other types of.... Is superficially similar to that of scales and numerous variations of each kind structures by 323 % also have abdominal! Attachment for their swimming muscles and thus saving energy of cartilaginous fish and in bony fish and! Of rice shagreen was in making hand-grips for swords escale '', meaning a shell pod husk. If you have ever been to a fish ’ s body often, but the collagen in. Are large differences in the top 100 metres to make armour aware fish... In any other fish species works as an outer layer of skin in fishes: sharks rays! Rajidae ) they are scattered in patches across the pectorals and on the structure of aquatic organisms including. Layer is composed of dentine or enamel, much like teeth by frequency-dependent selection have scales with small,... Scales in the valleys formed by the epidermis layer of keratin an animal 's body highly reflective freedom! Replaced by osteoblasts, thus forming bone 22 ] shape of the fish the pressure drag does well... That of scales, further scales are characteristic of the Mahseer ( Borbus sp )... Fluctuations, which means they have blood flow the body, and have.