"first appeared in the fossil record in the Cambrian. The first known asterozoans were the Somasteroidea, which exhibit characteristics of both groups. Starfish are infrequently found as fossils, possibly because their hard skeletal components separate as the animal decays. Despite this, there are a few places where accumulations of complete skeletal structures occur, fossilized in place in Lagerstätten — so-called ""starfish beds"". By the late Paleozoic, the crinoids and blastoids were the predominant echinoderms, and some limestones from this period are made almost entirely from fragments from these groups. In the two major extinction events that occurred during the late"
"Spiny dogfish The spiny dogfish, spurdog, mud shark, or piked dogfish (""Squalus acanthias"") is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. While these common names may apply to several species, ""Squalus acanthias"" is distinguished by having two spines (one anterior to each dorsal fin) and lacks an anal fin. It is found mostly in shallow waters and further offshore in most parts of the world, especially in temperate waters. Spiny dogfish in the northern Pacific Ocean have recently been reevaluated and found to constitute a separate species,"
"collagen fibres. Starfish are included in the subphylum Asterozoa, the characteristics of which include a flattened, star-shaped body as adults consisting of a central disc and multiple radiating arms. The subphylum includes the two classes of Asteroidea, the starfish, and Ophiuroidea, the brittle stars and basket stars. Asteroids have broad-based arms with skeletal support provided by calcareous plates in the body wall while ophiuroids have clearly demarcated slender arms strengthened by paired fused ossicles forming jointed ""vertebrae"". The starfish are a large and diverse class with about 1,500 living species. There are seven extant orders, Brisingida, Forcipulatida, Notomyotida, Paxillosida, Spinulosida,"
"Spiny eel The name spiny eel is used to describe members of two different families of fish: the freshwater Mastacembelidae of Asia and Africa, and the marine (and generally deep sea) Notacanthidae. Both are so-named because of their eel-like shape and sturdy fin spines. These two families are not related: the Notacanthiformes belong to the Superorder Elopimorpha, whose members are characterized by having leptocephalus larvae. The freshwater Mastacembelids do not share this characteristic and are popular specimens in the aquarium trade. Mastacembelid Spiny eels originate from three places. The Middle East, Southeast Asia and Africa. In Africa alone there are"
"Spiny lobster Spiny lobsters, also known as langustas, langouste, or rock lobsters, are a family (Palinuridae) of about 60 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also, especially in Australia, New Zealand, Ireland, South Africa, and the Bahamas, called crayfish, sea crayfish, or crawfish (""kreef"" in South Africa), terms which elsewhere are reserved for freshwater crayfish. The furry lobsters (""e.g."" ""Palinurellus"") were previously separated into a family of their own, the Synaxidae, but are usually considered members of the Palinuridae. The slipper lobsters (Scyllaridae) are their next-closest relatives, and these two or three families make up"
"the quota with nearly being added. As a cartilaginous fish, shark tissues usually do not fossilize. Squalus acanthias fossils date back to the Miocene 11 MYA. Spiny dogfish The spiny dogfish, spurdog, mud shark, or piked dogfish (""Squalus acanthias"") is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. While these common names may apply to several species, ""Squalus acanthias"" is distinguished by having two spines (one anterior to each dorsal fin) and lacks an anal fin. It is found mostly in shallow waters and further offshore in most"
"family (""Jasus"", ""Projasus"", and the furry lobster ""Palinurellus""), and its form can distinguish different species. Spiny lobster Spiny lobsters, also known as langustas, langouste, or rock lobsters, are a family (Palinuridae) of about 60 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also, especially in Australia, New Zealand, Ireland, South Africa, and the Bahamas, called crayfish, sea crayfish, or crawfish (""kreef"" in South Africa), terms which elsewhere are reserved for freshwater crayfish. The furry lobsters (""e.g."" ""Palinurellus"") were previously separated into a family of their own, the Synaxidae, but are usually considered members of the Palinuridae. The"
"Acanthodii Acanthodii or acanthodians (sometimes called spiny sharks) is a paraphyletic class of teleostome fish, sharing features with both bony fish and cartilaginous fish. In form they resembled sharks, but their epidermis was covered with tiny rhomboid platelets like the scales of holosteans (gars, bowfins). They represent several independent phylogenetic branches of fishes leading to the still extant Chondrichthyes. The popular name ""spiny sharks"" is a partial misnomer for these early jawed fishes. The name was coined because they were superficially shark-shaped, with a streamlined body, paired fins, and a strongly upturned tail; stout, largely immovable bony spines supporting all"
"Sternoptychidae The marine hatchetfishes or deep-sea hatchetfishes as well as the related bottlelights, pearlsides and constellationfishes are small deep-sea ray-finned fish of the stomiiform family Sternoptychidae. They are not closely related to and should not be confused with the freshwater hatchetfishes, which are teleosts in the characiform family Gasteropelecidae. The Sternoptychidae have 10 genera and about 70 species altogether. The scientific name means """"Sternoptyx""-family"", from ""Sternoptyx"" (the type genus) + the standard animal family suffix ""-idae"". It ultimately derives from Ancient Greek ""stérnon"" (στέρνον, ""breast"") + ""ptýx"" (πτύξ, ""a fold/crease"") + Latin ""forma"" (""external form""), the Greek part in reference"
"crescent from Kamchatka to Alaska and as far south as the coast of Oregon. Acantholiparis opercularis Acantholiparis opercularis, or the spiny snailfish, is one of two species within the snailfish genus ""Acantholiparis"". The generic name comes from the Greek ""akantha"" meaning ""thorn"" and ""liparis"" meaning ""fat"". The specific name comes from the Latin ""opercularis"", meaning covered (as in a lid). The spiny snailfish is a small fish, with a length up to 7 cm. The spiny snailfish is a deep-water fish, known from depths between 227 m and 3600 m. It is a demersal fish, living just above the seabed."
"Squalidae The Squalidae, also called dogfish sharks or spiny dogfishes, are a family of sharks in the order Squaliformes. They have two dorsal fins, each with smooth spines, but no anal fin, and their skin is generally rough to the touch. Unlike virtually all other shark species, dogfish sharks possess venom which coats their dorsal spines – this venom is mildly toxic to humans. These sharks are characterized by teeth in upper and lower jaws similar in size; a caudal peduncle with lateral keels; the upper precaudal pit usually is present; and the caudal fin is without a subterminal notch."
"Rabbitfish Rabbitfishes or spinefoots are perciform fishes in the family Siganidae. The 29 species are in a single genus, Siganus. In some now obsolete classifications, the species having prominent face stripes—colloquially called foxfaces–are in the genus ""Lo"". Other species, such as the masked spinefoot (""S. puellus""), show a reduced form of the stripe pattern. Rabbitfishes are native to shallow waters in the Indo-Pacific, but ""S. luridus"" and ""S. rivulatus"" have become established in the eastern Mediterranean via Lessepsian migration. They are commercially important food fish, and can be used in the preparation of dishes such as ""bagoong"". All rabbitfish have"
"Climatiiformes The Climatiiformes is an order of extinct fish belonging to the class Acanthodii. Like most other ""spiny sharks"", the Climatiiformes had sharp spines. These animals were rather small in size (about 4 in or 10 cm) and lived from the Late Silurian to the Early Carboniferous period. The type genus is ""Climatius"". The order splits into the suborders Climatiida and Diplacanthida, which themselves split into several families. Climatiiformes is a fish species which is on the verge of extinction. It belongs to kingdom Animalia and class Acanthodii. It has sharp spines on their body also called as “spiny sharks."
"Spinus (genus) Spinus is a genus of passerine birds in the finch family. It contains the North and South American siskins and goldfinches. The genus name is from the Ancient Greek ""spinos"", a name for a now-unidentifiable bird. All of the species in the genus other than the Tibetan serin were formerly included in the genus ""Carduelis"". They were moved to the resurrected genus ""Spinus"" based on phylogenetic studies of mitochondrial and nuclear DNA sequences. The Tibetan serin was formerly placed in the genus ""Serinus"". The Eurasian siskin and the Tibetan serin are the only species from the Old World"
"Echinoderm Echinoderm is the common name given to any member of the phylum Echinodermata (from Ancient Greek, ἐχῖνος, ""echinos"" – ""hedgehog"" and δέρμα, ""derma"" – ""skin"") of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as sea stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or ""stone lilies"". Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the"
"Notacanthidae The deep-sea spiny eels are a family, Notacanthidae, of fishes found worldwide below , and as deep as . The earliest known spiny eel is ""Pronotacanthus sahelalmae"", from the Santonian of what is now Lebanon. Their bodies are greatly elongated, though more tapered than in true eels. The caudal fin is small or nonexistent, while the anal fin is lengthy, as long as half of the total body length. They feed on animals attached to or living on the sea floor, such as sea anemones, echinoderms, molluscs, and worms. Although not true eels, these fish do have a similar"
"Starling Starlings are small to medium-sized passerine birds in the family Sturnidae. The name ""Sturnidae"" comes from the Latin word for starling, ""sturnus"". Many Asian species, particularly the larger ones, are called mynas, and many African species are known as glossy starlings because of their iridescent plumage. Starlings are native to Europe, Asia and Africa, as well as northern Australia and the islands of the tropical Pacific. Several European and Asian species have been introduced to these areas as well as North America, Hawaii and New Zealand, where they generally compete for habitats with native birds and are considered to"
"the first United States oceanographic research vessels, and from which it derives its specific name. The genus name is Latin for a headdress or tiara worn by ancient Persian kings. Although their appearance is quite variable, other members of the genus ""Cidaris"" have long cylindrical blunt or pointed spines that are not covered with skin as are most sea urchin spines. As a result, barnacles, tube worms and other epizoic organisms grow on them. The spines of ""C. blakei"" are present in three different forms, one form being broad, flat and paddle-shaped. They are also naked and epizoics grow on"
"Silurian placoderm, ""Entelognathus"", which has jaw anatomy shared with bony fish and tetrapods, has led to revisions of this phylogeny: acanthodians were then considered to be a paraphyletic assemblage leading to cartilaginous fish, while bony fish evolved from placoderm ancestors. Burrow et al. 2016 provides vindication by finding chondrichthyans to be nested among Acanthodii, most closely related to ""Doliodus"" and ""Tamiobatis"". A 2017 study of ""Doliodus"" morphology points out that it appears to display a mosaic of shark and acanthodian features, making it a transitional fossil and further reinforcing this idea. Acanthodii Acanthodii or acanthodians (sometimes called spiny sharks) is"
"Bay, Gulf of Alaska, Between 2006 and 2014"" (PDF). NOAA Technical Memorandum – via Science Direct. Pacific spiny dogfish The Pacific spiny dogfish (""Squalus suckleyi"") is a common species of the Squalidae (dogfish) family of sharks and are among the most abundant species of sharks in the world. This species is closely related to ""Squalus acanthias"" and for many years they were treated as a single species. Recent research, using meristic, morphological and molecular data led to the resurrection of Pacific Spiny Dogfish as a separate species. The American Fisheries Society recommends the common name ""Pacific Spiny Dogfish"" for ""Squalus"
"Acantholiparis opercularis Acantholiparis opercularis, or the spiny snailfish, is one of two species within the snailfish genus ""Acantholiparis"". The generic name comes from the Greek ""akantha"" meaning ""thorn"" and ""liparis"" meaning ""fat"". The specific name comes from the Latin ""opercularis"", meaning covered (as in a lid). The spiny snailfish is a small fish, with a length up to 7 cm. The spiny snailfish is a deep-water fish, known from depths between 227 m and 3600 m. It is a demersal fish, living just above the seabed. ""Acantholiparis opercularis"" lives generally near the coast, over a wide range stretching as a"
"and highly desired for aquaria. In addition to the name scorpionfish, informal names for family members include firefish, turkeyfish, dragonfish, and stingfish, usually with adjectives added. General characteristics of family members include a compressed body, ridges and/or spines on the head, one or two spines on the operculum, and three to five spines on the preopercle. The dorsal fin has 11 to 17 spines, often long and separated from each other, and the pectoral fins are well-developed, with 11 to 25 rays. The spines of the dorsal, anal, and pelvic fins all have venom glands at their bases. Most species"
"Strophurus Strophurus is a genus of lizards in the family Diplodactylidae. All species of ""Strophurus"" are endemic to Australia, and are sometimes given the common names spiny-tailed geckos or striped geckos. The species of this genus are long. The scales of the body are generally small and round, sometimes interspersed with enlarged scales and soft spines. All members of this genus have the unique defence, the ability to squirt a harmless, foul-smelling fluid from their tails, which can create a highly flammable substance when mixed with ammonia. This fluid is used to deter birds while they are perching in shrubbery,"
"species are commonly known by the highly ambiguous name ""killifish"" (the general term for egg-laying toothcarps), or the somewhat less ambiguous ""topminnow"" (a catch-all term for Fundulidae). ""Studfish"" is a quite unequivocal vernacular name applied to some other ""Fundulus"" species; it is not usually used to refer to the genus as a whole, however. There are currently 39 recognized species in this genus: Formerly placed in ""Fundulus"" were the closely related diamond killifish (""Adinia xenica"") and the somewhat more distantly related Cuban killifish (""Cubanichthys cubensis"", a pupfish). Fundulus Fundulus is a genus of ray-finned fishes in the superfamily Funduloidea, family"
"on the x-axis. <graph>{ }</graph> Triacanthidae Triacanthidae, commonly known as triplespines or tripodfishes, is a family of Indo-Pacific fishes. It is classified in the order Tetraodontiformes, along with the pufferfishes and the ocean sunfish. The family consists of seven species in four genera, in addition to one extinct genus that only is known from fossils. Much like their relatives the triggerfish and the filefish, the triplespines's first ray of the dorsal fin is formed to a spine. Further, they have two spines in place of their ventral fins. They have sharp and heavy teeth, which they use to eat hard-shelled"
"Pacific spiny dogfish The Pacific spiny dogfish (""Squalus suckleyi"") is a common species of the Squalidae (dogfish) family of sharks and are among the most abundant species of sharks in the world. This species is closely related to ""Squalus acanthias"" and for many years they were treated as a single species. Recent research, using meristic, morphological and molecular data led to the resurrection of Pacific Spiny Dogfish as a separate species. The American Fisheries Society recommends the common name ""Pacific Spiny Dogfish"" for ""Squalus suckleyi"" over alternatives such as ""Spotted Spiny Dogfish"" and ""North Pacific Spiny Dogfish"" and ""Spiny Dogfish"""
"the observation of sperm cells in the process of fertilising ova. The arm regeneration potential of brittle stars is being studied in connection with understanding and treating neurodegenerative diseases in humans. Echinoderm Echinoderm is the common name given to any member of the phylum Echinodermata (from Ancient Greek, ἐχῖνος, ""echinos"" – ""hedgehog"" and δέρμα, ""derma"" – ""skin"") of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as sea stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or ""stone lilies"". Echinoderms are found at every ocean"
"Stellifer Stellifer is a genus of fish in the family Sciaenidae, the drums and croakers. It is found in New World waters. Many species are known commonly as stardrums. In the Americas, this is one of the most diverse genera among the sciaenids. Its members can be found in the tropics and subtropics and in shallow and deeper waters. Some are semianadromous, spawning in the ocean near estuaries so the eggs and young will be taken into lower-salinity environments on the tides. The genus belongs to the subfamily Stelliferinae, whose members have double-chambered swim bladders (the smaller front chamber is"
"species is covered in small, gravel-like pustules (spots). Small, sandpaper-like spines can be found on the body, and when the animal ""puffs up"" they stick out and make it feel even more rough. Although the colour varies, ""T. hamiltoni"" is sandy to whitish in colour, with small brown spots over most of the back and upper sides, and brown bars and blotches beneath. ""T. glaber"" has larger spots and blotches, and less prominent spines, hence its common name, smooth toadfish. The genus ""Tetractenos"" was once classed as ""Tetraodon"" or ""Tetrodon"", and is sometimes also confused with ""Torquigener"". Tetractenos Tetractenos is"
"one spine each on the paired pelvic and pectoral fins, and on the aingle anal and two dorsal fins, and a further four pairs without fins on the fish's underside. Climatius Climatius (meaning ""inclined fish"" or ""tilted fish"") is an extinct genus of spiny shark. Fossils have been found in both Europe and North America. ""Climatius"" was an active swimmer judging from its powerful caudal fin and abundant stabilizing fins, and probably preyed on other fish and crustaceans. Its lower jaw was lined with sharp teeth which were replaced when worn, but the upper jaw had no teeth. It also"
"Triacanthidae Triacanthidae, commonly known as triplespines or tripodfishes, is a family of Indo-Pacific fishes. It is classified in the order Tetraodontiformes, along with the pufferfishes and the ocean sunfish. The family consists of seven species in four genera, in addition to one extinct genus that only is known from fossils. Much like their relatives the triggerfish and the filefish, the triplespines's first ray of the dorsal fin is formed to a spine. Further, they have two spines in place of their ventral fins. They have sharp and heavy teeth, which they use to eat hard-shelled molluscs and crustaceans. They also"
"Unlike the spiny snailfish, it is pelagic, living above the ocean floor rather than upon it as the demersal spiny snailfish does. ""A. caecus"" is a more southern fish than ""A. opercularis"", inhabiting an area off the coast of Oregon and northern California. Possibly the range extends as far north as British Columbia but this is unconfirmed. Acantholiparis caecus Acantholiparis caecus is one of the two snailfishes within the genus ""Acantholiparis"", along with ""A. opercularis"", the spiny snailfish. Its generic name comes from the Greek for thorny (akantha) and fat (liparis); its specific name comes from the Latin word for"
"Climatius Climatius (meaning ""inclined fish"" or ""tilted fish"") is an extinct genus of spiny shark. Fossils have been found in both Europe and North America. ""Climatius"" was an active swimmer judging from its powerful caudal fin and abundant stabilizing fins, and probably preyed on other fish and crustaceans. Its lower jaw was lined with sharp teeth which were replaced when worn, but the upper jaw had no teeth. It also had large eyes, suggesting that it hunted by sight. Although it was a small fish, at , to discourage predators, ""Climatius"" sported a total of fifteen sharp spines. There was"