Tetraodontidae is a Tetraodontiformes family of predominantly marine and estuary fish. Pufferfish, puffers, balloonfish, blowfish, blowies, bubblefish, globefish, swellfish, toadfish, toadies, honey toads, sugar toads, and sea squab are all members of the family. Puffer fish are characterized by their enormous exterior spines (unlike the thinner, hidden spines of the Tetraodontidae, which are only visible when the fish have puffed up). The scientific name relates to the four massive teeth fused into an upper and lower plate that are used to shatter the hard shells of their natural food, crustaceans and mollusks.The majority of pufferfish species are deadly, and several are among the world's most dangerous vertebrates. Internal organs of certain species, such as the liver and occasionally the skin, contain tetrodotoxin, which is very harmful to most animals when consumed.
Pufferfish are some of the oddest fish in the water, especially since they have a skeleton that is significantly reduced. They can form a ball out of their bodies without breaking any bones. They have fused skull and jaw bones in their head area.
A young pufferfish's first set of teeth are set in a normal row along the jaw,the beak consists of paired upper and lower elements, each made up of a stack of elongated laminar teeth that consist almost entirely of enameloid and that are cemented together in a matrix of hard tissue. The individual teeth making up each element of the beak are members of the same tooth family, so that those at the cutting edge are older than those at the base. A cutting edge at the margin of the beak is maintained by differential wear of the tooth enameloid and of the surrounding bone. Tooth formation is intraosseous, so that as the teeth wear away at the cutting edge, the beak is replenished by addition of new teeth initiated and formed in a cavity at the base of the beak. Soon after the formation of an individual tooth is complete, hard tissue is laid down around it, to incorporate it into the beak. the teeth that replace them when they wear down are very different.
Only a single replacement tooth forms in each quarter of the jaw. It elongates and eventually stretches across the entire jaw. New bands of replacement teeth then form underneath, in the jaw cavity. They make a stack that fuses together as the teeth grow, creating the beak. Stages of tooth development in a pufferfish, showing clockwise from top left: the change from teeth, to bands, to the beginnings of a beak. The teeth and bands are stained red. The unusual beak of the pufferfish is produced by small tweaks to the normal programme of tooth development.Most fish, unlike humans, produce new generations of teeth throughout their life. This requires a source of stem cells, which have the potential to develop into many different cell types and can be programmed to transform into the cells that build a tooth.
The stem cells are usually located in the jaw, just below where the teeth will form. In the pufferfish, however, the stem cells are located outside of the jaw. Their access to the cavity in which the replacement teeth form is restricted to a single small opening in each quarter of the jaw.
Stem cells are able to enter via these openings and move up through the jaw cavity to reach the four sites where the new teeth will grow. The beak, ideal for crunching through prey such as shellfish, is composed of elongated teeth that are fused together.
They have spiky skin structures – in certain patches around the body. These fish also lack some ribs and have no pelvis, allowing them to become globular shaped. Their skin is also adapted for stretching and the dermis layer contains lots of collagen fibres that allow it to expand by 40%. The spines of pufferfish composed of nanocrystalline hydroxyapatite, protein(collagen), and water, the same materials as scales.Indeed, these spines are just modified scales. And like other scales, these spines originate during development from the mesoderm layer of the dermis or the skin. These spikes on their body are very poisonous, which are highly toxic to both animals and humans. Almost all species of puffer fish contain tetrodotoxin, which can be 1,200 times stronger than cyanide.
The following are the differences between typical bony fish and puffer fish:
- Oceans are dominated by bony fish. They are distinguished from cartilaginous fish by having bone skeletons and a swim bladder that allows them to float. Most bony fish species have fusiform, hydrodynamic bodies that allow them to glide through the water at high speeds. Other species have flat bodies and live at the sea's bottom. When frightened, puffer fish, for example, inflate themselves to a globe many times their regular size by ingesting water.
- The skeleton of a pufferfish lacks ribs and pelvic fins, and the skull and jaw have fused bones. The lower complexity of the pufferfish Hox complexes is thought to be the cause of the secondarily simplified pufferfish morphology. Bony Fish have two sets of ribs that connect to the upper and lower regions of the vertebral arches but do not meet in the front. The ribs of terrestrial vertebrates are thought to have originated from the top (dorsal) pair of ribs.
- The skin of puffer fish is designed for stretching, and the dermis layer includes many collagen fibers that allow it to extend by 40%. Other bony fish, unlike puffer fish, are unable to enlarge.
- Pufferfish are the only bony fish that can close their eyes, and we've figured out how. They drop their eyes deep into their sockets, then pucker the skin around their eyes together, as if sealing the aperture of a camera.
- There are no scales on puffer fish. They usually have spines instead. The spines of these ordinarily lie flat, but as they puff up, they stand upright. Scales cover the majority of bony fish.
The puffer fish, also known as blowfish, balloonfish, or bubblefish. They may expand to several times their normal size when assaulted by consuming water or air; porcupinefish, which have massive conspicuous spines, have a similar response (unlike the small, almost sandpaper-like spines of puffer fish). Tetraodon is named because its four huge teeth, which are fused into an upper and lower plate and utilized to break the shells of its native food, crus taceans and mollusks. Tetrodotoxin, a substance found in pufferfish, is a strong neurotoxin that may kill over 60% of humans who consume it. Although a human only needs a few milligrams of the poison to die, the flesh is nonetheless regarded as a delicacy in Japan and Korea.