Puffer fish and their relatives are a diverse group of tropical- and warm-temperate-dwelling species. They are primarily marine and many live and breed in the open ocean or offshore bays.
They are commonly recognized by their short, stout body shape, small fins and large eyes. They also have an unusual ability to inflate their bodies by swallowing water, which turns them into a ball like structure several times larger than their normal size.
Vertebrae
The skeleton of every kind of fish, as well as most other vertebrate animals, includes bones called vertebrae. These bones support the animal’s body weight and help it move.
Many fishes also have spines, which are spiky structures that protrude from the skin. Pufferfish, for example, have spiky skin that they use to protect themselves from predators like sharks and eels.
Spines can be long and slender or short and round. They also have different colors and shapes, depending on the species.
Vertebrae are a vital part of fishes’ skeletal structure because they help the fishes stay upright in water, even when they are moving. In addition to supporting the fish’s bodyweight, vertebrae are essential for helping a fish breathe and filter oxygen from the air.
These vertebrae are also important for keeping the fish moving smoothly as it swims, and are a good place to store energy in case the animal needs to stop and rest.
The vertebrae of pufferfish are a lot different than those in other fish, however. Instead of having a solid bone structure, the vertebrae in pufferfish are made up of lots of thin bones that make them flexible and able to bend.
This makes it easier for them to move around and get around in the water.
Another way they get around is by inflating themselves, a defensive method that allows them to appear much larger than they are when other fish or wading birds attack them.
Unlike triggerfishes, which inflate by blowing air into their stomachs, pufferfish inflate by rapidly pumping water into their bodies.
To inflate, the gill slits clamp shut and a powerful valve flips up over the inside of the mouth cavity to allow the pufferfish to take in lots of water at one time.
Inflating by pumping water into their bodies isn’t just a cool new trick: it’s actually an adaptation of their stomachs that they have used for thousands of years to survive in muddy and rocky waters.
While pufferfish can take in large amounts of water in their lungs, they don’t need to do this when they’re swimming because they have a stretchy stomach that allows them to quickly fill up their peritoneal cavities.
Ribs
If you have ever seen a puffer fish in an aquarium, you might think that it has a strange skeleton. These stiff fish don’t bend very easily, so their skeleton is weird and spiky!
The ribs in a puffer fish skeleton are very important and have a lot to do with their overall shape. These bones are called cartilage, which means that they are made of a special type of tissue that absorbs shock and gives the body flexibility. This makes it easier for sharks to maneuver around under water, where they have to dive deep and change pressures quickly.
This cartilage also allows sharks to bend their bodies up to 180 degrees, which is something that most other animals can’t do. The cartilage also cushions the shark’s internal organs and delicate structures inside their bodies when they dive into deep ocean waters.
But the ribs in a puffer fish’s skeleton are also important because they help the fish keep its inflated stomach safe from predators, including other fish!
When a pufferfish is threatened by a predator, it will “puff up” its stomach to make it larger and tougher. It does this by sucking in water and pumping it into its stomach, which expands to up to three times its normal size.
It’s actually a pretty cool trick that helps puffers defend themselves from other predators. When a pufferfish inflates, its spines become visible to other predators, making it hard to bite or swallow.
Some pufferfish even puff up their entire bodies when they’re threatened to prevent predators from snatching them!
A recent study has shown that the ribs in a pufferfish’s skeleton actually have nothing to do with the shape of its stomach. Instead, these ribs serve as support for the pufferfish’s skin.
When a fish’s skin is stretched tight, it can be very painful. That’s why it is important that a pufferfish only puff up when they are threatened.
Inflating the skin of a pufferfish can also give them the extra flexibility they need to fight off predators, says biologist Elizabeth Brainerd at the University of Massachusetts at Amherst. It also helps them eat more efficiently and stay healthy.
Pelvic Appendages
The pelvic appendages in a puffer fish skeleton are important to their ability to move on land, and also serve as protection for the body. In the case of pufferfish, this function is mainly to prevent predators from eating them. However, there are other purposes for the pelvic appendages in vertebrates.
The skeletal structure of the pelvis can be divided into a distal skeleton and a proximal skeleton. The distal skeleton includes the pelvic girdle and the pubis. The proximal skeleton includes the vertebrae and ribs.
When comparing the pelvic appendages in different actinopterygian fishes, one can see a wide range of shape and size. From nearly spheroidal in pufferfishes to extremely elongate in snipe eels with almost every shape in between.
Despite this diversity of body shape and size, all actinopterygians have a common developmental history. These animals were among the first to develop paired fins and limbs, which eventually evolved into a pair of hindlimbs.
This transition from paired fins to hindlimbs was one of the most important changes in early tetrapods’ evolutionary development. This transformation was accompanied by the development of a robust weight-bearing pelvis and the elaboration of the distal skeleton (Boisvert, 2005; Johanson et al. 2007).
It is known that Hox expression is involved in the formation of limb buds. This is primarily driven by the 3′ telomeric landscape (where paralogues of HoxD1-13 are expressed) and is induced during early phase patterning in the proximal limb. This regulatory switch from a permissive domain to an inhibitory domain is thought to determine limb-bud position.
In addition to HoxD, the lateral mesoderm is also involved in the formation of limb buds. In mice, this process involves the expression of a cluster of genes known as the Evx2 gene family. This group of genes is involved in the initiation and expansion of limb bud formation (Zhao et al. 2009).
Our studies suggest that the expression of HoxD paralogues in the lateral mesoderm during nascent pelvic fin/hindlimb bud formation is different from the patterning observed for nascent pectoral fins. This difference may be due to the lack of a 5′ centromeric landscape for HoxD paralogues in paddlefish.
Spines
The skeleton of a puffer fish, also called blowfish, is covered with spines. Spines are spiky skin structures that appear on certain areas of the body when the fish is threatened or injured.
The spines in a puffer fish skeleton are important because they help protect the fish from predators. In fact, they’re the reason that the puffer fish is able to “puff up.”
Pufferfish are tropical and subtropical sea fish that can be found in both freshwater and salt water. They range in size from a 1-inch-long dwarf or pygmy puffer to a freshwater giant that can reach more than 2 feet long.
They are considered bony fish because they have a skeletal structure rather than cartilage. This makes them very different from other types of fish, like sturgeon or octopus, which are cartilage-covered animals.
During their development, the embryos of pufferfish possess a series of genes that give rise to the spines on their skin. These are similar to the gene networks that allow birds to grow feathers and mammals to have hairs.
These genes were manipulated using CRISPR-Cas9 technology and other genetic techniques to study the development of the spines in a pufferfish. By manipulating these genes, the scientists were able to reduce the number of spines and loosen the restriction on where they appeared on the fish.
As a result, the researchers were able to see that some of the genes that were involved in the development of these spines were actually related to other organs in the puffer fish skeleton, like the mouth and digestive system. This suggests that the spines evolved from other parts of the skeleton, such as the jaw and stomach, which were later replaced by the spines on the fish’s skin.
The spines in a puffer fish are very unique, and they’re the reason that puffer fish can “puff up.” When a puffer ingests large amounts of water or air, it suddenly expands into a huge ball several times its original size. This inflated form is very difficult to bite and doesn’t appeal to predators.