Many fish species evolved parts of their fins into sharp, spiny, needle-like elements — called fin spines — that function to protect the fish against predators.
What is the spine of a fish?
The vertebral column of fish is differentiated in two regions: the trunk vertebrae, which cover the portion of the body between the skull and the tail, and the caudal spine [50].
Do fish fins have spines?
Spines can be present on the dorsal, pectoral, anal and pelvic fins (figure 1). Fishes with fin spines projecting in the horizontal plane (pectoral-fin spines) should increase their body width, whereas those with spines on the vertical axis (dorsal-fin, anal-fin or pelvic-fin spines) should increase in body depth.
What are spines in dorsal fins?
Some animals have developed dorsal fins with protective functions, such as spines or venom. For example, both the spiny dogfish and the Port Jackson shark have spines in their dorsal fins which are capable of secreting venom.
Why do fish have dorsal spines?
Dorsal fins. The dorsal fins increase the lateral surface of the body during swimming, and thereby provide stability but at the expense of increasing drag (see also BUOYANCY, LOCOMOTION, AND MOVEMENT IN FISHES | Maneuverability).
What are fish spines made of?
The skeleton, which forms the support structure inside the fish, is either made of cartilage (cartilaginous fish) or bone (bony fish). The main skeletal element is the vertebral column, composed of articulating vertebrae which are lightweight yet strong.
What is the spine?
The spine (aka backbone) is a linked column of bones running from the head down to the lower back. Bone segments form the column. One bone segment is a vertebra, and multiple bone segments are vertebrae.
What are fin spines made of?
They have skeletons made of bone, and can be contrasted with cartilaginous fishes which have skeletons made of cartilage. Bony fishes are divided into ray-finned and lobe-finned fish. Most fish are ray-finned, an extremely diverse and abundant group consisting of over 30,000 species.
What’s the purpose of fish fins?
Almost all fish have fins that they use for swimming (locomotion), balance, stability, and steering. A catfish has dorsal, adipose, caudal, anal, paired pelvic, and paired pectoral fins.
How do fish fins work?
Nerves in the pectoral fins of fish detect the fin rays’ position and how much they bend as they move through the water, which helps the fish sense speed and the relative position of their fins. The shape of the fin affects how the fish will move too.
Which part of the fish protects the gills?
Operculum
Operculum: The operculum is the bony flap that protects the gills from harm. It opens and closes to allow water to pass over the gills.
Do dorsal fins grow back?
In some case, you may need to use antibiotics to allow your fish to regrow fins. Usually, a fish will regrow fins without incident. But sometimes, fin rot and other disease may impair its ability to do so. If you see signs of infection and salt doesn’t help, consider purchasing antibiotics from the pet shop.
Why do dorsal fins collapse?
Collapsed or collapsing dorsal fins are rare in most wild populations and usually result from a serious injury to the fin, such as from being shot or colliding with a vessel.
Can fish swim without fins?
It can’t swim without its fins, and it slowly sinks toward the ocean bottom, where it suffocates or is eaten alive by other fish. Why do fishermen do it?
What is the function of the second dorsal fin?
The second dorsal fin is located on the back of the shark midway between the first dorsal fin and the tail. The second dorsal fin, much like the first dorsal fin, helps to stabilize the shark in the water. The second dorsal fin helps the shark swim steadily and maneuver the back of it’s body more easily.
Can fishes feel pain?
“Fish do feel pain. It’s likely different from what humans feel, but it is still a kind of pain.” At the anatomical level, fish have neurons known as nociceptors, which detect potential harm, such as high temperatures, intense pressure, and caustic chemicals.
Do fish have balls?
Most male fish have two testes of similar size. In the case of sharks, the testes on the right side is usually larger. The primitive jawless fish have only a single testis, located in the midline of the body, although even this forms from the fusion of paired structures in the embryo.
Does fish get thirsty?
As well as getting water through osmosis, saltwater fish need to purposefully drink water in order to get enough into their systems. Where their freshwater counterparts direct all of the water that comes into their mouths out through their gills, saltwater fish direct some into their digestive tract.
What is the purpose of the spine?
It gives your body structure and support. It allows you to move about freely and to bend with flexibility. The spine is also designed to protect your spinal cord. The spinal cord is a column of nerves that connects your brain with the rest of your body, allowing you to control your movements.
What are the 3 main functions of the spine?
The three main functions of the spine are to: Protect the spinal cord, nerve roots and several of the body’s internal organs. Provide structural support and balance to maintain an upright posture. Enable flexible motion.
What are the 4 main functions of the spine?
Your spine, or backbone, is your body’s central support structure. It connects different parts of your musculoskeletal system. Your spine helps you sit, stand, walk, twist and bend.