Spines can be present on the dorsal, pectoral, anal and pelvic fins (figure 1).
What is pelvic fin?
Pelvic fins, lo- cated on the bottom of a fish in front of the anal fin, help balance the fish, keep it level and prevent it from rolling from side to side. Fish sometimes rest by sitting on their pelvic fins. Pectoral fins are located on either side of the fish near the gills.
Do fish have spines?
Fish are vertebrates, which means they have a skeleton that includes a spine and a skull. The main skeleton helps support and protect the soft parts of the fish’s body, such as the organs and muscles.
What are the spines for in a fishes fins?
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. Such spines have evolved independently in different lineages and are considered evolutionary drivers of fish diversity.
What is the function of the pelvic fin of a bony fish?
The function of the pelvic fins is as variable as their morphology between fish. They are used in swimming as an aerofoil, brake, propulsor, and rudder, for ground walking, and for hovering.
What are fish spines called?
The main external features of the fish, the fins, are composed of either bony or soft spines called rays which, with the exception of the caudal fins, have no direct connection with the spine.
Do dorsal fins have spines?
Spines can be present on the dorsal, pectoral, anal and pelvic fins (figure 1).
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 pelvic fins?
Pelvic Fin: The pelvic fin stabilizes the fish while swimming and allows for up-and-down movement in the water. Vent: The vent removes waste and extra water. It is also the outlet for eggs or milt (sperm) during spawning. Anal Fin: The anal fin stabilizes the fish while swimming.
Where are pelvic fins on a fish?
The pelvic fins are paired fins found on the ventral (bottom) side of fish. In teleost (bony) fishes, pelvic fins placement gives some indication of evolution. For more basal groups, the pelvic fins are located at mid-body in the abdominal region.
What is the pelvic bone made up of?
It is formed by contributions from all three of the pubis, ilium, and ischium. The structural integrity of the bony pelvis is maintained by various important joints and ligaments. The pubic symphysis and sacrococcygeal joint have been described earlier.
How many pelvic fins do fish have?
Fish don’t possess just a few fins, they have seven: one dorsal (down the back), two pectoral (one on each side), two pelvic (both mid bottom), one anal (back bottom), and of course the caudal (tail) fin. Each fin contributes to a fish’s ability to successfully survive and navigate its environment.
Do fish have two pelvic fins?
Fish have two sets of paired fins: pectoral and pelvic (Fig 4.25).
What are the lower fins on a fish called?
The bottom fin at the back of the fish is called the anal fin. The tail fin is called the caudal fin. Pectoral and pelvic fins come in pairs. Dorsal, anal, and caudal fins are single.
Where is pelvic fin?
The pelvic fins are paired fins found on the ventral (bottom) side of fish. In teleost (bony) fishes, pelvic fins placement gives some indication of evolution. For more basal groups, the pelvic fins are located at mid-body in the abdominal region.
Why do fish have pelvic fins?
Pelvic Fin: The pelvic fin stabilizes the fish while swimming and allows for up-and-down movement in the water. Vent: The vent removes waste and extra water. It is also the outlet for eggs or milt (sperm) during spawning. Anal Fin: The anal fin stabilizes the fish while swimming.
What is mean by caudal fin?
Definition of caudal fin
: the terminal fin of a fish or cetacean located behind the caudal peduncle : tail fin — see fish illustration.
Do fish have two pelvic fins?
Fish have two sets of paired fins: pectoral and pelvic (Fig 4.25).