Class OSTEICHTHYES
This class includes all bony fishes. Osteichthyes account for 96% of all fish species.
MOVEMENT STRUCTURES/TYPE
All osteichthyes have pectoral, pelvic, dorsal, anal and caudal fins, that aid in swimming and maintaining balance. The paired pectoral fins and dorsal fin help the fish turn and change direction, and the paired pelvic fins and anal fin add stability.
All osteichthyes have pectoral, pelvic, dorsal, anal and caudal fins, that aid in swimming and maintaining balance. The paired pectoral fins and dorsal fin help the fish turn and change direction, and the paired pelvic fins and anal fin add stability.
BODY COVERING; CELL LAYERS; LEVEL OF ORGANISATION; PROTECTION
Osteichthyes are cold blooded vertebrates with scales, paired fins, one pair of gill openings, jaws, and paired nostrils. Bony fish have scales. Most fish species have pigmentation that can be used as camouflage.
Osteichthyes are cold blooded vertebrates with scales, paired fins, one pair of gill openings, jaws, and paired nostrils. Bony fish have scales. Most fish species have pigmentation that can be used as camouflage.
SUPPORT
Osteichthyes have a skeletal structure made of bone. The vertebral column, cranium, jaw, and ribs make up the fish’s skeleton. The typical fish body shape is roughly cylindrical and tapered at both ends. This body shape is efficient for swimming as it creates less drag through the water.
Osteichthyes have a skeletal structure made of bone. The vertebral column, cranium, jaw, and ribs make up the fish’s skeleton. The typical fish body shape is roughly cylindrical and tapered at both ends. This body shape is efficient for swimming as it creates less drag through the water.
OBTAINING NUTRIENTS
Osteichthyes range from being herbivores, carnivores, omnivores, and even detritivores, depending on the species. Most bony fishes have mouths at the front end of their heads. Some bottom-feeding species have mouths on the underside of the snout, angled towards the bottom. Surface-feeding species have mouths that are angled upwards. Common osteichthyes diets include annelid worms, marine snails, mussels, clams, crabs, insects, birds, amphibians, small mammals and even other fish. Many bony fish are predators that select weak prey, as they are easier to obtain.
Osteichthyes range from being herbivores, carnivores, omnivores, and even detritivores, depending on the species. Most bony fishes have mouths at the front end of their heads. Some bottom-feeding species have mouths on the underside of the snout, angled towards the bottom. Surface-feeding species have mouths that are angled upwards. Common osteichthyes diets include annelid worms, marine snails, mussels, clams, crabs, insects, birds, amphibians, small mammals and even other fish. Many bony fish are predators that select weak prey, as they are easier to obtain.
RESPIRATION
Most species have a single pair of gill openings that are protected by a flexible plate called an operculum. They have an operculum that helps them breathe without having to swim. Water enters the gill chamber through the fish’s mouth and exists through the gill openings under the operculum. The blood flowing through the gill filaments absorbs oxygen from the water. Species with a lung go to the water's surface to breathe air. The lung is surrounded by veins that bring blood that needs to be oxygenated. Many species have a gas filled bladder called a swim bladder.
Most species have a single pair of gill openings that are protected by a flexible plate called an operculum. They have an operculum that helps them breathe without having to swim. Water enters the gill chamber through the fish’s mouth and exists through the gill openings under the operculum. The blood flowing through the gill filaments absorbs oxygen from the water. Species with a lung go to the water's surface to breathe air. The lung is surrounded by veins that bring blood that needs to be oxygenated. Many species have a gas filled bladder called a swim bladder.
CIRCULATION
Osteichthyes have a closed circulatory system with one main circuit. Their heart has two chambers with an atrium and a ventricle. The sinus venosus gets deoxygenated blood from the body, travels to the atrium which is pumped to the ventricle. The blood-filled ventricle forces the blood through the bulbus arteriosus, which then flows to the ventral aorta. The blood then flows to the gills where it is oxygenated, which then circulates to the organs of the head and body, and eventually returns to the sinus venosus.
Osteichthyes have a closed circulatory system with one main circuit. Their heart has two chambers with an atrium and a ventricle. The sinus venosus gets deoxygenated blood from the body, travels to the atrium which is pumped to the ventricle. The blood-filled ventricle forces the blood through the bulbus arteriosus, which then flows to the ventral aorta. The blood then flows to the gills where it is oxygenated, which then circulates to the organs of the head and body, and eventually returns to the sinus venosus.
EXCRETION
Osteichthyes esophagus is flexible enough for large objects to be swallowed. Most species of bony fish have a stomach that is bent in a "U" or "V" shape. The stomach's gastric glands release substances that help break down the food for digestion. The fish's blind sacs called pyloric caeca, is where their food is digested. The foods nutrients are absorbed in the intestine, and the waste is excreted through the anal opening.
Osteichthyes esophagus is flexible enough for large objects to be swallowed. Most species of bony fish have a stomach that is bent in a "U" or "V" shape. The stomach's gastric glands release substances that help break down the food for digestion. The fish's blind sacs called pyloric caeca, is where their food is digested. The foods nutrients are absorbed in the intestine, and the waste is excreted through the anal opening.
RESPONSE
Osteichthyes have a lateral lie that runs across the side of their body. This line is a series of sensory organs called neuromasts, that help the fish sense vibrations, water pressure, navigate, and locate prey. The nervous system of fishes is poorly developed compared to other vertebrates. Osteichthyes brain consists of the fore brain, the mid brain, and the hind brain. The fore brain controls the fish’s ability to smell, the mid brain is responsible for vision, learning, and motor responses, and the hind brain coordinates movement and balance. They do not have external openings to the ears and instead sound waves travel through soft tissue to the ears. In some species, the swim bladder lies against the ear and acts as an amplifier to enhance sound detection. Osteichthyes have well-developed eyes and sense of smell.
Osteichthyes have a lateral lie that runs across the side of their body. This line is a series of sensory organs called neuromasts, that help the fish sense vibrations, water pressure, navigate, and locate prey. The nervous system of fishes is poorly developed compared to other vertebrates. Osteichthyes brain consists of the fore brain, the mid brain, and the hind brain. The fore brain controls the fish’s ability to smell, the mid brain is responsible for vision, learning, and motor responses, and the hind brain coordinates movement and balance. They do not have external openings to the ears and instead sound waves travel through soft tissue to the ears. In some species, the swim bladder lies against the ear and acts as an amplifier to enhance sound detection. Osteichthyes have well-developed eyes and sense of smell.
REPRODUCTION
Most osteichthyes species have separate male and female individuals, but some are hermaphrodites. They reproduce sexually through either internal or external fertilization. For external fertilization, eggs and sperm and freely released into the water and become fertilized. For internal fertilization, osteichthyes mate. Oviparous osteichthyes females release fertilized eggs, leading the embryo to develop in a yolk sac outside of the body. In ovoviviparous osteichthyes, the females keep the fertilized eggs inside her body and the developing embryo is nourished by a yolk sac that was formed prior to fertilization. In viviparous osteichthyes, the fertilized eggs are kept inside the female and the developing embryo is nourished by the mother. Many species do not give parental care to the young after the eggs have hatched.
Most osteichthyes species have separate male and female individuals, but some are hermaphrodites. They reproduce sexually through either internal or external fertilization. For external fertilization, eggs and sperm and freely released into the water and become fertilized. For internal fertilization, osteichthyes mate. Oviparous osteichthyes females release fertilized eggs, leading the embryo to develop in a yolk sac outside of the body. In ovoviviparous osteichthyes, the females keep the fertilized eggs inside her body and the developing embryo is nourished by a yolk sac that was formed prior to fertilization. In viviparous osteichthyes, the fertilized eggs are kept inside the female and the developing embryo is nourished by the mother. Many species do not give parental care to the young after the eggs have hatched.