Table of Contents
- 1 What trait defines the class actinopterygii?
- 2 What are the key traits in actinopterygii?
- 3 What characteristics are specific to Osteichthyes chondrichthyes?
- 4 What are the classes of Osteichthyes?
- 5 Is a goldfish an actinopterygii?
- 6 What type of tail do actinopterygii have?
- 7 How are actinopterygians classified into the subclasses?
- 8 Which is part of the skeleton does the Actinopterygii attach to?
What trait defines the class actinopterygii?
Actinopterygii (ray-finned fishes) Fins supported by rays of dermal bone rather than by cartilage.
What are the key traits in actinopterygii?
General Characters:
- Thin and elongated fishes.
- Body is covered by small cycloid scales. Head region is devoid of any scales. Some fishes are scaleless.
- Long dorsal and caudal fins are spineless. Fins may not be supported by fin rays.
- Mouth aperture is comparatively large.
- No accessory respiratory organs are present.
What are the characteristics of class osteichthyes?
Class – Osteichthyes Bony fishes share several distinguishing features: a skeleton of bone, scales, paired fins, one pair of gill openings, jaws, and paired nostrils. Osteichthyes includes the largest number of living species of all scientific classes of vertebrates, more than 28,000 species.
What are class actinopterygii organisms?
Classification
- Polypteriformes (Bichirs, Reedfishes)
- Acipenseriformes (Sturgeons, Paddlefish)
- Lepisosteiformes (Gars)
- Amiiformes (Bowfin)
- Osteoglossiformes (bony-tongued fishes)
- Hiodontiformes (mooneye, goldeneye …)
- Elopiformes (ladyfishes, tarpon … )
- Albuliformes (bonefishes)
What characteristics are specific to Osteichthyes chondrichthyes?
General characteristics of Chondrichthyes and Osteichthyes
| Characters | Chondrichthyes | Osteichthyes |
|---|---|---|
| Endoskeleton | Cartilaginous endoskeleton | Bony endoskeleton |
| Size | Large body | Smaller in size compared to Chondrichthyes |
| Position of mouth | Ventrally | Terminal |
| Scales | Placoid scales are present | Cycloid scales are present |
What are the classes of Osteichthyes?
Osteichthyes are divided into two subclasses: Sarcopterygii and Actinopterygii. Sarcopterygii, or lobe-finned fishes, include the lungfish and the coelacanth, and Actinopterygii, or ray-finned fishes, include salmon, herring, eels, anchovies, and clownfish, among many others.
What type of fish are in class Actinopterygii?
ray-finned fishes
The group of ray-finned fishes (Class Actinopterygii) encompasses over 20,000 species of fish that have ‘rays,’ or spines, in their fins. This separates them from the lobe-finned fishes (Class Sarcopterygii, e.g., the lungfish and coelacanth), which have fleshy fins.
How many species of Actinopterygii are there?
27,000 species
Diversity and Lower Taxonomy: The subclass Actinopterygii comprises some 27,000 species of ray-finned bony fishes, making it the largest radiation of any vertebrate group.
Is a goldfish an actinopterygii?
The actinopterygians include the most familiar fish, such as sturgeons, gars, eels, carp, herrings, anchovies, catfishes, goldfishes, piranhas, oarfish, seahorses, bass, cichlids, pickerel, salmon, and trout. …
What type of tail do actinopterygii have?
Their tails were heterocercal. On their bodies were thick ganoid scales that abutted each other, rather than overlapping as in most modern fishes.
What kind of scales does the Actinopterygii have?
Body of Actinopterygii is covered by ganoid, cycloid or ctenoid scales. In some cases scales are absent. 2. Generally spiracle is absent in Actinopterygii. 3. External nare is on the top of the head. 4. Caudal fins are either homocercal or heterocercal. 5. Endoskeleton is either bony or cartilaginous in Actinopterygi.
Why are ray finned fishes called Actinopterygii?
Actinopterygii. Actinopterygii ( /ˌæktɪˌnɒptəˈrɪdʒiaɪ/ ), or the ray-finned fishes, constitute a class or subclass of the bony fishes. The ray-finned fishes are so called because their fins are webs of skin supported by bony or horny spines (“rays”), as opposed to the fleshy, lobed fins that characterize the class Sarcopterygii…
How are actinopterygians classified into the subclasses?
Actinopterygians are divided into the subclasses Chondrostei and Neopterygii. The Neopterygii, in turn, are divided into the infraclasses Holostei and Teleostei. During the Mesozoic and Cenozoic the teleosts in particular diversified widely, and as a result, 96% of all known fish species are teleosts.
Which is part of the skeleton does the Actinopterygii attach to?
Actinopterygii. These actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connection between these fins and the internal skeleton (e.g., pelvic and pectoral girdles).
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