1. What traits that the ostariophysans have, which made this group so successful?

2. Ostariophysians
This diverse group contains almost 8,000 species, about 28% of known fish species in the world and 68% of freshwater species, and are present on all major continents except Antarctica.
NO Ostariophysians

3. Gonorynchiformes

4. Cypriniformes

5. Characiformes

6. Catfish This group（Ostariophysians
） includes a wide variety of different fishes. It contains one of the largest freshwater fish ever caught, the Mekong giant catfish, which can weigh up to about 300 kg. It also contains the smallest species of freshwater fish, Danionella translucida at only 12 mm in length.

7. Gymnotiformes

8. Two Unique Traits
The alarm response
The Weberian apparatus

9. The alarm response
The alarm response involves : the production of an alarm substance; and a behavioral alarm reaction to the presence of the substance in the water.

10. The alarm response
When the fish is injured, this pheromone is released; other fish of the same species or similar species can smell this pheromone, causing a fright reaction. However, some fish possess the alarm substance without the fright reaction or lack both the alarm substance and the fright reaction to the alarm substance.

11. The alarm response

12. The Weberian apparatus
It is made up of a set of bones known as Weberian ossicles, a chain of small bones that connect the auditory system to the gas bladder of fishes. The ossicles connect the gas bladder wall with Y-shaped lymph sinus that abuts the lymph-filled transverse canal joining the sacculi of the right and left ears. This allows the transmission of vibrations to the inner ear.

13. The Weberian apparatus
The structure acts as an amplifier of sound waves that would otherwise be only slightly perceivable by the inner ear structure alone. With the added function of the swim bladder as a resonating chamber, signals are amplified to noticeable levels
water
bladder
W.A
Inner ear

14. or which made this group so successful? The alarm response
The Weberian apparatus

15. The Weberian Apparatus
Apart from this structure(The Weberian apparatus), there is no other trait that could explain the success of otophysians

16. Sensitivity is similar to neuromodulation and humoral regulation.
灵敏度类似于神经调节与体液调节
The upper hearing frequency limit of the other order ： 2000~3000
非骨鳔总目听觉频率上限：2000~3000
The upper hearing frequency limit of the Ostariophysians ： 7000~10000
骨鳔总目听觉频率上限：7000~10000

17. The presence of the structure is one of the most important and phylogenetically significant distinguishing characteristics of the Ostariophysi.
O s t a r i o p h y s a(i)
Small bone
A bladder

18. thanks