Key Characteristics:
- Roughly equal number pre and post-anal myomeres.
- Fewer total myomeres than Percidae (less than 35).
- Double dorsal fin, but this may not be visible until they are older.
- Dorsal and anal fins across from each other.
- Deep-bodied
- Can have many or few melanophores.
![Caption](https://blog.uwgb.edu/ais/files/2018/05/MKE_0011.jpg)
Larval Rock Bass. 7 mm. United States Fish Wildlife Service. Milwaukee Harbor, WI. Ashley Smith. 2017.
![Caption](https://blog.uwgb.edu/ais/files/2018/05/LT_003.jpg)
Multiple Larval Rock Basses. Between 7 mm – 8 mm. Green Bay, WI. Ashley Smith. 2017.
![Caption](https://blog.uwgb.edu/ais/files/2018/05/GRBY0035.jpg)
Larval Rock Bass. 12.2 mm. United States Fish Wildlife Service. Green Bay, WI. Marian Shaffer. 2017.
![Caption](https://blog.uwgb.edu/ais/files/2018/05/0043.jpg)
Juvenile Rock Bass. 32.5 mm. United States Fish Wildlife Service. Green Bay, WI. Adam Dziewa. 2018.
- Body not elongated, eel-shaped, round in transverse section, uniformly pigmented (1B)
- Chin barbels absent (3B)
- Snout short, its length usually less than 10% TL; median fins otherwise (5B)
- Median fins or finfolds showing distinct separation (7B)
- No adipose fin, or demarcation of one, in finfold (10B)
- Preanal myomeres greater than or equal to postanal myomeres (14A)
- Preanal myomeres approximately equal to postanal myomeres (difference five myomeres or less) (15A)
- Total myomeres less than 35 (20B)
- Total myomeres between 26 and 34 (21B)
- Adipose fin or its position absent (23B)
- Double Dorsal Fin (24A)
- (Centrarchidae)
Adult History
- Physical Description
- Largemouth extends to the eye, dark gill spot, dark spots on each scale, overall bronze appearance, red eye, dorsal fin has two lobes (first spine: 10-12 spines & second: 10-12 rays), anal fin has 5-7 spines and 9-11 rays, and 39-43 ctenoid lateral scales
- Spawning Habitat
- Shallow water along the shores near aquatic vegetation
- Lakes & streams
- Shallow water along the shores near aquatic vegetation
- Spawning Substrate
- Eggs are deposited over gravel or sand
- Spawning Behavior
- Polygynandry Behavior
- Nesting activity takes place at water temperature of 53 – 61°F
- Males build nests for spawning
- Male circles the nest awaiting the female
- Males guard the nest after their eggs are fertilized
- Females will either go mate again or stays around their original breeding spot
- Time of Year
- May – July in Lake Michigan
- Spawning typically takes place at water temperatures of 60 – 70°F
- Diet
- Piscivore – crayfish, aquatic insects, and small fish