Okaloosa darters usually are found in water 

 from 0.15 to 0.61 m deep (Collette and Yerger 

 1962) associated with clumps of bulrushes and 

 bur-reed {Sparganium americanum) where cover 

 and protection are sought (Yerger 1979). They do 

 not occur in impoundments (ODRT 1977). 



Habitat photographs may be found in Crit- 

 tenden (1974) and Mettee et al. (1976). 



FOOD AND FORAGING BEHAVIOR 



Not known. 



SHELTER REQUIREMENTS 



Not known. 



NESTING OR BEDDING 



Green algae clumps are used as egg-attach- 

 ment sites during spawning (Collette and Yerger 

 1962). For water depth and flow requirements 

 see Reproduction. 



RITUAL REQUIREMENTS 



Not known. 



OTHER CRITICAL ENVIRONMENTAL 

 REQUIREMENTS 



Nothing is known of territoriality or home 

 range size in this species. Relationships with the 

 brown darter are discussed under Reasons For 

 Current Status. 



Cool, running water is one requirement, and 

 eutrophication has an undesirable effect (Crit- 

 tenden 1974). 



It is possible that severe rainfall with associ- 

 ated flooding may affect the distribution in 

 streams at least temporarily (R. W. Britte personal 

 communication ) . 



POPULATION NUMBERS AND TRENDS 



Estimates of population size range from 1,500 

 to 10,000 individuals with the true figure proba- 

 bly falling somewhere in between (Yerger 1976). 

 Mettee (1976) estimates between 1,500 and 

 2,000 individuals. 



Population levels may have been only slightly 

 reduced in the past 15 years except in areas (parts 

 of Rocky and Swift Creeks) where the brown 

 darter has been introduced. Here the numbers of 

 Okaloosa darters have been reduced, probably 

 due to competition with sibling species (Yerger 

 1979). 



REPRODUCTION 



Spawning was observed in Tom's Creek on 25 

 March 1961 in sv«ft water 0.30 to 0.46m deep 

 over a sandy bottom at the edge of clumps of 

 green algae. Several eggs were deposited individu- 

 ally in the algae and one egg hatched on 27 March 

 in the laboratory (Collette and Yerger 1962). 



On 25 March 1961, several mature adults 

 were placed in aquaria with green algae; on 1 April 

 1961, six eggs were discovered individually 

 attached to the algae (Collette and Yerger 1962). 



Nothing is known of longevity or survival 

 rates. 



MANAGEMENT AND CONSERVATION 



Yerger (1979) suggests that field studies be 

 conducted to determine the species population 

 status and details of interaction between the Oka- 

 loosa and brown darters as well as to monitor the 

 spread of the latter species. He also suggests 

 potential methods for controlling or eliminating 

 introduced brown darters by physical removal. He 

 suggests that this be done while populations are 

 small and either before spawning has begun or 

 long after it is over. Okaloosa darters would be 

 returned to the water after the operation is com- 

 pleted. Removal should be conducted annually. 



Crittenden (1974) suggests that no new 

 impoundments be constructed on any of the Oka- 

 loosa darter drainages. If determined necessary, 

 they should be small and at the extreme head 

 waters of the tributaries. Measures should be 

 taken to prevent excessive siltation. Suggestions 

 include constructing roads at oblique angles to 

 streams, maintaining water breaks, and seeding of 

 road banks as soon as possible. The use of pesti- 

 cides and fertilizers in this drainage area should be 

 exercised with great caution. 



A Recovery Team has been formed and a 

 draft Recovery Plan submitted to the U.S. Fish 

 and Wildlife Service for review. The draft plan 

 calls for studies to determine the optimum habi- 

 tat for Okaloosa darters, normal population levels 

 and fluctuations, and potential hazards to the 

 species' continued existence. The plan also out- 

 lines actions that could be taken if the results of 

 research indicate a potential extirpation. These 

 actions include defining permissible and prohib- 

 ited activities, land acquisition, creating more 

 optimum habitat, transplanting, and reducing 

 populations of competitors or predators (ODRP 

 1977). 



