from resting under ledges (angelfish 

 and butterflyfish) to the trigger 

 and filefish, and trunkfishes which 

 are active and in the open, probably 

 feeding. 



Bottom feeding primary and 

 secondary carnivores include certain 

 damselfishes, wrasses, angelfishes, 

 and butterfly-fishes. Plankton 



feeders of the sea bass or grouper 

 (Serranidae) , damselfish, and wrass 

 families, are diurnal and inactive 

 at night. Nocturnal plankton feed- 

 ers commonly include the cardinal- 

 fish ( Apogonidae) , sweeper (Pempher- 

 idae), grunt (Pomadasyidae) , herring 

 (Clupiidae), and silverside (Ather- 

 inidae) families. The latter three 

 families have species which also 

 feed diurnally on plankton. 



Many of the nocturnal feeders 

 prey, to a large extent, on inver- 

 tebrates. These include members of 

 the whiptail stingray (Dasyatidae) , 

 squirrel and soldierfish (Holocen- 

 tridae), sea bass, snapper (Lut- 

 janidae), grunts, drum, croaker 

 (Sciaenidae) , and porcupinefish 

 (Diodontidae) families. All feed in 

 the day when food is readily avail- 

 able and frequently do so under 

 natural conditions. The exclusively 

 diurnal feeding members of these 

 families usually feed on species 

 quite different from those of their 

 nocturnal relatives. 



The larger carnivores, includ- 

 ing various sharks (Carcharhinidae 

 and Sphyrnidae), morays (Muraen- 

 idae), groupers, jacks, scads, pom- 

 panos (Carangidae) , and barracudas 

 (Sphyraenidae) , are crepuscular, 

 feeding most actively at dawn and 

 dusk. However, these fish are also 

 opportunistic and will feed anytime 

 food is available. 



Timing of the feeding behavior 

 of the fish fauna reflects the 

 availability of food. For example. 



since sessile organisms such as 

 plants, epizooites, and larger, 

 fixed animals form a source of food 

 which cannot hide, they are commonly 

 preyed upon by diurnally feeding 

 fish. Planktonic feeders are either 

 nocturnal or diurnal in response to 

 the constant available food source. 

 It is interesting to note that these 

 fish are either diurnal or nocturnal 

 but seldom both, suggesting a dis- 

 tinct partitioning of resource uti- 

 lization by day and night feeding 

 species. Since many non-sessile 



reef invertebrates are nocturnal, 

 so are their predators. Large car- 

 nivores, as mentioned previously, 

 feed whenever food is available but 

 most intensively during the twilight 

 hours, presumably to take advantage 

 of the higher concentrations of 

 unsheltered organisms. Table 44 and 

 Figure 62 summarize the fish fauna 

 commonly associated with various 

 habitats of the Florida Keys marine 

 environment (Table 44) and their 

 distribution (Figure 62) for day and 

 night hours. 



Numerous studies, other than 

 those discussed above, have addres- 

 sed various aspects of the Florida 

 Keys fish fauna. Starck (1968) 



makes reference to 37 publications 

 that had dealt with fishes from 

 Alligator Reef. A later work by 

 Starck and Schroeder (1971) examines 

 the biology of one of the more com- 

 mon fishes of this environment, the 

 grey snapper ( Lutjanus qriseus ). 

 Because the grey snapper's life 

 cycle intertwines with several of 

 the more diverse marine habitats 

 (mangrove, seagrass, coral reef) 

 this study is of added importance to 

 the understanding of total marine 

 ecosystem. Zieman (1982), Odum et 

 al. (1982) and Jaap (1982) review 

 the role of fish fauna in the sea- 

 grass, mangrove, and coral reef 

 habitats, respectively, of the Flor- 

 ida Keys. Randall (1967) describes 

 the food habits of over 200 species 



212 



