106 



Fishery Bulletin 104(1) 



Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Jul Sep Nov 



1997 



1998 



1999 



Figure 3 



Cumulative number of species collected in both tidal-creek and seagrass 

 habitats (open circles) and number of species collected in tidal-creeks 

 (trianglesi and seagrass habitats (filled circles) by year and month 

 from January 1997 to December 1999. 



Fish fauna 



At the conclusion of the three-year study, 111 fish species 

 and 4 additional species complexes had been collected. 

 During the first year of the study, 61 species were col- 

 lected in samples taken in tidal-creek habitats, and 

 48 species were collected in seagrass habitats (Fig. 3). 

 Thirteen new species were added to the species list from 

 tidal creek samples and 20 new species were added to 

 the list from samples taken in seagrass habitats during 

 1998. During the final year of sampling only six addi- 

 tional species were collected in tidal creeks and 12 new 

 species were collected in seagrass habitats. Overall, tidal 

 creeks contained greater relative (uncorrected for gear 

 efficiency) densities offish (3.89 fish/m'-) compared with 

 seagrass habitats (0.93 fish per m-). In seagrass habi- 

 tats, 15,395 individuals were collected in 118 samples 

 that covered approximately 16,520 m- of seagrass habi- 

 tat (Table 1). In tidal-creek habitats, a total of 76,176 

 individuals were collected from 288 samples that covered 

 approximately 19,584 m- of tidal-creek shoreline habitat 

 (Table 2). Thirty five species were restricted to seagrass 

 habitats, and another 35 species were collected only in 

 tidal creeks. The remaining 45 species were collected 

 in both habitats at least once during the study. Overall, 

 twelve families were restricted to seagrass habitats: 

 phycid hakes (Phycidae), toadfishes (Batrachiodidae), 

 batfishes (Ogcocephalidae), flyingfishes (Exocoetidae), 

 cardinalfishes (Apogonidae), barracudas (Sphyraenidae), 

 wrasses (Labridae), combtooth blennies (Blenniidae), 

 mackerels (Scombridae), triggerfishes (Balistidae), box- 

 fishes (Ostraciidae), and porcupinefishes (Diodontidae; 

 Table 1). Seven families were restricted to tidal-creek 

 habitats: minnows (Cyprinidae), sunfishes (Centrarchi- 

 dae), killifishes (Cyprinodontidae), gars (Lepisosteidae), 



eagle rays (Myliobatidae), pikes (Esocidae), and livebear- 

 ers (Poeciliidae; Table 2). 



Fish assemblages 



A clear separation of fish assemblages was identified 

 and indicated by two main branches that corresponded 

 to fishes found in seagrass habitats and those found in 

 tidal-creek habitats (Fig. 4). There were two months iden- 

 tified from seagrass samples (January 1997 and March 

 1998) that had a species composition that was more 

 closely linked to samples taken from tidal creeks. 



Seagrass habitats 



Seasonal fish assemblages in seagrass habitats were evi- 

 dent during all three years of the study, which included 

 winter-spring, summer, and fall assemblages (Fig. 4). 

 The winter-spring assemblage consisted principally 

 of pinfish {Lagodon rhomboides). pigfish (Orthopris- 

 tis chrysoptera). dusky pipefish (Syngnathus floridae), 

 southern puffer (Sphoeroides nepheliis), and gulf pipe- 

 fish [Syngnathus scovelU). which together accounted for 

 more than 95% of the cumulative percent similarity. The 

 summer assemblage had a higher average similarity 

 value (43.67) than did the winter-spring assemblage 

 (42.56) and consisted of more than 21 species. Eleven 

 of these species — silver perch (Bairdiella chrysoura), 

 S. floridae, bay anchovy {Anchoa mitchilli), L. rhom- 

 boides, Eucinostomus spp., spotted seatrout (Cynoscion 

 nebulosus), S. scovelli, planehead filefish (Monacanthiis 

 hispidus), striped anchovy {Anchoa hepsetus). inshore liz- 

 ardfish {Synodus foetens), and O. chrysoptera — accounted 

 for more than 75% of the cumulative similarity of the 

 summer assemblage. The fall assemblage had the high- 



