Table 3.- 



FISHERY BULLETIN: VOL. 84, NO. 4 



-Comparison of five most abundant taxa from neritic waters off Louisiana with ichthyoplankton surveys 



throughout the Gulf of Mexico. 



1 1nshore data only. 



2 1977 bongo net data only. 



surface waters of his offshore transect (Table 



2). 



Offshore, Houde et al. (1979) found that clupeids 

 (Spanish sardine and Atlantic thread herring), 

 gobiids, and bothids (mostly dusky flounder, Sya- 

 cium papillosum) dominated summer ichthyoplank- 

 ton in the eastern Gulf of Mexico off Florida, where- 

 as clupeids (round herring and Spanish sardine), 

 bothids (mostly gray flounder, Etropus rimosus), 

 and bregmacerotids dominated the winter. In the 

 western Gulf of Mexico off the south Texas coast, 

 Finucane et al. (1979) reported that, during 1977, 

 clupeids (mostly scaled sardine) and bothids (most- 

 ly Syacium spp.) dominated the summer and breg- 

 macerotids and clupeids (menhaden) the winter 

 ichthyoplankton. In the northern Gulf of Mexico off 

 Louisiana, Ditty and Truesdale (1984) found that 

 engraulids and carangids (mostly Atlantic bumper) 

 dominated the summer (July 1976), whereas larvae 

 of clupeids (mostly gulf menhaden) and gobiids 

 dominated the winter (January-February 1976). The 

 most abundant families collected overall off Florida 

 were clupeids and gobiids (35.6% of all larvae), and 

 off south Texas were gobiids and synodontids 

 (26.7% of all larvae). The kinds of larvae (gobiids, 

 bothids, clupeids, and bregmacerotids) that domi- 

 nated these two offshore surveys were similar, but 



with clupeids and bothids relatively more abundant 

 off Florida than Texas; engraulids were relatively 

 more abundant off south Texas than off Florida 

 (Table 2). Ditty and Truesdale (1984) found clupeids 

 and engraulids most abundant overall (67.7% of all 

 larvae), but their surveys were too limited temporal- 

 ly and in areal coverage for adequate comparison 

 to the other two offshore surveys. 



The 10 most abundant families accounted for 

 66.6% of all larvae collected off Florida (Houde et 

 al. 1979) and for 68.6% off south Texas (Finucane 

 et al. 1979). In contrast, the top 10 families in each 

 of the coastal surveys contributed over 90% of all 

 larvae collected. Likewise, the five most abundant 

 taxa contributed over 80% of all larvae collected in 

 all but one (Collins and Finucane 1984) of the coastal 

 surveys but <40% in the two offshore surveys (Table 

 3). 



In conclusion, there was general agreement 

 among all three coastal surveys from the north- 

 central Gulf of Mexico on peak seasonal occurrence 

 of many of the abundant taxa and on the dominant 

 families in overall larval abundance. Comparison of 

 other coastal and offshore ichthyoplankton surveys 

 throughout the Gulf of Mexico with the present 

 study suggests that, when compared with offshore 

 waters, there are relatively fewer dominant taxa 



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