LEIS ET AL.: DISTRIBUTION AND ABUNDANCE OF BILLFISH LARVE 



Table 1. — Distribution of istiophorid larvae based on transects from the Great Barrier Reef Lagoon into tfie Coral 

 Sea. Co, concentration (larvae'1,000 m3); Ab, abundance (larvae/100 m^); f, frequency (i.e., nunnber of positive hauls). 

 Values for Co and Ab are medians, and parenthetically, ranges. P is for Kruskal-Wallis test. For tested data sets, values 

 with the same superscript symbol (# or t) are not significantly different (P > o.05, SNK Test). NT, not tested statistically: 

 T, because only 2 samples were taken in block A; F, because too few larvae were taken. Normally, 6 samples were taken 

 in each block on each cruise. No larvae were taken on the cruises not listed. 



may have a distribution similar to that of blue 

 marlin and black marlin larvae (Table 1). 



Sizes of Larvae From 

 Bongo Net Tows 



Black marlin larvae ranged from 2.5 to 6.8 mm 

 with a strong mode at 2.8-2.9 mm (Table 2a). 

 Statistical comparison of the size-frequency data 

 between areas could only be undertaken for the 

 first cruise. Data from block A were compared 

 with data from all other areas pooled. The size- 

 frequency distributions were possibly different 



(Kolmogorov-Smirnov test, P = 0.07): a greater 

 proportion of the larvae were of the smaller size 

 classes (<4 mm) in block A than in the other 

 blocks. Inspection of the limited size-frequency 

 data from the other cruises indicates a similar 

 situation. More than one cohort of larvae was 

 present because larvae on the second cruise were 

 not larger than those on the first. 



Blue marlin larvae ranged from 2.5 to 8.3 mm 

 with a weak mode at 3.1 mm (Table 2b). Too few 

 blue marlin larvae were captured to allow rigor- 

 ous analysis of the size-frequency data, but there 

 did not appear to be any difference in the size 



761 



