414 
Fishery Bulletin 106(4) 
Size-frequency distributions for larvae from inshore and offshore zones of the Coral Sea 
of Thunnus alalunga (albacore) during the (A) early November, and (B) late November 
cruises, and for Auxis-Euthynnus during the (C) early February cruise. Standard length 
(mm) of larvae was measured to the nearest 0.1 mm. P-values refer to the significance 
of Kolmogorov-Smirnov (K-S) tests conducted between the inshore and offshore zones 
within a cruise. 
near-reef (within 2 km offshore) distributions of Mak- 
aira indica (black marlin), M. mazara (blue marlin), 
and Istiophorus platypterus (Indo-Pacific sailfish) larvae 
in the Coral Sea (“the anstau hypothesis,” Leis et ah, 
1987). The istiophorid larvae examined by Leis et al. 
(1987) for horizontal distributions were taken from the 
same samples used in this study. Like billfish, larvae of 
Thunnus spp. also have relatively shallow distributions; 
greatest abundances were found in the upper 20 m of 
the water column around Oahu Island (Boehlert and 
Mundy, 1994) and higher concentrations were found at 
5 m depth than at 10 m depth in French Polynesia (Leis 
et al., 1991). Larvae of T. atlanticus (blackfin tuna) 
were caught in greatest numbers in the upper 20 m of 
the water column in the northern Caribbean Sea, and 
few larvae were caught below 40 m depth (Hare et ah, 
2001). We cannot confirm this hypothesis, however, 
because we did not take direct measurements of either 
currents or the vertical distributions of tuna larvae 
during the present study period. 
Downwelling on the seaward side of the outer reefs in 
the Coral Sea could account for the simultaneous occur- 
rence of opposing on-offshore distributions of K. pelamis 
and Thunnus larvae because of known differences in 
the vertical distributions of larvae between these two 
genera. Larvae of K. pelamis have deeper distributions 
