296 
PACIFIC SCIENCE, Vol. XV, April 1961 
to reveal any ducts owing to excessive tissue 
damage. 
Ova diameter measurements revealed that the 
posterior ovarian section of gonad A and both 
ovarian segments of gonad B were identical in 
their degree of development. The ova ranged 
from small, primitive ova to larger, opaque ova. 
Average diameters of 25 randomly selected ova 
of the most advanced group were 0.479 mm. 
for the posterior ovarian section of gonad A 
and 0.476 mm. and 0.479 mm. for the anterior 
and posterior ovarian sections, respectively, of 
gonad B. 
The development of the anterior ovarian sec- 
tion of gonad A was dissimilar to any of the 
sections previously examined. Its lumen con- 
tained a loose mass of large, ripe, resorbing 
ova, together with a few completely degenerated 
ova. The peripheral portion of the section con- 
tained only primitive ova. Those intermediate 
to the primitive and the large, resorbing ova 
were absent. 
The presence of residual ova indicates that 
this fish also had been a functional female. 
Again, it is not clear whether the ova remnants 
were the unexpelled portions of a previous suc- 
cessful spawning or a group of ripe ova that 
were not expelled owing to the inadequacy of 
the duct. Damage to the posterior portions of 
both gonads made it impossible to determine 
whether the male ducts were connected to the 
exterior, but since the testicular segments were 
well developed, this fish may also have been a 
functional male. 
Hermaphroditism in skipjack is an extremely 
rare occurrence. So far as is known, only one 
other example has been recorded and described 
(Nakamura, H., 1935, Trans. Nat. Hist. Soc. 
Formosa 25(141): 197-198; in Japanese). 
