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PACIFIC SCIENCE, Vol. XII, January, 1958 
resulted from pugnacity, playfulness, or a 
desire to obtain food. The 157-pound tuna 
could conceivably have been regarded as an 
enemy by even a 1,500-pound marlin. The 
big dolphin would not seem to lit the enemy 
category although the relative sizes of prey 
and predator were not given. If it may be 
assumed that marlin customarily charge their 
prey to engulf it, it is then possible that the 
stabbings were accidental. If a spearfish is able 
to overtake its prey with sufficient speed to 
impale it, such speed should be more than 
adequate to permit the prey to be seized. 
Accidental stabbings of the smaller prey seem 
quite plausible if one considers the almost 
phenomenal accuracy required of the predator 
to hit and penetrate even an unsuspecting 
prey. In line with this view, impaling an 
evasive prey appears to be governed by 
chance. The few observations of stabbing 
make it seem possible that the spear may be 
used against the larger fishes — those not read- 
ily captured by overtaking and seizing be- 
tween jaws. 
The preponderance of evidence indicates 
the spear is not commonly used as a means 
of getting food. The food content studies to 
date have all dealt primarily with smaller for- 
age animals. Presumably few others have been 
found. One must conclude that these com- 
prise the bulk of the food of the spearfishes. 
As stated earlier, few indications of stabbing 
and none of injury by blows have been found. 
The prey had evidently been overtaken and 
engulfed by the predators. Those spearfish 
found with the spears missing had almost 
certainly employed this method of getting 
food. 
Examination of the spear and jaws indicates 
that the smaller forage fish and squid, the 
prime components of spearfish food, could 
not readily be stabbed. The spear is relatively 
dull at the tip and is covered by minute, 
sharp, backward-pointing nodules for its en- 
tire length. These nodules continue to each 
jaw, where they become a raspy band of teeth. 
The roughness of the spear covering is at- 
tested by fishermen who almost invariably 
wear gloves to avoid having their hands 
abraded while the fish are being boated. It 
would be difficult indeed for the dull tip to 
penetrate small fish. Certainly the soft, flex- 
ible body of a squid would be extremely diffi- 
cult to be impaled or to be dealt a damaging 
blow with so blunt a weapon. The swordfish 
has a smooth, laterally flattened sword of 
proportionately greater length than that of the 
spearfishes, but it is equally blunt at the tip. 
It is better suited as a flail but no better suited 
for spearing small prey. A striped marlin 
poorly suited for stabbing prey was observed 
by the author at Mazatlan, Mexico, 1954 
(Fig. 2). The curve of its spear was such that 
a thrust would tend to slide off a relatively 
small fish. 
Further evidence that the spearfishes do not 
commonly slash with their spears is found in 
their skeletal make-up. The construction is 
not suited to free and extensive sidewise mo- 
tion. The istiophorids have heavy, flat, plate- 
like neural and hemal spines rather than the 
common rodlike spines of other fishes. The 
neural processes are modified into broad 
platelike structures that extend far forward, 
almost reaching the middle of the preceding 
vertebra. The platelike hemal spines are 
firmly attached to the hemal processes of the 
neighboring vertebrae, as are the neural spines 
and processes. Such construction produces an 
exceptionally strong and inflexible, interlock- 
ing, bracing system. The vertebral column of 
the broadbill is less interlocked but is so 
fashioned as to resist greater shock from 
head-on encounters than is that of the spear- 
fishes. 
Nakamura (1938), who studied the skele- 
tons of many spearfishes, concluded that 
"The vertebrae are most unsuited for precise 
movements, and sudden changes of direction 
are probably impossible.” Furthermore, the 
deep and flat lateral surface of the anterior 
part of the body would require tremendous 
energy and leverage against the resistance of 
the water to accomplish a slashing movement 
