64 
PACIFIC SCIENCE, Vol. XII, January, 1958 
right and left with their bills, before turning 
back and leisurely picking up those they have 
killed or crippled.” Another report by these 
authors (p 136) was that: "Marlin were every- 
where, scattering bait and cutting the water 
with their fins and tails .... Terrified patches 
of bait skittered across the water endeavoring 
to elude their pursuers who slashed relent- 
lessly.” 
Voss (1956) has contributed the following 
information. "How well the sailfish uses this 
weapon I discovered one calm winter day off 
Stuart, Florida, when we backed our boat into 
a school feeding on minnows. The sailfish 
circled slowly, sails half raised, herding their 
prey tighter and tighter. First one and then 
another broke from the circle and swam 
through the milling prey, thrashing right and 
left with their bills. Then the predators would 
submerge and lazily eat the dead and stunned 
minnows as they drifted down.” 
It is, of course, possible that a difference 
exists in the method of capturing trolled baits 
and free-swimming prey, even though the 
spearfishes may be facile in each method. 
One must give complete credence to such 
observations as made by Voss. It is evident 
that on occasion, abnormal though it may 
be, the spear is used to obtain food by thrash- 
ing. However, the mass of observations in- 
dicate this to be a rather infrequently em- 
ployed method. The following observations 
from the field and from studies of stomach 
contents shed considerable light on the matter. 
In examining the stomach contents of many 
marlin, the author has at times noted that the 
heads and pectoral regions of some of the less 
digested specimens had been severely dam- 
aged on both sides, presumably as a result of 
having been crushed between jaws. Along 
the same line Thomas and Thomas (op. cit ., 
p. 124) stated that "the bills [upper and lower 
jaws] of a marlin leave two distinct depressions 
on a small fish just behind the gills.” These 
observations indicate that, at least at times, 
the struggling prey is seized so as to kill it, 
or to hold it firmly preparatory to swallowing 
it. The observations also indicate that in such 
situations the spear is not used to obtain food. 
If the prey had been killed or stunned or so 
injured as to prevent escape the marlin would 
not have needed to crush the prey before 
swallowing it. 
That marlin can feed without the use of the 
spear is demonstrated by the following state- 
ment by Miss Francesca LaMonte of the In- 
ternational Game Fish Association (quoted 
by Hubbs and Wisner, 1953): "Dr. D. G. 
Maitland of Sydney, Australia, has recently 
written us as follows: 'It may interest you to 
know that I have actually watched a pair of 
Black Marlin feeding upon Physalia , like huge 
Rainbow Trout taking flies, and absolutely 
ignoring a most tempting looking mackerel 
bait drifting in front of their noses.’ ” 
That prey much larger than the small coe- 
lenterate of the genus Physalia may be cap- 
tured without obvious use of the spear is 
indicated by another observation. During pre- 
liminary studies of the food of striped marlin 
in the San Diego area in 1952, a young blue 
shark, Prionace glauca (Linnaeus), a little 
longer than 24 inches, was found in the 
stomach of a 205-pound marlin. This shark, 
which had been recently ingested bore no 
marks of a blow or thrust of the spear. A 
roughening of its skin over rather broad areas 
could have been produced by the sandpapery 
jaws of the marlin as it grasped and held the 
struggling shark. A blow, or blows, of suffi- 
cient force to kill or stun the notoriously 
hard-to-subdue shark would almost certainly 
have left identifiable marks on the body. 
Still another indication of feeding that cer- 
tainly would not call for use of the spear was 
encountered by the author while examining 
striped marlin stomach contents at Mazatlan, 
Sinaloa, Mexico, in March, 1954. Both marlin 
and sailfish were feeding on a species of 
argonaut. Such a relatively slow-moving mol- 
lusk would be as easily captured as Physalia 
and would require not even the lightest tap 
from a spear. 
