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PACIFIC SCIENCE, VoL XV, April 1961 
manini were tagged and held in a tank at Coco- 
nut Island. Within 3 weeks the tags were no 
longer present on the fish. They were recovered 
from the bottom of the tank with the loops of 
nylon intact, thus indicating that the nylon had 
pulled through the flesh. 
The same type of tag was then threaded 
through the upper part of the hypural plate of 
the 2 fish. As they swam, the tag of each oscil- 
lated slightly as it was drawn along in a position 
just above the caudal fin. Three months later 
both tags were in place, and the method looked 
auspicious. On March 3, 1953, while operating 
from the fishing vessel "Friendly Isle’’ owned 
by Samuel Kaolulo, 50 adult manini were tagged 
in this manner. Two fish were recovered 5 
days later, both in the vicinity of the point of 
release. No other recoveries were reported. The 
two Coconut Island manini lost their tags be- 
fore 6 months elapsed, and further plans for 
tagging by this method were abandoned. Dis- 
appointing results with Atkins tags have been 
reported by other authors, such as Fraser (1955). 
Petersen disk tags were then tried. Since 
stainless steel seemed most promising among the 
Fig. 20. Petersen disk tag used in tagging Acan- 
thurus triostegus sandvicensis on Oahu. The ends of 
the monofilament nylon connecting the disks have 
been melted into knobs with a cigarette lighter. The 
heating caused a blackening of the one knob which is 
visible. 
metals commonly used to attach these tags ( Cal- 
houn, Fry, and Hughes, 1951), this material 
was chosen for initial trials. Considerable dif- 
ficulty was experienced, however, in bending the 
free ends of the wire on a struggling fish, a dis- 
advantage clearly pointed out by Calhoun et al. 
Attention was then shifted to nonmetallic sub- 
stances, of which nylon seemed the most propi- 
tious. It is superior to metal in its pliability, non- 
toxicity, and in not being subject to electrolytic 
action or fatigue. In order to keep the disks in 
place, the ends were melted into knobs with a 
flame (Fig. 20) . The position of the tag on the 
fish is shown in Figure 21. (For a detailed dis- 
cussion of this tagging method, see Randall, 
195 6a.) 
On August 6, 1953, 3 captive adult manini 
were tagged with plastic disks by 60-lb. test 
monofilament nylon (diameter, 1 mm.) and 1 
with stainless steel wire. 
Seven weeks after tagging, all 4 fish, along 
with 6 untagged fish which were measured at 
the time the 4 fish were tagged, were caught 
and remeasured. The 6 untagged fish, which had 
a mean standard length of 86.3 mm., had grown 
an average of 6.6 mm. The 3 tagged with nylon 
(mean standard length, 84.4 mm.) grew an av- 
erage of 7.7 mm. The 93 mm. fish whose disks 
were attached with stainless steel wire added 
the smallest increment of growth, 2.5 mm. Al- 
though there are insufficient data for definite 
conclusions, it seems apparent that manini 
tagged with Petersen disk tags fastened with 
monofilament nylon are capable of normal 
growth. 
One of the fish which survived 11 months 
until July when the tank was needed for other 
purposes still retained its disks fastened with 
nylon. It was noted that the tagging wound was 
small, and there was no evidence of deteriora- 
tion of the nylon. 
Since the experimental tagging demonstrated 
no obvious fault in this method, field tagging 
was begun. Forty-five manini were tagged with 
hand-made tags. This proved to be most time 
consuming, and assistance was requested of and 
granted by the Hawaii Division of Fish and 
Game. Manufactured tags of laminated cellulose 
acetate (Fig. 20) were purchased. In order to 
publicize the tagging, posters (Fig. 21) were 
