416 
of alga. They say that their fish became toxic 
when this alga, which they had not seen before, 
began to grow on the now toxic reef. This alga, 
a blue-green Schizothrix calciola (Agardh) Go- 
mont, 3 grows on top of fine algae already grow- 
ing on the reef (see section on Marakei) . If this 
alga should be associated with toxic conditions, 
then this upholds Randall’s hypothesis (1958) 
that a fine, blue-green alga might be one of the 
basic causes of toxicity in fishes. 
Many Gilbertese believe that certain people 
are immune to fish poison, and many even eat 
a toxic fish without harm. It is commonly said 
that there have been occasions when a family 
group has partaken of a large fish, and some of 
them have been severely poisoned, others not 
at all. However, neither the amount of fish nor 
the parts eaten are taken into consideration. A 
little-known belief which still lingers, especially 
among the older people, is that of family totem 
fishes. It is almost impossible to find out very 
much about this belief, as the Gilbertese are 
very loathe to talk about it. When discussing 
toxic fish with Gilbertese it should be realized 
that some older people still consider that certain 
families may be magically affected by certain 
species of fish. 
Some Gilbertese think that the toxin is con- 
centrated in the liver and guts of a fish, and that 
the viscera may be toxic when the flesh is not. 
This idea has been confirmed by Halstead and 
Bunker (1954). Other Gilbertese think that 
the toxin is concentrated in the blood, and that 
if the throat, guts, and large blood vessels are 
ripped from a still living Lutianus bohar then 
that fish will be safe to eat. Banner et al. (1963) 
report that large specimens of Lutianus bohar 
killed, filleted, and frozen within half an hour 
of catching proved just as toxic as specimens 
kept for several hours after death. In spite of 
these ideas the Gilbertese do not usually bother 
to clean or gut carnivorous or small fish before 
cooking them. It is considered a waste of time 
to gut such fish as Lutianus bohar or species of 
Muraenidae, as the Gilbertese say the guts are 
too small to bother about. It is customary, how- 
3 This alga, originally identified as Fleet on ema tere- 
brans (Bornet and Flahault) by Dr. Franci Drouet, 
has been assigned to the above species by Drouet. See 
Drouet, 1963, Ecophenes of Schizothrix calciola , Proc. 
Acad. Nat. Sci. Phila. 115(9) : 261— 281 . 
PACIFIC SCIENCE, Vol. XVIII, October 1964 
ever, to clean and gut certain herbivorous fish 
such as Mugil spp. or Kyphosus sp. 
Randall (1958) mentions that if a person 
who is recovering from an attack of ciguatera 
poisoning eats a reef fish he may experience a 
return of certain symptoms. He suggests that 
therefore the fish must contain toxin at a level 
sufficient to raise the toxin in the eater to the 
threshold level, but not sufficient to affect 
people who have not been recently poisoned. 
The Gilbertese people agree with this conten- 
tion, but maintain that all fish will accentuate 
the neurologic symptoms in someone who is 
recovering from ciguatera poisoning, including 
species that have never been known to cause 
ciguatera, for instance flying fish. 
The Gilbertese have the usual superstitions, 
proved false by Banner et al. (1963), that flies 
will never settle on a toxic fish, that a silver coin 
will turn black if it is cooked with a toxic fish, 
and, one superstition that appears to be peculiar 
to the Gilbertese, that grated coconut will turn 
bright green if baked inside a toxic fish. A more 
promising method of testing for a toxic fish oc- 
casionally practiced is to give one of the house- 
hold cats a sizable piece of the suspect fish; if 
the cat is not ill in a few hours then the fish 
is not toxic. Another, probably more frequent 
"test,” is for one of the family to act as guinea 
pig and eat some of the fish, although this is not 
considered foolproof because people react dif- 
ferently to the toxin. It is customary in toxic 
areas for old people to eat part of a large fish 
first. Later, if no symptoms of poisoning de- 
velop, the rest of the family will finish the fish. 
Experienced residents of toxic areas never allow 
their children to eat doubtful or uncommon fish 
until several hours, preferably a night, after it 
has been tried by the older members of the 
family. 
This custom makes most puzzling the state- 
ment of Cavallo and Bouder (1961) and of 
Bouder et al. (1962) that ciguatera poisoning 
was a primary cause of infant mortality on Syd- 
ney Island (which the author visited in 1953). 
Sydney Island, in the Phoenix group, had no 
indigenous population prior to 1939, when it 
was settled by Gilbertese from the southern Gil- 
berts, but had at times been worked for guano 
and copra. It is a most unfertile, drought-stricken 
atoll, the enclosed lagoon being too salty to sup- 
