Observations on the 
Toxic Sea Anemone, Rbodactis howesii (Coelenterata) 
Edgar J. Martin 1 
The sea anemone. Rbodactis howesii W. S. 
Kent 1893 belongs to the phylum Coelenterata, 
order Corallimorpharia, family Actinodiscidae. 
This animal occurs on reefs in tropical areas 
of the Pacific Ocean (Cutress, 1957). The pres- 
ent study was done with specimens from the 
reefs of the Samoa Islands. American Samoans 
call R. howesii "matamalu” and attribute a 
form of fatal poisoning to either suicidal or 
inadvertent ingestion of the raw sea anemone. 
Such cases have repeatedly been mentioned by 
local medical authorities. However, cooking in 
water destroys the poison and cooked "mata- 
malu” is commonly eaten by the natives. 
While on a tour of duty at the Hospital of 
American Samoa, the author observed three 
cases of this poisoning. Shortly after the alleged 
ingestion of the sea anemone the patients went 
into stupor which lasted from 8 to 36 hours, 
depending on the case. During this period, knee 
jerk and pupillary light reflexes were absent but 
blood pressure and pulse rate were normal. All 
patients finally went into prolonged shock. They 
died with pulmonary edema. The clinical history 
and course of the poisonings recalled paralytic 
shellfish poisoning (Meyer, 1928). The phase 
of stupor suggested that the poison had either 
a curare-like action or affected primarily the 
central nervous system. The long duration of 
this phase suggested that the poison was differ- 
ent from known paralytic marine poisons and 
that it would be worthwhile to investigate it. 
The paucity of research facilities on the is- 
lands restricted us to a study of general prop- 
erties of the poison. We hoped that informa- 
tion so obtained would be adequate for both 
comparing this poison with other "marine poi- 
sons” and studying the conditions of preserva- 
1 Formerly with the Department of Medical Services 
of the Government of American Samoa, Pago Pago, 
American Samoa. Present address : 7 Edmund Avenue, 
Toronto, Ontario, Canada. Manuscript received March 
17, 1959. 
tion under which the highly perishable sea 
anemone could be shipped overseas to research 
laboratories with its poison intact. A bio-assay 
had to be worked out, using what was avail- 
able. Various snails and fishes and the toad 
Bufo tnarinus L. (Oliver, 1953) 2 were tried. 
All showed some response to the poison, but 
that of B. marinus was the most suitable for a 
bio-assay. When the toads were injected with 
homogenates of sea anemone their survival time 
showed a definite relation to the injected dose. 
METHODS 
The toads were captured the evening before 
the experiments. From the time of their capture 
till the end of the observations they were given 
no food and were kept moist in darkness at an 
environmental temperature of 25-30° C. Four- 
teen to 16 hours after capture the toads were 
weighed and injected intraperitoneally with 
homogenates, five toads being used at each dose 
level. After injection each toad was turned over 
on its back at intervals, and its alertness and 
ability to return to normal posture were noted. 
The toads showed no change in behavior and 
reactions for several hours after injection. Then, 
suddenly, their responsiveness to change in 
posture and their mean frequency of respiration 
decreased, and within the following half-hour 
to 2 hours they died. In most of the toads the 
parotoid glands turned white immediately be- 
fore or as death occurred. 
For the bio-assay whole sea anemones were 
homogenized in an Osterizer with 4 times their 
volume of distilled water and then were further 
diluted with 0.9 per cent NaCl solution for 
easier handling. In assays with "fresh” sea 
anemones the time elapsed from the harvesting 
of a batch on the reef until the last injection 
of its homogenate into the toads was 4-6 hours. 
2 Bufo marinus was introduced on Tutuila, Amer- 
ican Samoa, by D. H. Butchart in 1951 (Butchart, 
1957), and presently abounds on that island. 
403 
