POISONOUS FISH. 
§ 650 .] 
497 
The action of the poison on animals consists in a rapid paralysing 
effect on certain regions of the central nervous system, first the respira¬ 
tory centre and then the vaso-motor centre being attacked ; at the same 
time a curarin-like paralysis of the peripheral ends of the motor nerves 
is observed, which in frogs may be very complete. The heart is not 
affected directly, and continues to beat after the cessation of the 
respiration. The blood-pressure sinks on account of the paralysis 
of the vaso-motor centre. The symptoms in man are similar to those in 
animals, and may be gathered from the following account of a typical 
case recorded by Takahashi and Inoko. 
A man in Kinshin (Japan), at 2 p.m., ate five pieces of a Tetrodon 
(species not known). Four hours afterwards he complained of an uneasy 
feeling in the epigastrium ; the pulse at that time was normal. Vomit¬ 
ing was excited by tickling the back of the throat. Quite suddenly the 
patient was incapable of walking, and he was soon completely paralysed. 
Motion of the tongue was difficult, and his speech was indistinct. Later, 
cyanosis, diminished frequency of breathing, and dilatation of the pupil 
were observed. The corneal reflex disappeared, and the body tempera¬ 
ture sank. Artificial respiration and injection of camphor and strychnine 
gave no relief, and death quietly followed five hours after the meal. 
Neither in animals nor in man are the post-mortem appearances 
distinctive. 
§ 650. Other Poisonous Fish. —Some fishes are poisonous on account 
of the food they live upon : the Meletta venenosa is only poisonous when 
it feeds upon a certain green monad ; Clupea thrissa, C. venenosa , and 
certain species of Scarus possess neither poison glands nor poisonous 
ovaries, but also derive their poisonous properties from their food. 
In the West Indies it is well known that fish caught off certain coral 
banks are unwholesome, while the same species caught elsewhere may be 
eaten with safety. 
A good many shell-fish, especially mussels, occasionally cause intense 
poisonous symptoms ; those usually noticed are high fever, nettle-rash, 
dilated pupils, and diarrhoea. It may be that in these cases a toxine, 
the product of bacterial action, has been ingested. To the agency of 
bacteria has been ascribed illness produced in Russia by a good many 
fish of the sturgeon species. The symptoms are those of cerebro-spinal 
paralysis. The “ Icthyismus gastricus ” of Germany may belong to the 
same type. Prochorow 1 has described illness from ingestion of Petro- 
myzon fluviatilis in Russia. Whether the fish was eaten raw or cooked, 
the effect was the same, producing a violent diarrhoea, dysenteric in 
character. Even the broth in which the fish had been boiled produced 
symptoms. Fresh blood of the eel is stated to be intensely poisonous ; 
this property is apparently due to a toxalbumin ; Pennavaria 2 relates 
1 Pharmac. Ztg., 1885. 2 11 Farmacista Italiano, xii., 1888. 
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