STAFF SURGEON, R. N.
At a time when so much attention is being paid to the West Indian Islands as regards their politics, social condition, and natural history it may not be out of place to briefly consider the subject of the poisonous fishes to be found in the neighboring seas. Considering the number of unwholesome fish abounding in these waters and the numerous cases of illness caused by them, I was surprised on investigation to find that so little appeared to be known or written on the subject. During my three-years' cruise in the West Indies the study of those fishes reputed to be poisonous was forced upon me by reason of the numerous cases of illness among the sailors of my own ship. When it is asserted that there are no less than sixty varieties of noxious fishes to be found in Cuban waters alone, it seems desirable that those who are about to settle in these parts should have some general idea as to what fish to choose and what to avoid.
Colored fishermen are not too particular about hawking unwholesome fish in the streets, even when its sale is forbidden in the market, and numerous cases have come under my notice where the unwary purchaser has paid the penalty by a sharp and painful illness. One of the great delights of our sailors is to land on some sandy beach, provided with a large seining net, in order to catch fish, the consumption of which varies the monotony of salt beef and pork. On examining the hauls they made I invariably found some unwholesome specimens, which I advised them to reject, and by so doing every time they went seining had no more cases of fish poisoning on board.
In tropical seas some fish are found to be always poisonous wherever and whenever caught, but there are numerous instances where wholesome fish become noxious when found in certain localities, especially on coral reefs and shoals. Fish when feeding on decomposing coral polyps, medusæ, and poisonous mollusks found on these reefs often become noxious, as the following instance will prove: Midway between Cuba, Hayti, and Jamaica lie the extensive reefs and shoals of the Formigas, which are several miles in extent and covered by a small depth of water. These shoals present a concentration of all the incidents to be found in West Indian fringing shore reefs. Arborescent corals and spreading millepores stretch on walls and ledges, interspersed with huge meandrinas and brainstones, among which lodge a profusion of Holothurias, starfishes, and a variety of sponges. This great mass of reefs, called from their clustering swarm the Ants' Nest, or the Formigas, abound with all sorts of fishes. As you approach the great submarine plateau, the odor of the slime and of the spermatic substances that find a resting place in the crevices and shallow pools spread through it is very remarkable—the pleasant blandness of the sea breeze suddenly changing to the nauseating smell of a fish market. Those who have waded on tropical shore reefs know not only the strong scent given out by the polyps that build there, but feel how sensibly the hands are affected, and how the skin of the thighs is susceptible of a stinging irritation from the slightest contact with the slime of corals. It has been found by invariable experience that all the fishes taken on the Formigas are pernicious; that the barracudas especially are always poisonous. Similar stretches of shoals among the Bahamas produce fishes deleterious as food.
The low-spreading ledges and banks of the Virgin Islands, called the Anegadas, or the Drowned Islands, afford a similar unfavorable ground for fishing. In this way we may account for the remark of Dr. Grainger that fishes are poisonous at one end of St. Christopher while they are harmless at another. We get over, by these several incidents of those fishing grounds, the adventitious occurrence of poisonous among wholesome fishes, which become deleterious from the food on which they subsist at certain seasons on certain banks and coasts.
Again, in the tropics wholesome fish soon become virulently poisonous if kept too long, as the fierce heat favors rapid decomposition. In this short article I have only space for a description of the most common and injurious fishes met with in the West Indies. One of the commonest fish in these seas is the barracuda (Sphyræna barracuda), which can be easily recognized by its elongated body, covered with cycloid scales. The color is dark olive-green on the back, fading to a lighter green on the sides, while its under surface is silvery white. The mouth is wide and curved, with long and sharp teeth. These fishes are large and voracious, often attaining the length of six feet; and as they are usually found close inshore, amid the heaviest surf, they are as much feared by fishermen and bathers as the shark. Indeed, they are more to be feared, for the shark as a rule is timid, and unless extremely hungry is cautious in its voracity. The barracuda, on the contrary, is very bold. The shark flees from a splashing in the water, but the barracuda goes there to see what he may find, as he is only attracted by live bait. The wounds inflicted by the barracuda are exceedingly severe and sometimes fatal.
When young this fish is generally used as food, but having attained a certain size the flesh becomes exceedingly noxious, at least at certain seasons of the year. This change is said to be due to the poisonous fish on which they feed. When caught on certain banks, as the Formigas, their flesh is always extremely unwholesome, and, as Kingsley says, they have this advantage, that while they can always eat you, you can not often eat them with impunity. The Cubans, as a rule, will not touch this fish, and at Santa Cruz it is the custom never to eat it till the next day, and then not till after salting it; but that is apparently no safeguard, as four persons living in Kingston, Jamaica, suffered severely after eating "corned barracuda."
It is stated that when unwholesome, its teeth will be found of a blackened color at the base, and on inserting a silver coin into its flesh this will also turn black. The poisonous symptoms caused by this fish are peculiar, and were strongly marked in the case of a friend of mine who was a solicitor living in Barbados. He and several others who had partaken of the same fish suffered from severe gastro-intestinal disorder, with intense nausea and vomiting. His face swelled up and became tubercular like a leper; afterward, general muscular tremblings and acute pain about the body, particularly in the joints of his hands and arms, came on. The nails of his feet and hands became black and fell off without any pain, and his hair also fell out. For years after he suffered from debility and tubercular skin eruptions. Death sometimes follows, but those who do not die suffer for a long time from its effects, which in some cases last for twenty-five years.
The "yellow-tailed sprat" (Clupea thrissa) is common in the West Indies, and may be recognized by having its last dorsal ray prolonged into a filament. A black spot behind the gill cover is said to distinguish it from a somewhat similar fish, the "red-eared pilchard," which has a yellow spot behind its gill cover. Schomburgk gives testimony to the poisonous properties of the "yellow-tailed sprat" when found at certain periods of the year among the Leeward and Virgin Islands.
The eating of this poisonous "sprat" is said to be followed by most violent symptoms and rapid death. The common saying in the West Indies—that if you begin at the head you never have time to finish the tail—is almost literally true.