Review of Clupeotoxism, an Often Fatal Illness from the Consumption of Clupeoid Fishes

Poisoning from eating clupeoid fishes such as sardines and herrings (Clupeidae) or anchovies (Engaulidae), termed clupeotoxism, is widespread in tropical and subtropical areas of the world but rare. A fatal case occurred in Kaua‘i in 1978 from the consumption of the Marquesan Sardine (Sardinella marquesensis). This species has been replaced in abundance in the Hawaiian Islands by another import, the Goldspot Sardine (Herklotsichthys quadrimaculatus). Onuma et al. (1999) obtained the head of a specimen of this sardine that caused a fatality in Madagascar and found that it contained palytoxin. Because bottom sediment was detected on the gills and in the esophagus, they concluded that the fish is a bottom-feeder, and the benthic dinoflagellate Ostreopsis siamensis, known to produce palytoxin, the toxic organism. The sediment on the gills was more likely the result of the fish being dragged over the substratum by a seine. The Goldspot Sardine feeds on zooplankton, not benthic organisms. Therefore, a pelagic dinoflagellate is the probable producer of palytoxin. The consumption of certain tropical marine fishes, even though well cooked, may result in severe illness and even death. Halstead and Lively (1954) separated such poisonings into four groups, ciguatera, tetraodon poisoning, gymnothorax (moray eel) poisoning, and scombroid (tuna) poisoning. In a review of ciguatera, Randall (1958) pointed out that gymnothorax poisoning is severe ciguatera, and scombroid poisoning is usually food poisoning (unrefrigerated tunas and bonitos spoil quickly by bacterial action). He briefly mentioned other valid categories of toxemia from eating fishes, including one resulting from ingestion of ‘‘certain tropical clupeid fishes,’’ later called clupeoid poisoning or clupeotoxism. Halstead (1967) reviewed cases of clupeotoxism, the first by Desportes (1770) from eating a sardinelike fish known as Clupea thryssa (1⁄4 the thread herring Opisthonems oglinum) at what is now the Dominican Republic. Oldendorp (1777) claimed that sprat (a general English common name for a clupeid) is the most poisonous fish in the Virgin Islands, adding that it is toxic only in circumscribed areas and at certain times of the year. Halstead (1967:610) listed 87 references dealing with clupeoid poisoning. He concluded with the following statement, ‘‘It is noteworthy that to date no one has reported any experimental work on the toxicology, pharmacology, or chemistry of these violently poisonous fishes. Apparently clupeiform fishes, which are generally valuable food fishes, become toxic only at sporadic intervals. The biotoxicity of these fishes appears to be a completely unpredictable phenomenon.’’ Halstead (1978:492) gave the symptoms of clupeoid poisoning as follows: ‘‘The first indication of a biotoxication is the sharp metallic taste which may be present immediately upon ingestion of the fish. This is soon followed by nausea, dryness of the mouth, vomiting, malaise, abdominal pain, and diarrhea. The gastro-intestinal upset may be accompanied by a feeble pulse, tachycardia, chills, cold clammy skin, vertigo, a drop in blood Pacific Science (2005), vol. 59, no. 1:73–77 : 2005 by University of Hawai‘i Press All rights reserved 1 Manuscript accepted 7 April 2004. 2 Bishop Museum, 1525 Bernice Street, Honolulu, Hawai‘i 96817-2704 (e-mail: [email protected]). pressure, cyanosis and other evidences of vascular collapse. Within a very short period of time, or concurrently, a variety of neurological disturbances rapidly ensue such as nervousness, dilated pupils, violent headaches, numbness, tingling, hypersalivation, muscular cramps, respiratory distress, progressive muscular paralysis, convulsions, coma and death. Death may occur in less than 15 minutes. Fergusen (1823) claimed that the poison was so rapid in its action that natives have died while in the very act of eating the yellow-billed sprat. . . .’’ Melton et al. (1984) reported on the death of a fisherman on Kaua‘i from eating three Marquesan Sardines (Sardinella marquesensis) in 1978. I (second author of the paper) identified the fish from skeletal remains obtained from the family of the deceased. This species was introduced to O‘ahu from Nuku Hiva, Marquesas, as a tuna baitfish between 1955 and 1959 during seven cruises of the research vessel Hugh M. Smith. In late 1958 small individuals were found, indicating that the species had become established. The sardine never became abundant enough to be of value as a baitfish, and it has not been reported in recent years. A second sardine, the Goldspot Sardine (Herklotsichthys quadrimaculatus), was first noticed in Kāne‘ohe Bay, O‘ahu, in 1975, becoming abundant in the bay the following year. Figure 1 illustrates a specimen from American Samoa. Williams and Clarke (1983) reported on its biology in O‘ahu, admitting that they first thought it was the Marquesan Sardine. The Goldspot Sardine may have entered Hawaiian waters in 1972 when the tuna-fishing vessel Anela dumped baitfish identified only as sardines on the return cruise from Jaluit, Marshall Islands, where the bait had been seined (Randall 1987). The Figure 1. Goldspot Sardine (Herklotsichthys quadrimaculatus), Tutuila, American Samoa. PACIFIC SCIENCE . January 2005 74