Needle Fish with Lesions

Observation: Needle fish (stickleback) - (Cukilget in the Yupik language) were found with lesions on them after been caught and brought back from fishing. They had to look for ones like this because most of the fish were fine. My cousin got them the day before or two days before the pictures were taken. They were caught with dip nets about four bends up from the mouth on the Kinia River. My Aunt Nellie showed me the pictures. Other people also said they saw these bumps on needle fish. When people found them like that, they wanted to throw them back in the river or feed them to the dogs. Needle fish are a subsistence food. Some people eat them frozen and dipped in seal oil. They are also mashed and the sharp tips taken off, so as to be included in soup. They are small fish about as big as a finger. We fish for these during the winter through a hole in the ice. There were two elders who said they have seen fish with skin bumps like this once before. They ate them before and did not get sick. But people are still worried because they are not sure what it is this time. We have seen black bumps before in other fish, but these bumps in the stickle back were like puss. There are quite a few people who are worried about this. Because we eat them and because we want to know what is wrong with the fish. Kimberly Abraham

Alaska Department of Fish and Game Consult: According to Ted Meyers, ADF&G Pathology Lab, an assessment was provided to Jolene John on these fish, as described by in this email correspondence shared by ADF&G: "The white and mucoid lesions are really a hallmark feature of Glugea or other similar parasite infections. These would be cysts that contain the organism. Glugea (Glugea anomala) other fish microsporidians do not represent a human health concern. However just as with any fish, proper preparation should be used if intended for human consumption because they may contain other parasites or infectious agents that are not as noticeable."

Ted Meyers adds, "Glugea is fairly common in some fish species and like many parasites their abundance and occurrence at any given time or within a single fish population can be influenced by the interaction of several host and environmental factors that defy a specific explanation."

LEO says: There is some research suggesting a seasonal relationship with Glugea anomala in stickleback. Higher rates in female fish were documented during spring and summer because of reproductive activities and water temperature. (Source: Morozińska-Gogol J)

Resource:

Food and Drug Administration, offer the following guidance on controlling parasites in fish: The process of heating raw fish sufficiently to kill bacterial pathogens is also sufficient to kill parasites. The standard recommended cooking temperature is 140 F (60° C).The effectiveness of freezing to kill parasites depends on several factors, including the temperature of the freezing process, the length of time needed to freeze the fish tissue, the length of time the fish is held frozen, the fat content of the fish, and the type of parasite present. The temperature of the freezing process, the length of time the fish is held frozen, and the type of parasite appear to be the most important factors. For example, tapeworms are more susceptible to freezing than are roundworms. Flukes appear to be more resistant than roundworms.Freezing and storing at -4°F (-20°C) or below for 7 days (total time), or freezing at -31°F (-35°C) or below until solid and storing at -31°F (-35°C) or below for 15 hours, or freezing at -31°F (-35°C) or below until solid and storing at -4°F (-20°C) or below for 24 hours is sufficient to kill parasites. (FDA’s) current thinking on this topic.