Worms in rockfish

B

bythesea

Member
Joined
Nov 15, 2010
Messages
235
Location
florence
I've been catching a lot of rock fish lately,which is great.but what's up with the worms? Is it just a little added protein or what? I need a good answer soon cause my wife's going to find out sooner or later and well,need I say any more. thanks.
 
G

GraphiteZen

Well-known member
Joined
Mar 21, 2008
Messages
2,157
Location
Corvallis, Oregon
The "worms" are actually parasites, and you don't want to mess with parasites............ Note that they are large organisms that have burrowed into the flesh of an animal.
 
B

BobbiDollPDX

1
Joined
Feb 2, 2010
Messages
644
Location
Milwaukie, Oregon
Worms in rockfish
--------------------------------------------------------------------------------
All living organisms, including fish, can have parasites. Parasites are a natural occurrence, not contamination. They are as common in fish as insects are in fruits and vegetables. Parasites do not present a health concern in thoroughly cooked fish.
Parasites become a concern when consumers eat raw or lightly preserved fish such as sashimi, sushi, ceviche, and gravlax. When preparing these products, use commercially frozen fish. Alternatively, freeze the fish to an internal temperature of -4°F for at least 7 days to kill any parasites that may be present. Home freezers may not be cold enough to kill the parasites.

The health risk from parasites is far less than the risk from "unseen" illness causing bacteria which are present on almost all foods. Here are some commonly asked questions about fish parasites.


What are the worms that I sometimes see in fish I catch or buy?Roundworms called nematodes are the most common parasite found in marine fishes. Some people call these nematodes herring worms or cod worms. Actually, several different species exist and it is hard to distinguish between them. All are in the family Anisakidae and are anisakid nematodes.
Freshwater fish like trout and fish that spend part of their life in freshwater such as salmon may carry Diphyllobothrium tapeworm larvae. These small, whitish, and somewhat flabby worms are common in salmon from some areas of Alaska.


How do fish get parasites?The life cycle of an anisakid nematode begins when seals or sea lions eat infected fish (Figure 1). The larval nematodes grow to maturity, and the marine mammal excretes the nematode eggs into the sea where they hatch. Shrimp-like animals eat the larvae, and fish eat the shrimp-like animals. The larvae then develop into the form we see in fish.
The life cycle for a tapeworm is similar. Mammals or birds eat infected fish. The eggs hatch in freshwater. Crustaceans eat the eggs, freshwater and anadromous fish eat the crustaceans, and we eat the fish.



Will parasites hurt me if I accidentally eat one?Nematodes rarely cause health problems because they are uncommon in fish fillets and normal cooking easily destroys them. In most cases, swallowing a live nematode is harmless. The nematode passes through the intestine without causing problems.
In rare cases, swallowing a live nematode larva can cause severe gastric upset called anisakiasis. This happens when the nematode attaches to or penetrates the intestinal lining. Nematodes do not find humans to be suitable hosts and will not live longer than 7-10 days in human digestive tracts.

Swallowing live tapeworm larvae can cause a tapeworm infestation. The tapeworms may live in the human intestinal tract for several years. Symptoms can include abdominal pain, weakness, weight loss and anemia. Doctors successfully treat tapeworm infections with medicines.


How long should I cook fish to kill parasites?Cooking fish to an internal temperature of 140°F will kill all fish nematodes and tapeworms. Normal cooking procedures generally exceed this temperature.

How about smoking, pickling, and salting fish?Heating hot-smoked fish to an internal temperature of at least 140°F will kill all fish nematodes and tapeworms. Normal hot-smoking procedures generally exceed this temperature.
Dry-salting fish, or curing them in a saturated salt brine, for 5-7 days before pickling will kill nematodes and tapeworms. Pickling without salt curing may not destroy some nematodes.


Are raw and lightly marinated recipes safe?Eating raw fish, just like eating raw meat or poultry, is riskier than eating cooked products. To minimize the risk, avoid eating raw or lightly marinated seafood unless the fish is free of parasites, or has been properly frozen.
It is a common practice to use frozen fish in countries where raw fish dishes are traditional. Japan's National Health Institute recommends freezing fish to -4°F for several hours when preparing raw fish, or avoiding fish that are susceptible to parasites.

Canada's Health Protection Branch recommends using only commercially frozen fish in raw fish dishes because home freezers will not kill the parasites. The U.S. Food and Drug Administration recommends using fish frozen commercially for 7 days at -10°F or 15 hours at -31°F for raw fish dishes.


Why don't processors remove parasites from fish?Good handling practices on-board fishing vessels and in processing plants minimize nematode infestation. Many seafood processors inspect seafood fillets of species likely to contain parasites. This process called candling involves examining fish fillets over lights. Candling detects surface parasites. Unfortunately, they cannot always see parasites embedded deep in thick fillets or in dark tissue.

What can consumers do if they find a worm in fish?If a parasite is present in a fish, you have several options:

•Remove the parasite, examine the fish for others and cook the fish. Thorough cooking kills all parasites
•Notify the store where you bought the fish so that the store can carefully inspect remaining fish.
•Depending on the return policy of the particular store, you may wish to return or exchange the unused portion.


The authors are Robert J. Price, Ph.D., Seafood Technology Specialist, and Pamela D. Tom, Staff Research Associate, Department of Food Science & Technology, University of California, Davis, California 95616-8598
This leaflet is based in part on "Parasites in marine fishes, questions and answers for seafood retailers," Publication SG 79/Reprinted October 1985, Oregon State University Extension Service, Oregon State University, Corvallis, Oregon, by Kenneth S. Hilderbrand, Robert J. Price, and Robert E. Olson.

UCSGEP 90-7 August 1990

This work is sponsored in part by NOAA, National Sea Grant College Program, Department of Commerce, under grant number NA89AA-D-SG138, project number A/EA-1, through the California Sea Grant College Program, and in part by the California State Resources Agency. The U.S. Government may reproduce and distribute reprints for governmental purposes.
 
B

bythesea

Member
Joined
Nov 15, 2010
Messages
235
Location
florence
Well I ask for a good answer. what more could I ask for. oh ya, and I'll be having parasites for dinner. Thanks for getting that Info me!!
 
C

CoastieFlo

Member
Joined
Nov 22, 2010
Messages
223
Location
Florence mainly...but wherever the fish are too!
Thats a GREAT post on worms, sums in up very nicely.

As a former fishmonger for a major chain store, I can tell you there is worms in store bought fish also........it happens, its nature. Pick em out if you see them, and cook it up.....no worries. A little tapeworm friend might help me keep the pounds off anyway :)
 
S

slabjig

New member
Joined
Aug 30, 2007
Messages
9
I've been catching a lot of rock fish lately,which is great.but what's up with the worms? Is it just a little added protein or what? I need a good answer soon cause my wife's going to find out sooner or later and well,need I say any more. thanks.
It's pretty easy to check for worms in your fillets, just hold them up to a light and look for dark spots (usually coiled up) in the fillets. Insert the tip of your fillet knife in the center of the coil and pop them out. After I fillet a batch of rockfish at the coast, I bring them home and "candle" them for parasites while I'm removing the little row of intramuscular bones that are hard to get out on a stainless fillet table. Voila, boneless parasite free fillets. It's odd that some days, you seem to catch quite a few fish with parasites, other days very few. It also seems to relate to size, bigger ones (presumbly older and with more time to be exposed to the intermediate hosts) seem to have more. Might be an argument for not keeping the biggest fish (which are also the ones who produce the most offspring). And don't think it's just rockfish, they are pretty common in ling cod and greenling too. Another hint while you're at it, when you catch a rockfish (or any bottomfish)...cut a gill before you throw it in a cooler with an ice bottle. Iced bled fish make for snowy white fillets that taste better and have more eye appeal.
 
G

GraphiteZen

Well-known member
Joined
Mar 21, 2008
Messages
2,157
Location
Corvallis, Oregon
I was also told to gut the fish as you catch them as this prevents whatever parasites that are in the digestive tract from going into the tissue after the fish dies.
 
G

GraphiteZen

Well-known member
Joined
Mar 21, 2008
Messages
2,157
Location
Corvallis, Oregon
Ok. Well. I was going to post some roundworm surgery vids from Youtube. Now I'm not. And I may never eat sushi again...
 
H

halibuthitman

1
Joined
Feb 12, 2009
Messages
3,052
Location
on the edge
Its quite easy to remove them, just go buy a blue or black light bulb and mount it about 2 feet above a white cutting board, turn off the main lights and turn on your set-up and have your hemostats ready.. all the worms will show right up... you also can avoid the worms by not eating the belly meat.
 
Top Bottom