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Frequenty Asked Questions

About Monkfish

Blackfin goosefish
Blackfin goosefish
Lophius gastrophysus

  Monkfish Monkfish being measured Basket full of monkfish Cheif Scientist, R. Anne Richards, Ph.D.Monkfish to be measured
1. What are the various names for monkfish?
The 'official' common name for monkfish is American goosefish; however, the market name is monkfish and this is widely used. Other common names are allmouth, molligut and fishing frog. The scientific (Latin) name for monkfish is Lophius americanus.
2. How many species of monkfish occur in the North Atlantic?
In the western North Atlantic there are three species of monkfish (goosefish): 

American goosefish = Lophius americanus
reticulate goosefish = Lophius reticulatus
blackfin goosefish = Lophius gastrophysus

In the eastern North Atlantic, there are two commercial monkfish species:

Lophius piscatoris
Lophius budegassa

3. What is the maximum size of monkfish?
Bigelow and Schroeder (in Fishes of the Gulf of Maine, published 1953) observed the maximum size of monkfish (goosefish) to be four feet (122 cm).  They noted that the fish may reach six feet in length but there are no documented measurements to verify this.  The largest fish taken in NMFS surveys was 138 cm (54 inches), taken in Cape Cod Bay in the autumn of 1978.  The second longest fish documented from a survey was 135 cm (53 inches), caught in Massachusetts Bay by State of Massachusetts inshore surveys in 1979.  Nine additional fish 121 cm or greater in length have been taken in NMFS surveys.  Most of these very large fish were taken in the Gulf of Maine or Southern New England waters and all were caught prior to 1987.
4. What is the maximum age of monkfish?
The maximum age of monkfish is not known at present.  The largest monkfish which have been aged by the Northeast Fisheries Science Center were 98 cm (age 8), 95 cm (age 8) and 91 cm (age 9).   This suggests fish approaching 140 cm could be 13 or 14 years old, or even older depending on how growth rates slow with age. 
5. How is the age of monkfish determined?
The age of monkfish is determined by counting marks that can be seen on the vertebrae, much like rings are counted on fish scales or on tree stumps.  Vertebra number 8 is dissected from the vertebral column and baked in a slow oven for several hours.  The baking helps define the rings by darkening protein bands within the vertebra.  The annual marks can then be counted with the aid of a dissecting microscope.
6. How fast do monkfish grow?
Monkfish grow about 10 cm per year, up to an age of around 90 cm.  Since we currently have ages for few fish larger than 90 cm, we cannot say how rapidly they grow after age 8 or 9 years.  Most vertebrate species grow more slowly or cease to grow as they reach maximum size or age.  Present data do not show major differences between growth rates of males and females, or between goosefish from the southern and northern management regions.
7. What do monkfish eat?
Monkfish are opportunistic feeders, which means they eat pretty much anything that comes their way, including soda cans and other trash. However, goosefish larger than about 20 cm (8 inches) feed primarily on fish, while smaller goosefish also rely on invertebrates such as shrimp.  The most important fish prey for small goosefish is sand lance (sand eels).  Monkfish have a reputation for being cannibals; however, there are relatively few documented cases of cannibalism.  When it does occur, cannibalism tends to be by larger fish (> 60 cm or 24 inches).


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