Better Left in the Ocean – Blue Spot Jawfish


The bluespot jawfish (Opistognathus rosenblatti) is a stunningly beautiful jawfish, but it suffers from very poor survivability in the home aquarium.

The bluespot jawfish, also called blue spotted jawfish and a few other variations, is typically found on the eastern coast of the Pacific Ocean, and in particular the Gulf of California (Sea of Cortez). The waters in this area are somewhat cooler than waters where most tropical fish are collected, and the bluespot jawfish is typically found at deeper depths. Understanding these two aspects of their habitat is critical to provide the proper aquarium environment for them to thrive. But since most reef aquariums hover in the 78-80 degree Fahrenheit range (and sometimes up to 84 degrees), these fish become stressed and more susceptible to diseases and parasites.

Blue Spot Jawfish

Blue Spot Jawfish

© 2009 Foster & Smith, Inc. Reprinted as a courtesy and with permission from

The two diseases that affect the bluespot jawfish the most frequently in my experience are brooklynella (typically associated with clownfish) and the mysterious Blue Spot Jawfish Disease. If a blue spot is infected with brooklynella, there is really no hope left for it. The fish will quickly deteriorate and die withing 24 hours or less. The jawfish will show signs of peeling skin and color loss all over its body, and it will refuse to eat. It may or may not wander around the aquarium, but it will most certainly leave its burrow and die. It is very painful to watch as there is virtually nothing you can do to save it at this point.

As for their diet, this jawfish (and others) readily eats in most saltwater aquariums and is not too picky about what it is being fed. However, individuals can be easily scared back into their burrow my more aggressive eaters. If you have aggressive fish in your tank, the jawfish may not come out to eat or may not get enough food.

Blue Spot Jawfish

Blue Spot Jawfish

Photo Provided by the Author

Lastly, blue spot jawfish are extremely poor shippers. They just can’t handle the stresses as effectively as other fish can. It’s not unusual to have several fish show up dead on arrival (DOA) to a fish store. It’s also pretty common for the remaining few survivors to die overnight or within the following few days.

The bluespot jawfish, like the other fish on our “Better Left in the Ocean” series can be successfully kept in an aquarium. But like the others, these fish require pristine water conditions and an advanced hobbyist who knows how to treat various diseases and troubleshoot problems that might occur since immediate and responsible action is usually required.

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