The Sting
Posted by martin braun on August 31, 2005
Q: I remember from a course on Zoological anatomy that there is at least one type of ray-finned fish that lives among or near the tentacles of stinging jellyfish and also has the ability to swallow an entire nematocyst which then,(almost right out of a comic book or child's or primitive human idea of the passing of traits by consuming them), is able to have the nematocyst leave the animal's digestive system and to become part of the fish's own defensive arsenal. It's as though one could swallow a gun and, the next day, have a working firearm as part of one's anatomy!
Do you know what this process is called and what the fish species is?
A: You have a good memory. The fish you're referring to is one of the Driftfishes called the Man-o-War fish (Nomeus gronovii). These fish are almost always found in association with the stinging jellyfish called the Man-o-War (Physalia physalia). This is a commensal relationship in which one of two organisms benefits by its association without harming or helping the other. Of course, in this relationship, the fish gains protection from the stinging tentacles although it too can be killed if not careful. Here are a couple of websites to help out too. Thanks for asking.
John Wiessinger ( August 31, 2005)