January 6, 2012
Fish Mimics Fish-Mimicking Octopus
A good eye will spot the black-marble jawfish next to the mimic octopus's arm (Credit: Godehard Kopp)
The mimic octopus (Thaumoctopus mimicus) has the uncanny ability to make itself look like more dangerous creatures, such as lionfish, sea snakes and soles. The octopus does this with its distinctive color pattern and ability to adjust its shape and behavior (see this earlier blog post on the octopus for a video in which it mimics a flatfish). But now the mimic has a mimicker of its own, scientists report in the journal Coral Reefs.
Godehard Kopp of the University of Gottingen in Germany was filming a mimic octopus during a diving trip to Indonesia last July when he spotted a companion–a small fish that followed the octopus for several minutes, always sticking close to the octopus’s arms. Kopp has some good observational skills, because the fish’s color and banding looks incredibly similar to that of the octopus.
Kopp sent his video (see below) to two marine scientists at the California Academy of Sciences who identified the fish as a black-marble jawfish (Stalix cf. histrio). The three write:
Jawfish are poor swimmers and usually spend their entire adult lives very close to burrows in the sand, to where they quickly retreat, tail first, upon sight of any potential predator….[In Kopp's video and photos], the Black-Marble Jawfish seems to have found a safe way to move around in the open. The Mimic Octopus looks so much like its poisonous models that it is relatively safe from predation, even when swimming in the open, and by mimicking the octopus’ arms, the Jawfish seems to also gain protection.
This might at first glance appear to be a case in which the fish evolved its coloring to gain protection by associating with the octopus, but the scientists don’t think that’s likely. The jawfish can be found from Japan to Australia, but the octopus lives only in the region around Indonesia and Malaysia. They contend that this is a case of “opportunistic mimicry,” in which the fish is taking advantage of a happy coincidence.
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So these marine scientists are suggesting that the black-marble jawfish knows what it looks like?
Editor: Please check the validity of the creditals of the so-called marine scientists. They don’t seem to know the difference between “venomous” and “poisonous”. Other than that, the discovery points out the intricate relationship of most or all of God’s plants and animals.
Mahajohn, any organism that needs to visually recognize members of its own species will have knowledge of what a member of its own species looks like, and thus what it itself looks like. This is not necessarily awareness (or even “knowledge” strictly speaking) per se, but it allows the organism to make surprisingly informed decisions that depend critically on what it itself looks like, which, as you say, it can never truly know.
The same question that John Grunwell raises also occurred to me. I doubt that the fish has the capacity to reason that it looks like the octopus, no more than a North American Viceroy butterfly knows that it resembles a monarch butterfly. The butterfly survives because of this happy accident.
It seems more plausible that the black-marble jawfish knows on some level what its species looks like, and was seeking company.
According to the Merriam Webster dictionary, one of the definitions of knowledge is the fact or condition of being aware of something. Another definition is the fact or condition of knowing something with familiarity gained through experience or association
Either of these definitions could apply since the fish seems to be aware that traveling with the octopus gives it some protection. This awareness could have been gained through experience.
Keep in mind that the instinct to survive exists in all creatures & therefore learning to blend into the surroundings would be part of that. After all, they can see.
It would be also be foolish to judge a fish’s ability to reason by human standards, since fish are not human.