Marlin Harms, California USA, California, USA
Info
The butterfish Apodichthys fucorum initially resembles an eel-like animal with its elongated body shape with reduced or absent paired fins.
This fish has the same color as the sea lettuce (Ulva) in which and on which it lives, the little guy is even able to breathe out of the water for a time, but this also puts it at risk of being preyed upon as an appetizer morsel by hungry seabirds.
The Bay Area Underwater Explorers site (baue.org) features specimens of this species with a uniform red-brown coloration.
It is understandable that these color morphs would have virtually no chance of survival in green seaweed, so the question arises, can the animals match their color to their environment? Answer: No!
Studies on the coloration of butterfishes lead to the assumption that the coloration of the animals depends on two factors:
First, the fish instinctively "recognize" the color of the algae that matches the body coloration of the fish; second, the amphipods that the fish eat seem to have a corresponding influence on the coloration.
The same seems to be true for the algae species and their usual water depth:
Green algae are found in the shallow zones, then there are brown algae, and red algae the deepest (their pigment can best absorb the blue-green light that can penetrate to greater depths).
According to research, if a butterfish larva started feeding on amphipods that are well adapted to green algae, it would be colored green as a result.
A scientific experiment showed the following about this:
Fish larvae from green and reddish-brown animals were equally fed Artemia nauplii, and all animals took on the typical reddish coloration.
These findings come from the exciting website "The Marine Detectives" https://themarinedetective.com/2021/04/19/gunnel-gunnel-gone/.
Gunnels, as they are called in English, are colorful little fish that live exclusively in tidal and underwater waters, and some species can even be found at low tide, hidden among the seaweed waiting for the water to return.
These fish can be a delight for divers and photographers alike because of their color and unique markings.
Synonym: Xererpes fucorum (Jordan & Gilbert, 1880)
This fish has the same color as the sea lettuce (Ulva) in which and on which it lives, the little guy is even able to breathe out of the water for a time, but this also puts it at risk of being preyed upon as an appetizer morsel by hungry seabirds.
The Bay Area Underwater Explorers site (baue.org) features specimens of this species with a uniform red-brown coloration.
It is understandable that these color morphs would have virtually no chance of survival in green seaweed, so the question arises, can the animals match their color to their environment? Answer: No!
Studies on the coloration of butterfishes lead to the assumption that the coloration of the animals depends on two factors:
First, the fish instinctively "recognize" the color of the algae that matches the body coloration of the fish; second, the amphipods that the fish eat seem to have a corresponding influence on the coloration.
The same seems to be true for the algae species and their usual water depth:
Green algae are found in the shallow zones, then there are brown algae, and red algae the deepest (their pigment can best absorb the blue-green light that can penetrate to greater depths).
According to research, if a butterfish larva started feeding on amphipods that are well adapted to green algae, it would be colored green as a result.
A scientific experiment showed the following about this:
Fish larvae from green and reddish-brown animals were equally fed Artemia nauplii, and all animals took on the typical reddish coloration.
These findings come from the exciting website "The Marine Detectives" https://themarinedetective.com/2021/04/19/gunnel-gunnel-gone/.
Gunnels, as they are called in English, are colorful little fish that live exclusively in tidal and underwater waters, and some species can even be found at low tide, hidden among the seaweed waiting for the water to return.
These fish can be a delight for divers and photographers alike because of their color and unique markings.
Synonym: Xererpes fucorum (Jordan & Gilbert, 1880)
