Most commonly recognized for being featured in the movie "Finding Nemo”, the clownfish is a marvel anemone species. We tend to generalize that clownfish are always orange with white stripes, however, of the 28 species of anemone fish, colors vary from red, black, pink, and yellow. Anemone fish are tropical, and commonly found in parts of Asia and Australia.
Anemone fish are unique in the fact that they have evolutionarily developed a symbiotic mutualistic relationship with sea anemone species. Sea anemones have modified cells that contain neurotoxins in specialized nematocyst cells; these cells, when touched upon the slightest contact, inject their venom into a host in response to self-defense or to capture food. However, the clownfish has mutually evolved with the sea anemone to avoid the sea anemone’s poisonous touch. How? According to this article, clownfish are understood to generate a protective mucous that acts as "chemical camouflage" preventing "not self" recognition by the sea anemone, thus inhibiting toxic nematocyst discharge into the fish. The symbiosis between these two organisms is unique. The sea anemone provides an array or resources for clownfish; clownfish utilize these organisms for shelter against predators, for egg protection, and as breeding and spawning grounds. When the sea anemone makes a kill, the clownfish also gains from this, as it feeds on floating food particles. In return, the sea anemone gains from clownfish activity; the sea anemone is vigorously defended by the inhabited clownfish, and also derives indirect/direct nutrients from its clownfish resident. The clownfish's swimming activity and excretions help circulate crucial marine nutrients to the anemone such as oxygen, ammonia, and phosphorous. Lastly, due to their bright colors, clownfish help attract larger fish to the anemone, which helps trigger the anemone to paralyze a potential food source.
Another amazing attribute that clownfish have involves their reproductive system. According to this additional article, clownfish are protandrous, and have the ability to change sex based on social factors. Essentially clownfish are hermaphrodites and are all born males. However based on colony social factors, a male will not change sex when attaining a certain size, but rather change after female disappearance. Essentially, when a female dies, the next in age, the dominant male, has the ability to change reproductive strategies of that found in female clown fish. Commonly referred to as "sequential hermaphroditism", this sex change is based off social factors within the colony, which is very unique to this specific taxa.
Who knew Marlin and Nemo were such incredible marine organisms? I think that species like these would be an absolute thrill to study. It would be very interesting to see the underlying molecular pathways involved in such advanced reproductive processes. Because clownfish have reached evolutionary extremes with both sex determination and symbiosis, it would be highly interesting to research their evolution, to see what kinds of enviromental pressures selected for these specific types of interactions and reproductive strategies.
-Elise Babula (1).
I wasn't aware that clownfish have the ability to switch sex based on social factors in their colony. You mentioned that all clownfish are born male and that a male can change sex due to the disappearance of a female. What determines which fish initially becomes the mother? Is there a specific type of mating strategy within this species?
ReplyDeletePosted by "Lauren Shone"
Clownfish have a strict dominance hierarchy within their colony. Only two anemone fish, a male and a female, will mate and reproduce. Usually the most dominant within the colony is the mother fish, followed by a dominant male. The other fish within the system are non-reproductive. If the mother fish dies however, the second largest male within the colony will convert to a female due to social pressures and absence of a "queen".
Delete-Elise Babula (1).
I did not know that anemones and clownfish shared a mutualism relationship! i wonder how the process of adapting to the poison of the anemone worked. In a video that i watched, it seems like they adapt their body to the levels and components of the mucus of the anemone. i will attach the link here, it gave a great summary about their relationship. https://www.youtube.com/watch?v=P-5ezc-2uD4
ReplyDeletePosted by "Pamela Jimenez"
I found this article to be very interesting, I was not aware that Clownfish and Anemone had a mutualistic relationship. It is interesting that the Clownfish swimming through the anemone helps to circulate nutrients to the anemone through the ocean water. I also did not realize that the Anemone was useful to the Clownfish other than for protection, but it does make sense that organisms paralyzed by the Anemone can provide as a food source to the Clownfish. The sex change information is also very interesting. Is there a specific order to which the males will change sex in, like some sort of hierarchy?
ReplyDeletePosted by "John Mariano"
Yes, there is a strict hierarchy within the colony. A typical anemone fish group consists of 3-6 individual; one individual consists of the female, and the others are males. The hierarchy is based on body size and aggressiveness. If the dominant female dies, the next largest fish within the group will change its gender and take its place.
Delete-Elise Babula (1).
Now why wouldn't they just tell you these things in Finding Nemo? All of this information on clown fish is very interesting. I feel like I've only ever seen the typical orange and white clown fish my whole life. Where do they hide all these other color clown fish? I think this fish has evolved very uniquely, bring able to have such a dependent symbiotic relationship and be able to change sexes in the absence of a mate is extremely beneficial to survival.
ReplyDeletePosted by "Joshua Gach"