Designing Nemo

by Harry F. Sanders, III on April 30, 2019

Most people think of clownfish as just one species, but there are actually 28 named species, mostly from genus Amphiprion with one from the closely related genus Premnas. Some of these species are likely either misclassified hybrids or hybrid species.1 And not all clownfish species are orange and white, like they are in the movies. They come in multiple shades of orange, red, pink, and even black, usually complete with at least one white stripe, though at least one species either completely or nearly lacks a stripe.

The defining characteristic of the clownfish is the ability to safely nestle into the tentacles of the anemone.

The defining characteristic of the clownfish is the ability to safely nestle into the tentacles of the anemone. Anemones are equipped with stinging structures called nematocysts. Anemones use these nematocysts to capture prey. It has been postulated that anemones use both mechanoreceptors and chemoreceptors2 to capture prey and that they are capable of deciding when to fire the nematocysts, based on feedback from the chemoreceptors.3 Yet clownfish are not stung, despite freely swimming in and out of the deadly tentacles. Numerous reasons have been proposed for this immunity. One author speculated that the immunity was acquired based on a period of acclimation to the anemones sting.4 This does not seem likely, given the potency of the sting. In a thorough study, another author proposed that the thickness of the mucus on the surface of the clownfish’s body was responsible for its protection, though the author did point to some cases of acclimatization.5

The mucus hypothesis seems to have been at least partially confirmed by an experiment which used a lotion containing chemicals found in clownfish mucus on swimmers and monitored their frequency of jellyfish stings. The chemical mixture was found to reduce jellyfish stings by 82%.6 Since jellyfish and anemones both sting using nematocysts of similar structure, this success seems to point to clownfish mucus as the mechanism of its protection. However, as one expert on clownfish pointed out, it is possible that acclimatization and mucus coating might be co-equal explanations depending on the species of anemones and clownfish involved and that more research is needed.7

More recently, a research journal from Asia postulated that the anemones fire their nematocysts based on the detection of a particular chemical. This chemical, N-acetylneuraminic Acid (Neu5Ac), is common in the mucus of most reef fish, but exists in only tiny amounts in one studied species of clownfish. The researchers proposed that since the clownfish lack this chemical, they are, in a sense, chemically invisible to the anemone’s nematocysts.8 This would go some distance toward confirming the aforementioned mucus hypothesis.

Clowning Around

Clownfish live in small groups with one adult male and female, along with several juveniles. They are matriarchal, with the head female being the largest member of the group.9 Juveniles begin their life as males. If the female dies, the male will undergo a change in sex to become female, while the largest juvenile matures to an adult male in order to reproduce.10 These juveniles, at least most of the time, are not merely children of the mature pair; instead, they are often unrelated.11 This helps maintain the genetic diversity of the species and reduces inbreeding.

Clownfish do not have the ability to hunt down a mate amid the mass diversity of the reef. They are not great swimmers, and leaving the protection of the anemone for too long would result in them being a colorful snack for a larger reef predator. Thus, if it were not for the ability of the fish to change gender when a mate dies, it would be very hard for the survivor to find a new mate. This would have quickly led to the extinction of the clownfish species. Both male and female reproductive organs exist in all clownfish at all times, whether they are functioning as male or female. However, the organ that is not in use is very reduced in size and is non-functional.12 It appears the changes in gender are controlled by hormones, particularly estrogen in the development of the female.13 This change occurs generally within two weeks of the loss or removal of the female.14

Clownfish lay eggs, generally right at the base of their anemone host. Adult pairs lay several hundred eggs in a clutch, though the exact size varies wildly.15 The eggs have special adhesive fibers that keep them from simply floating away.16 Generally, the clownfish spawn in time with sequences of the moon, anywhere from one to three times a month depending on food availability.17 The adults fan the eggs continually during the incubation period, either to aerate them or to keep them clean of debris.

When the clownfish larva hatch, they are only a few millimeters in length. They do not stay near their parents’ nest, instead taking to the open ocean as plankton. After maturing in the current and devouring other small plankton, the larva that survive their multitude of predators will reach the juvenile stage and begin to search for a host anemone. Because the larva cannot swim against the current, they can be dispersed long distances, with the longest known being around 400km.18

A Din in the Den

While most people do not think of fish as being vocal, clownfish are very vocal. They communicate regularly, producing sounds that vary from an aggressive, threatening noise to a more gentle clicking sound.19 They produce these sounds by rapidly bringing their teeth together, using a special sonic ligament attached to the lower jaw.20

The specialized lifestyle and reproductive cycle of the clownfish point strongly to a well-thought-out design.

The specialized lifestyle and reproductive cycle of the clownfish point strongly to a well-thought-out design. Getting a clownfish with its specialized lifestyle requires numerous specialized adaptations. They need to develop the mucus coat in particular, as well as their ability to make sounds. To breed, clownfish need to lay adhesive eggs. If the eggs were free-floating as some other fish eggs are, they would likely suffocate. Evolution has no explanation for the origin of these features.

This lack of evidence is borne out by the failure to explain clownfish evolution. One recent study attempted to extrapolate from clownfish speciation a macroevolutionary process but did not postulate an ancestor.21 Neither did a slightly earlier article which looked at the mitochondrial DNA of 23 clownfish species. While it described the possible lifestyle and body plan of the posited ancestor, it did not name the ancestor or cite any evidence to back up the proposed lifestyle. The article determined that these species were all descended from a single common ancestor.22 That conclusion is likely correct, but the ancestor was a clownfish. So to paraphrase, clownfish give birth to clownfish.

Despite the popularity of clownfish and many studies on them,23 evolutionists have made no attempt to explain how clownfish evolved, nor have they attempted to explain the origin of their symbiosis with the anemone. This should cause questioning of the evolutionary paradigm. If their dogma does not explain the origin of clownfish-anemone mutualism, which as yet it has not even attempted, then the evolutionary paradigm is really not intact.

Not So Salty

Rather than attempting to view these beautiful creatures through the evolutionary paradigm, it makes much more sense to view clownfish in light of the creation account described in the book of Genesis.

Interestingly some studies have been done with clownfish which provide at least tangential evidence to support a biblical flood model. During the flood, salt and freshwater would have mixed, at least in part, reducing the salinity of seawater. Since many saltwater creatures need at least some salt in the water to live, and many freshwater species have the opposite problem, many evolutionists attempt to use this fact to disprove the biblical account of a global flood. Clownfish provide a strong counterpoint to this claim. The current salinity of the ocean is around 34–36 parts per thousand. Yet a recent study pointed out that one species of clownfish larva can survive, unstressed, in water with salinity as low as six parts per thousand, much lower than the current ocean salinity.24 Given that salinity levels have been increasing since the flood, it appears clownfish would have had no difficulty surviving the Flood.

Clownfish are popular fish and rightly so. Their mutualism with the anemone strongly points towards a designer. Their ability to survive in low salinity also provides evidence that supports the biblical account of the flood. Rather than attempting to view these beautiful creatures through the evolutionary paradigm, it makes much more sense to view clownfish in light of the creation account described in the book of Genesis.


  1. Jeff Ollerton et al., “Finding NEMO: Nestedness Engendered by Mutualistic Organization in Anemonefish and Their Hosts” Proceedings of the Royal Society B 274, no. 1609 (2007): 591–598, doi:10.1098/rspb.2006.3758.
  2. Chemoreceptors are special nervous tissues that respond to chemicals outside the body of the organism, while mechanoreceptors are also nervous tissue, but respond to touch instead.
  3. Glen M. Watson and David A. Hessinger, “Cnidocyte Mechanoreceptors Are Tuned to the Movements of Swimming Prey by Chemoreceptors,” Science 243 (1989): 1589–1591 doi:10.1126/science.2564698.
  4. Richard N. Mariscal, “An Experimental Analysis of the Protection of Amphiprion xanthurus Cuvier & Valenciennes and Some Other Anemone Fishes from Sea Anemones,” Journal of Experimental Marine Biology and Ecology 4, no. 2 (1970): 134–149, doi:10.1016/0022-0981(70)90020-1.
  5. Roger Lubbock, “The Clownfish/Anemone Symbiosis: A Problem of Cellular Recognition,” Parasitology 82, no. 1 (1981): 159–173, doi:10.1017/S0031182000041962.
  6. David R. Boulware, “A Randomized, Controlled Field Trial for the Prevention of Jellyfish Stings with a Topical Sting Inhibitor,” Journal of Travel Medicine 13, no. 3 (2006): 166–171, doi:10.1111/j.1708-8305.2006.00036.x.
  7. Daphne G. Fautin, “The Anemonefish Symbiosis: What Is Known and What Is Not,” Symbiosis 10 (1991): 23–46,
  8. Najatual Suad Abdullah and Shahbudin Saad, “Rapid Detection of N-Acetylneuraminic Acid from False Clownfish Using HPLC-FLD for Symbiosis to Host Sea Anemone,” Asian Journal of Applied Sciences 3, no. 5 (2015): 858–864,
  9. Peter Buston, “Size and Growth Modification in Clownfish,” Nature 424 (2003): 145–146, doi:10.1038/424145a.
  10. K. Madhu and Rema Madhu, “Protandrous Hermaphroditism in the Clown Fish Amphiprion percula from Andaman and Nicobar Islands,” Indian Journal of Fishes 53, no. 4 (2006): 373–382,
  11. Peter M. Bunston et al., “Are Clownfish Groups Composed of Close Relatives? An Analysis of Microsatellite DNA Variation in Amphiprion percula,” Molecular Ecology 16, no. 17 (2007): 3671–3678, doi:10.1111/j.1365-294X.2007.03421.x.
  12. Margarida Casadevall et al., “Histology Study of the Sex-Change in the Skunk Clownfish Amphiprion akallopisos,” The Open Fish Science Journal 2 (2009): 55–58, doi:10.2174/1874401X00902010055.
  13. Laura Casas et al., “Sex- and Tissue-specific Expression of P450 Aromatase (cyp19a1a) in the Yellowtail Clownfish Amphiprion clarkia,” Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 155, no. 2 (2010): 237–244, doi:10.1016/j.cbpa.2009.11.004.
  14. Laura Casas et al., “Sex Change in Clownfish: Molecular Insights from Transcriptome Analysis,” Scientific Reports 6 (2016): doi:10.1038/srep35461.
  15. Peter M. Buston and Jane Elith, “Determinants of Reproductive Success in Dominant Pairs of Clownfish: A Boosted Regression Tree Analysis,” Journal of Animal Ecology 80 (2011): 528–538, doi:10.1111/j.1365-2656.2011.01803.x.
  16. T. T. Ajith Kumar et al., “Studies on Captive Breeding and Larval Rearing of Clown Fish Amphiprion sebae (Bleeker, 1853) Using Estuarine Water,” Indian Journal of Marine Sciences 39, no. 1 (2010): 114–119,
  17. J. R. Seymour et al., “Lunar Cycles of Reproduction in the Clown Anemonefish Amphiprion percula: Individual-level Strategies and Population-level Patterns,” Marine Ecology Progress Series 594 (2018): 193–201, doi:10.3354/meps12540.
  18. Stephen D. Simpson et al., “Long-Distance Dispersal via Ocean Currents Connects Omani Clownfish Populations Throughout Entire Species Range,” PLOS One 9, no. 9 (2014): doi:10.1371/journal.pone.0107610
  19. Orphal Colleye and Eric Parmentier, “Overview on the Diversity of Sounds Produced by Clownfishes (Pomacentridae): Importance of Acoustic Signals in Their Peculiar Way of Life,” PLOS One 7, no. 11 (2012), doi:10.1371/journal.pone.0049179.
  20. Eric Parmentier et al., “Sound Production in the Clownfish Amphiprion clarkia,” Science 316 (2007):
  21. Jonathan Rolland et al., “Clownfishes Evolution Below and Above the Species Level,” Proceedings of the Royal Society B 285, no. 1873 (2018): doi:10.1098/rspb.2017.1796.
  22. Simona Santini and Giovanni Polacco, “Finding Nemo: Molecular Phylogeny and Evolution of the Unusual Life Style of Anemonefish,” Gene 385 (2006): 19–27, doi:10.1016/j.gene.2006.03.028.
  23. Over 5,000 studies at least mention clownfish on Google Scholar. Accessed 03/20/2019.
  24. K. V. Dhaneesh et al., “Breeding, Embryonic Development and Salinity Tolerance of Skunk Clownfish Amphiprion akallopisos,” Journal of King Saud University-Science 24, no. 3 (2012): 201–209, doi:10.1016/j.jksus.2011.03.005.


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