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Sculptors of the Sea

From crop circles to fairy rings, we have always been fascinated by geometric patterns in nature and often attribute them to the supernatural. Just imagine the bewilderment of divers when they first discovered complex, ringed patterns on the seabed. There was a definite order to the ridges adorning the concentric circles, as if an architect directly realized a blueprint made with painstaking precision onto the transient sands. Soon, it was discovered that this was not the work of the paranormal, but rather the Torquigener albomaculosus, or white-spotted pufferfish. Over seven to nine days, this pufferfish will first create orientation markers with indents in the sand before using them to dig channels in a circular, coordinated fashion. Finally, the pufferfish will maintain the sculpture and decorate it with shells or corals.3 Like many grandiose displays in nature, this is a part of a mating ritual. While these sculptures are certainly aesthetically fascinating and demonstrate an unflinching dedication, female pufferfish also choose these rings because they serve an evolutionary purpose. The perfect coordination with which the peaks and valleys are created causes water to always flow from one side of the ring to the other, continuously supplying fresh water to the center – where eggs will be laid.2 Furthermore, the ridges direct water to flow in a circular motion, alleviating the shear stress on the eggs.

Even after understanding the hydrology of these nests or the mechanisms behind how they are made, this behavior remains a mystery. The Grass puffer seeks shelter instead to protect their eggs from currents, and male Porcupine puffers relentlessly chase and bite females to mate. As we zoom out of these underwater sculptures, fantastic architects with unique visions waiting to be studied are everywhere in nature. Emilio’s ground frogs have burrows that amplify acoustic signals by acting as a resonating chamber.5 Dramatic bowerbirds build elaborate stages for themselves to perform on in the hopes of attracting a potential mate.1 The sheer diversity of environmental communication present in the animal kingdom can make their mechanisms seem almost incomprehensible. However, it is imperative to understand these unique architectural communication methods not only because they are fascinating, but because the development of these behaviors holds rich information about the evolutionary history of these organisms.

The concept of an “extended phenotype” captures how genetics can influence not only an organism’s physical appearance, but also its behaviors and environmental interactions (Lauder, 2021). On the other hand, “niche construction” describes animal behaviors involving the active modification of their own niches according to a shifting landscape. his theory proposes that animals exert a certain degree of influence over their evolution with their architecture. Though these fields of emerging research appear to be conflicting in what they propose as the main evolutionary driving force for construction behaviors, they are complementary in demonstrating just how important the environment is in contributing to organism survival. For example, ants of the species Formica podzolica have been shown to change their nest-building and communication behaviors based on local temperature, meaning a global rise could significantly alter population distribution or community health.6 With how pufferfish nest architecture is dependent on currents, the warming of the ocean could significantly impact the health of this species. 

While we appreciate the artistry of these animals, we should also strive to learn about the incredible reasons behind how and why they build. Only then will we be able to understand the way our actions affect the Earth’s fellow residents, bridging the seemingly insurmountable language barrier between us.

References

  1. Donaghey, R. H., Belder, D. J., Baylis, T., & Gould, S. (2019). Nest, egg, incubation behaviour and parental care in the Huon Bowerbird “Amblyornis germana.” Australian Field Ornithology, 36, 18–23. https://doi/10.3316/informit.423644939343022
  2. Kawase, H., Kitajima, Y., & Iwai, D. (2022). 3D model of the geometric nest structure, The “mystery circle,” constructed by Pufferfish. Scientific Data, 9(1). https://doi.org/10.1038/s41597-022-01466-4 
  3. Kawase, H., Okata, Y., & Ito, K. (2013). Role of huge geometric circular structures in the reproduction of a marine pufferfish. Scientific Reports, 3(1). https://doi.org/10.1038/srep02106 
  4. Laidre, M. E. (2021). Animal architecture. Current Biology, 31(22). https://doi.org/10.1016/j.cub.2021.09.082 
  5. Muñoz, M. I., & Penna, M. (2016). Extended amplification of acoustic signals by Amphibian Burrows. Journal of Comparative Physiology A, 202(7), 473–487. https://doi.org/10.1007/s00359-016-1093-0 
  6. Sankovitz, M., & Purcell, J. (2021). Ant nest architecture is shaped by local adaptation and plastic response to temperature. Scientific reports, 11(1), 23053. https://doi.org/10.1038/s41598-021-02491-w
  7. Shameem, A. J., Valyrakis, M., & Zare-Behtash, H. (2021). A fluid dynamics approach for assessing the intelligent geomorphic design of the Japanese pufferfish nest. Geosciences, 11(1), 22. https://doi.org/10.3390/geosciences11010022