Happy Earth Day! How are you celebrating? I just finished up my yellowfin tuna painting for this post this morning and might go out for a short bike ride to enjoy the recent warm spring weather we're having!
Edit: this is an archive blog now, the blog has moved to livinseas
The tiny hummingbird bobtail squid (Euprymna berryi) is a particularly visually striking cephalopod due to its bright coloration and dark chromatophores. While often mistaken for cuttlefish, the notoriously adorable bobtail squid are classified within their own phylogenetic order and lack the distinctive cuttlebone characteristic to cuttlefish.
I painted this watercolor around a month and a half ago, inspired by a video where a cute little hummingbird bobtail squid was using its teeny tiny arms to shove comparatively large grains of sand over its body so it could bury itself.
Cephalopods are invertebrates, which means they lack a vertebral column. While other invertebrates, such as jellyfish, insects, and sponges, are not exactly known for their cerebral prowess, cephalopods are extremely intelligent and have a highly complex nervous system, well-developed senses, and large brains. This has given cephalopods special legal recognition as sentient beings.
It is difficult to study cephalopods in a laboratory setting due to behavioral complexities, difficulties obtaining multi-generational cultures, and frequent feeding requirements. As such, cephalopod research is limited. Euprymna berryi has shown promise as a laboratory model species, since its small size and behaviors suit these settings well. E. berryi will also breed in captivity, facilitating multi-generational studies.
One study (Putland et al., 2023) conducted on E. berryi has found that their behavior and physiology are significantly altered when exposed to vessel noise, even up to several hours following exposure. Anthropogenic influence is a significant threat to marine ecosystems globally, including human-caused sounds, which continue to grow louder and more widespread throughout our oceans. Through studies like these, we are better able to understand our impacts on the natural world and strengthen the scientific body of literature surrounding these issues. Strong, science-based evidence can then be used to shape legislation and management practices to protect our oceans. Even the tiniest squids can have a massive, positive impact! 🦑
Sources:
Jereb, P. and C.F.E. Roper (eds.) 2005 Cephalopods of the world. An Annotated and Illustrated catalogue of Cephalopod species known to date. Vol. 1. Chambered nautiluses and sepioids (Nautilidae, Sepiidae, Sepiolidae, Sepiadariidae, Idiosepiidae and Spirulidae). FAO Spec. Cat. Fish. Purp. 4(1):262p. Rome: FAO.
Jolly, J., Hasegawa, Y., Sugimoto, C., Zhang, L., Kawaura, R., Sanchez, G., ... & Rokhsar, D. (2022). Lifecycle, culture, and maintenance of the emerging cephalopod models Euprymna berryi and Euprymna morsei. Frontiers in Marine Science, 9, 1039775.
Gilmore, R., Crook, R., & Krans, J. L. (2016). Cephalopod camouflage: cells and organs of the skin. Nature Education, 9(2), 1.
Meyer, F. (2013). How Octopuses and Squids Change Color. Smithsonian National Museum of Natural History. https://ocean.si.edu/ocean-life/invertebrates/how-octopuses-and-squids-change-color.
Putland, R. L., Mooney, T. A., & Mensinger, A. F. (2023). Vessel sound causes hearing loss for hummingbird bobtail squid (Euprymna berryi). Frontiers in Marine Science, 10, 1151605.
Salvador, R. B., & Cunha, C. M. (2016). Squids, octopuses and lots of ink. Journal of Geek Studies, 3(1), 12-26.
Ukrow, J., Renard, M. D., Moghimi, M., & Laurent, G. (2025). CHROMAS: A Computational Pipeline to Track Chromatophores and Analyse their Dynamics. bioRxiv, 2025-03.
WoRMS Editorial Board (2025). World Register of Marine Species. Available from https://www.marinespecies.org at VLIZ. doi:10.14284/170
