A watercolor painting done by LivInSeas featuring a hummingbird bobtail squid. The squids body is a faint, dusky purple color, and its covered with large patches of whitish or fluorescent blue/green color. The eyes are horizontal slit shapes. Five tentacles are visible, each having a line of fluorescence running down the center of each arm. The squid is covered in black spots across the entire body. The black spots are larger on the arms and lower body of the squid, and much smaller on the upper body.

Species Spotlight: Hummingbird Bobtail Squid

ByLivInSeas

The tiny hummingbird bobtail squid (Euprymna berryi) is a visually-striking cephalopod. It features a bright, fluorescent coloration and dark chromatophores. While often mistaken for cuttlefish, the notoriously adorable bobtail squid are classified within their own phylogenetic order. And, they lack the distinctive cuttlebone characteristic to cuttlefish.

My source of inspiration for this watercolor painting I created for my LivInSeas platforms came from a TikTok! In this video, 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.

A watercolor painting done by LivInSeas featuring a hummingbird bobtail squid. The squids body is a faint, dusky purple color, and its covered with large patches of whitish or fluorescent blue/green color. The eyes are horizontal slit shapes. Five tentacles are visible, each having a line of fluorescence running down the center of each arm. The squid is covered in black spots across the entire body. The black spots are larger on the arms and lower body of the squid, and much smaller on the upper body. Pin It

Water color painting of a Hummingbird Bobtail Squid (E. berryi) by me. ©LivInSeas, 2025

Cephalopods are invertebrates, which means they lack a vertebral column. Other invertebrates, such as jellyfish, insects, and sponges, are not exactly known for their cerebral prowess. However, 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.

Range & Habitat:

E. berryi is native to tropical waters in the central Indo-Pacific, ranging mainly from Indonesia to southern Japan and China.

It lives in coastal, benthic habitats and prefers fine and sandy sediments. During the day, the squid will bury themselves in the sand to avoid predators. They emerge at night to feed or mate with other hummingbird bobtail squid. 

E. berryi are found in shallow waters down to 107 meters (351 feet). 

A photograph of a hummingbird bobtail squid. The squid is mostly buried in the rocky sediment, with just its two eyes and two tentacles visible above the sediment. The eyes are a glittery pale green, with a slim horizontal pupil. The body visible around the eyes is covered in black spots, reflecting a fluorescent peacock green and blue in color. The arms look mostly translucent, but there are flashes of fluorescence running down them, dark blue closer to the body transitioning to light blue, then green, then yellow. Pin It

A hummingbird bobtail squid burying itself in the sand. Image sourced from Kwajalein Underwater, 2025. (Please check out the many other adorable photos of E. berryi on this site! So adorable.) 

Morphology:

Squid are measured by mantle length, which refers to their upper body cavity. The mantle houses the squid’s organs. Squids intake water into the mantle over their gills, then expel it through their siphon, which can be directed directionally.

Males of the species are smaller than females. The mantle length of males measures up to three centimeters (roughly 1.2 inches), while females mantle lengths can measure up to five centimeters (roughly two inches). 

An infographic of external anatomical features of a squid. Arrows point to different features. These include the fins (two symmetrical fins sit opposite of each other at the top of the body), the mantle (the main upper body cavity of the squid--pretty sure this is the part the calamari rings come from), the siphon (a tube protruding from the mantle), eye, arms (the eight shorter limbs), tentacles (the two longer limbs), and suckers at the end of the tentacles. Pin It

An annotated image depicting the external features of a squid, including the organ-housing mantle. Image sourced from Critter Squad Wildlife Defenders.

E. berryi have chromatophores, or neuromuscular organs located within the skin. They’re comprised of one pigment-containing cell surrounded by radial muscles which control expansion and contraction of the cell. Chromatophores help the squid disguise from being spotted by predators through camouflage and for communication with other hummingbird bobtail squids. The cells are controlled neurally and can be opened within milliseconds.

Vertebrate predators hunt by looking for visual edges or breaks in the background. Using chromatophores to match background textures allows cephalopods to blend in. This is referred to as crypsis.

Typically, chromatophore pigments are black, red, yellow, or brown. Additional colors can be obtained with reflective cells called iridophores.

Interestingly, cephalopods are believed to be colorblind.

Bobtail Squid as Model Species:

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.

Members of a bobtail squid subfamily Sepiolinae, including Euprymna berryi, are particularly suitable in laboratory settings. The squid are small and have limited nutritional requirements, which is ideal for an aquaria setting. They also have short lifespans and reproduce in captivity. This makes them well-suited for studies which span multiple generations of squid. Sepiolinae squid also do not have cannibalistic tendencies, which allows them to be housed together.

One study (Putland et al., 2013) 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, or disturbance caused by humans to the environment, is a significant threat to marine ecosystems globally. This includes human-created 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 the biggest impact!

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A infographic about the hummingbird bobtail squid, featuring an original watercolor painting. The squid is somewhat fluorescent in color, with splashes of green, blue, purple, and silver. it is covered in small, black dots. The text reads: "Original watercolor by LivInSeas. Hummingbird bobtail squid (Euprymna berryi). native to tropical waters in the central Indo-Pacific. lives in coastal, seafloor habitats. prefers fine, sandy sediments to bury itself within. found in shallow waters down to 107 meters. invertebrates lack a vertebral column. have chromatophores - neuromuscular organs in the skin that help the squid camouflage. crypsis: the ability to match background. important species in laboratory science. suit aquaria settings well. using E. berryi, researchers demonstrated vessel noise significantly alters organism behavior. Pin It

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