the Editor says: Cephalopods are actually the creatures we commonly know as cuttlefish, bigfin reef squid, octopus, and their kin. You'll frequently spot them on dives, and they're equally familiar at the fish market and on the dinner table. Scientific research on cephalopods in Taiwan is still quite rare, yet Taiwan — situated along the Pacific island chain — has already documented 102 identified cephalopod species. This time, we'll first pull back the veil on these mysterious creatures through a documentary on a mother octopus filmed by Hung Yu-ting, then pair it with the book Illustrated Handbook of Cephalopods Found in Taiwan (Hardcover) to deepen our understanding of cephalopods!
Taiwan sits along the western chain of Pacific islands. Its western coast — aside from the Penghu Channel, which reaches depths of 200 m — is mostly shallower than 100 m, while the eastern coast plunges to 1,000 m just 5 km offshore. This dramatic variation in topography nurtures a remarkable diversity of species. As introduced in the Illustrated Handbook of Cephalopods Found in Taiwan (Hardcover), coverage is currently limited to species commonly seen at fish markets or those that are relatively easy to distinguish. As research progresses, we can expect even more cephalopod species to be identified in the future.
What Are Cephalopods?
There are over 800 species of cephalopods worldwide. They are ancient creatures that have inhabited the Earth since the Cambrian period. Their scientific name, Cephalopoda, derives from Greek roots meaning "head-footed animal," which tells us that their distinctive body plan has captivated human curiosity since time immemorial. They are found across every ocean on the planet — from polar to tropical waters, and from the surface all the way down to lightless depths of several thousand metres. Their rapid growth rate has made them a staple seafood protein across Asia, and they represent an important fishery resource.
Through millions of years of evolution, cephalopods abandoned their hard, cumbersome shells in favour of low-drag, streamlined bodies. By adopting jet propulsion as their primary mode of locomotion, they became the fastest-moving invertebrates in the ocean. Coupled with sharp eyesight and powerful arms, cephalopods have evolved into remarkably efficient underwater predators.
The Superpowers of Cephalopods
The hunting strategies of squid and octopus differ considerably. Cuttlefish and squid rely on their vision to locate prey, then shoot out a pair of long tentacles the moment a target enters striking range. Octopuses, on the other hand, supplement their vision with the suckers on their arms: as they crawl across the seafloor, they probe rocky crevices and reef shelves to detect prey hiding within, before snatching it in a single decisive move.
Cephalopods are not only formidable predators — they also possess extraordinary defence skills. These include rapid escape by jet propulsion, disorienting predators with ink clouds, and their truly remarkable ability to rapidly change body patterns. Beyond matching the colours of their surroundings through camouflage, they can even raise bumpy textured papillae across their skin and wave their arms in a convincing impression of swaying seagrass. Some octopuses can also secrete chemical toxins from their salivary glands — the blue-ringed octopus being the most well-known example, using vivid warning coloration and venom to signal that it is not to be trifled with. It's no wonder, with all these advantages, that cephalopods reign supreme in their aquatic domain!
The Illustrated Handbook of Cephalopods Found in Taiwan (Hardcover) not only covers cephalopod ecology and classification in detail, but also vividly describes their unique courtship rituals. For example, the spectacular body-pattern displays of the pharaoh cuttlefish (Sepia pharaonis) during mating can be observed every May at Ch潮境 (Chaojing), Keelung (the video below was filmed by Kyotaro at Chaojing Park, Keelung). The book also uses photographs to illustrate the differences between the eggs of octopuses, cuttlefish, and squid — making it an invaluable reference for anyone who wants to truly understand the full life cycle of cephalopods.
Most cephalopods live for only about a year. They grow quickly, but males die shortly after mating, and females follow suit after laying their eggs. You can watch the remarkable documentary below, filmed by Hung Yu-ting over the course of many dives in 2018, capturing a mother octopus in the act of spawning.
Based on the field guide, the octopus filmed by Hung Yu-ting appears to be Octopus sinensis d'Orbigny, 1841 — known in Chinese as the "Chinese octopus" and commonly referred to simply as octopus. Its mantle length can reach 250 mm and it can weigh over 2.5 kg. A benthic coastal species, it is a common sight at fish markets and holds significant commercial fishery value. It is widely distributed in waters along both the east and west coasts of Taiwan.
Like other cephalopods, octopuses have evolved complex brain regions that integrate sensory and motor systems. Some studies even suggest that cephalopods possess genuine learning ability and memory — for instance, an octopus can figure out how to retrieve food from a jar through repeated trial and error, and can also learn new techniques through observation.
Although this Illustrated Handbook of Cephalopods Found in Taiwan (Hardcover) is priced on the higher end, we're confident that anyone who reads it carefully will come away able to confidently distinguish between bigfin reef squid, cuttlefish, common cuttlefish, squid, loliginid squid, and octopus — whether at the fish market or underwater!
(The content in this article is excerpted from Illustrated Handbook of Cephalopods Found in Taiwan (Hardcover), published by the National Museum of Natural Science, and reprinted with permission by BlueTrend. Videos reprinted with permission from Hung Yu-ting and Kyotaro.)
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