Let's explore our amazing underwater life of Hong Kong!
Subvented by the Agriculture, Fisheries and Conservation Department. Any opinions, findings, conclusions or recommendations expressed in this material/ event do not necessarily reflect the views of the Government of the Hong Kong Special Administrative Region.

Cone snail
Does this snail look very colourful to you? Though it may look very attractive, it is indeed one of the most venomous snails and the last snail you may want to touch if you happen to see them on a beach or under the sea. They can stretch out their proboscis, tipped with a harpoon-like tooth at the end, to eject venom into their prey. The venom acts as neurotoxins, and is so strong that even human deaths have been attributed to them. So please make sure you will be aware of it when exploring the Hong Kong shoreline and sea!
𝘏𝘰𝘭𝘰𝘵𝘩𝘶𝘳𝘰𝘪𝘥𝘦𝘢 (𝘔𝘦𝘳𝘵𝘦𝘯𝘴𝘪𝘰𝘵𝘩𝘶𝘳𝘪𝘢) 𝘭𝘦𝘶𝘤𝘰𝘴𝘱𝘪𝘭𝘰𝘵𝘢
Although they may look ordinary to you, they are actually one of the most common sea cucumbers in Hong Kong! They also have a very important role under the sea - maintaining the balance of the nutrient cycle.
When threatened, this sea cucumber discharges a white and sticky substance out of their anus to snare their predators. This substance is known as Cuvierian tubules, which are their internal organs. When they are safe again, these tubules will be regenerated quickly. But one gentle reminder: the regeneration of the Cuvierian tubules is very energy-demanding, so please don’t ever try to trigger this defensive mechanism if you’ve got a chance to see them in the wild!


𝘋𝘪𝘢𝘥𝘦𝘮𝘢 𝘴𝘦𝘵𝘰𝘴𝘶𝘮
Long-spined sea urchin have sharp and slender spines, which vary in length. It is characterised by a distinct bright orange ring that looks like an eye! In fact, it is not an eye, but the excretory organ (anal cone) of the sea urchin.
Although their spines seem threatening, they indeed help to support marine biodiversity by providing a safe haven for small shrimps, crabs or fishes! Still, we'd better keep our hands off the sea urchin when we encounter them in the sea. Trust me, you don't wanna feel the pain!
𝘏𝘦𝘭𝘪𝘰𝘤𝘪𝘥𝘢𝘳𝘪𝘴 𝘤𝘳𝘢𝘴𝘴𝘪𝘴𝘱𝘪𝘯𝘢
What do you know about the short-spined sea urchin? The deep purple coloured urchin may not look very attractive, but you may have tasted it before you like sashimi! By the way, do you know which part of urchin are you actually eating? The bright yellow-orange edible part of sea urchin is their gonads!


𝘚𝘢𝘭𝘮𝘢𝘤𝘪𝘴 𝘴𝘱𝘩𝘢𝘦𝘳𝘰𝘪𝘥𝘦𝘴
Urchins are typically with a spiny and hard shell, and usually feed on algae. Different types of urchins may not only have distinctive colours, but the length, thickness and even distance between spines may vary too! This urchin featured in the graphic today, is special in a way that it loves to collect little things like stones, shells or algae pieces, to “decorate” itself.
𝘔𝘢𝘴𝘵𝘪𝘨𝘪𝘢𝘴 𝘱𝘢𝘱𝘶𝘢
Papuan jellyfish is one of the commonly found jellyfish species in Hong Kong. It is characterised by the pale yellow spots on their semi-transparent bell. Their body is usually observed to be greenish blue to olive green because of the zooxanthellae that live symbiotically within the jellyfish.
Warm reminder: As jellyfish may inject venom into your body when triggered by touch, let's remember to show your respect by not touching them no matter where you meet them!
