Horseshoe crabs: Q&As

What do horseshoe crab eat?
Horseshoe crabs feed on mainly insect larvae, worm, mollusks and sometimes small fish and crabs.

How do I distinguish male and female horseshoe crab?
In general, female horseshoe crabs are larger in size than male horseshoe crabs. Also, the mature male horseshoe crab will develop a modified first pair of legs which is used for clasping onto the female when mating.

How many species of horseshoe crab can be found in Hong Kong?
Two. The Chinese horseshoe crab Tachypleus tridentatus (TT) and the mangrove horseshoe crabs Carcinoscorpius rotundicauda (CR).

Which seasons can we observe horseshoe crab in Hong Kong?
The active period of juvenile horseshoe crabs in intertidal zone in Hong Kong is from April to October.

What time of a day is easier to find horseshoe crab on the beach?
Horseshoe crabs emerge from the sediment at low tide to feed. You can check the Hong Kong Observatory for tidal information at different locations (

How can I find horseshoe crabs in the field?
Horseshoe crabs leave three parallel traces on the mudflat when they are crawling on it.