1Horseshoe crab Museum breeding


In rare species, also referred to as a living fossil、2Than billion years ago without changing the appearance inhabit。The Red Data Book of the Ministry of the Environment has been classified as endangered species Class I。

As appearance is said to be the origin of the name of the horseshoe crab、Perhaps it is easy to understand better that figure, such as crab, which was carrying a round helmet。Here Imari、Is called the Hachigame Imariwan of character "bee round you" that it imitates has also been popular。6You can see the spawning of horseshoe crabs in Imari Tatara coast sieved month to August。




Eggs of horseshoe crab is a milky white with a diameter of about 3 mm、200Will be lays in the sand at 300 eggs mass state -。The characteristics of the occurrence、It is that the four times of molting is performed in a state of embryo。Shows through the middle you will see in about 30 days。This is called the timing and pumpkin embryos。Soon、Slowly rotating back around in the egg membrane in a state in which the most able to form of larvae。It refers to this period as the rotation egg、after that、Breaking the egg membrane、50And a hatch in the day about。

Hatched larvae is、1Although it referred to as the age larvae、Also called trilobites type larvae from its resemblance to the trilobite。1Age larvae leaves pushes up the sand in the sea water at the time before and after the high tide of the spring tide of early October from late September in the physical condition 6mm、Riding the ebb tide to move to the tidal flats、This winter in tidal flats。

From the spring after wintering、We will continue to molting growth。Each time you molting、We will increase the number of the age of the larvae。First instar larvae will be the second-instar larvae and molt once。Molt、It has come out from the front of the front body part。After molting is、About 1.2 will be large enough to 1.3 times。The color of the larvae is as inconspicuous to predators in the protection colors similar to the tidal flats of mud。The first instar larvae of the full-length 6mm、Body length of 50 to molt many times until the adult 60cm、We did not know well what year take the、Examples of individuals molt 14 times from the egg by the long-term breeding after 11 years by researchers became female adult Ya、10Such as the example year or me 13 times molting individuals has become the male adult has been reported。Also、For subsequent life、Not yet known。


Horseshoe crab table Horseshoe crab back





Larvae hatched on the beach will grow in the tidal flats of the growth area riding the wave。It has a bait such as worms in the tidal flats。The Will to say that as the environment in which we also grew up larvae that easy hiding somehow the color of the tidal flats。It will be to 15-17 once adult molting。Without much action、Speakeasy we are staring down the tidal flats of mud。

Masu Yuki out to sea with a water depth from when adult。6Mon-August night of spring tide、It lays the eggs turn and become to the beach。Mud crab that live in this area (crab) also have similar spawning season is well、Ecology I think that is very similar to crab。

1Horseshoe crab growth 2Horseshoe crab mating 3Male model 4Female model