of Dytiscus sharpi

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When I heard the name of this Sharp Gengoroumodoki ( It was called so, formally in Japan ) for the first time, I considered that what a long and meaningful name they have. You already know what Gengorou means( If not so, please check the page of Cybister japonicus ), right? I didn't know that Sharp is person's name at that time. And Modoki means like [imitate]. They are sharp? Imitator? How now? So I just imagined that Sharp Gengorumodoki was awesome. They are the legitimate water beetle which looks very graceful as compared with Cybister japonicus. They feel noble. There are a reversed triangle mark on their foreheads. They are only a few and we worry.

Female sometimes has groove in the dorsae( Male has none ). It was unknown for what purpose is the groove.

This is male of Dytiscus sharpi. Outer temperature is 5 degrees. If you regard them to be cold ,poor and make them pass comfortably indoors, they will hardly lay eggs at the next breeding season. Since big species like them has a life for many years, they are utilizing change of the four seasons for breeding well. I am impressed that their breeding conditions are severe especially.

Male's forelegs like suckers are pasted up on Female's prothorax or around the head when Dytiscoidea mates usually. But D. sharpi is pasted up on Female's sides of prothorax with the suckers and catches surely around the insides by the claws. And the Male also has a suckers on mid-legs elaborately. These things may make the mating succeed mentioned above. The long legs has been used indeed effectively.

They has another group which is called validus ( Kogenmo in Japan ) in regional difference. It can be considered that subspecies relations. From a standpoint of environmental protection, we should not carelessly breed both together.

This is a 1st instar larva of Dytiscus sharpi. Their breeding season is early early spring. Larvae vigorously grow up in cold water.

Left is the 1st instar larva which feeds Asellus hilgendorfii. Right is the one which feeds tadpoles of japanese brown frog.

They are 3rd instars larvae. They does not has teeth of a saw at Clypeus like a genus Cybister has. But both fangs look very sharp. Cute but also terrible.

This is 3rd instar larva.

Dytiscus sharpi in summer hybernation. One August in my breeding tank.