This is a nice Sukashi tsuba of the Owari school with a crab.
Sensei wrote a comment about crabs in reference to the martial arts in an earlier Daily Message on November 17, 2004.
There is another type of crab that comes onto the beach with the tide and quickly burrows into the sand. Japanese love to eat these crabs but they are hard to find in the sand and it is a lot of work to dig them up because they are very small and very quick. The way they catch them is to take a pencil and start poking the sand. The poking effect seems to resemble the effect of the tide rushing onto the beach so the crabs will poke their head up out of the sand so the water will carry them back into the sea. When the crabs pole their heads up, they are grabbed by the hungry fisherman.
Anyways, we can be caught very easily - when the opponent understands how we act.