For the first time since I've had Boris (11 months), I witnessed Boris disengage his dactyl out from his arm for a cleaning. I have known they had the capability because I recovered an entire raptorial appendage during one of his first molts and disected it to see all the intricacies. When disengaged the "club" turns into a very sharp and barbed spear like that of a P. ciliata or other spearer, its not as fully developed for spearing and retracting fish..BUT, I think it gives him the capability of attacking and "opening" both hard crustacean flesh (club) and soft fish flesh (spear), probably something that has helped diversify and adapt to changes in their environment... I am sure Dr Roy has examined the possibilities...
(When i first got Boris, I fed him a goldfish, however he wouldn't bash it, and at first I was a little disappointed. Instead he would grab the fish by the tail and HOLD him under himself in his burrow for at least 20-25 minutes... somehow he was able to kill them this way or at least subdue them enough to stop any struggle, ANYWAYS, I swear that i saw him disengage something (I am assuming his dactyl) and use this "blade" to cut the underside of the fish from anus to gill. He shucked out the surgically eaten carcass of the fish leaving only the head, backbone and tail... I was impressed to say the least....
