Hitchiker mantis

[Finland]

I received some great live rock from Tampa Bay Saltwater and was fortunate(IMO) to receive a 3 1/2 inch mantis as a hitchhiker. He was relocated to his own 40b. He has been in there for a couple months and yesterday he molted. Talk about a drastic color change!. He was a very dark brown w/ a dark emerald green underside. Now, after the molt, he is a solid green and much brighter in color. Is this normal? I am assuming he is a wennare(sp), since he came from the gulf. Any special care suggestions? Does the tank need sand for it to be healthy? Currently it has live rock and pea sized rubble. no sand. He spends the majority of the time inside a large piece of live rock. I have been feeding him frozen krill, whelks(I have a ton of hitcher whelks with the live rock), an occasional gorilla crab, and frozen shrimp. He seems nice and healthy, except for yesterday when he molted. He just laid there on his side w/ an occasional wiggle, but today is foraging around. I don't have a skimmer on the tank, but do weekly water changes with water from my 280 display. Should I get a skimmer on this tank? Currently, I have some lps corals and zoas in the tank that are thriving so I know the water quality is ok. Also, how big do wennare mantis get and how long do they live? Thanks for any info.

[nmotz]

Color changes are normal after a molt for Wenneraes. They are pretty easy to take care of and like to dwell in the rock itself. They don't need sand but they do occasionally like to hunt for snails in the substrate. You feed him a good, diverse diet so that's not a problem. You don't need a skimmer for a Wennerae tank. Your mantis is probably full grown at 3 1/2 inches and they can live as long as 5-10 years in some cases. Hard to tell how long yours will live since he was already full grown when you got him.