The second of the three Mexican redknee tarantulas (Brachypelma smithi) obtained in January, 2012 completed its fourth molt Tuesday night, October 16, 2012. (Update: The third sibling molted October 28, 2012).
Upon initial inspection the tarantula looked fine. A closer look revealed its third right leg to be significantly smaller and lacking in coloration. At first I thought the leg was still enclosed in the previous exoskeleton, though if that were the case, the leg should have appeared more heavily pigmented.
Examination of the the newly shed exoskeleton indicated the spider had seven legs prior to the molt. The smaller, less heavily pigmented leg had apparently developed (in its entirety!) pressed against the body over the eight weeks since the spider’s previous molt. Quite impressive!
Currently the leg has some movement capabilities, but does coordinate well or synchronize with the other legs.
It will be interesting to see the degree of coordination and pigmentation that develops over the next few weeks, as well as the structure of the leg and the development of coloration after the next molt.
Written Wednesday, October 17, 2012.