It's been ages since I've been active here, college really took over my life. No complaints though, it was a great experience. Anyway, I figured I'd give you guys a long-overdue update. I recently got a male and female pair of yellow calvus, and it seems they've formed a bond. They're still pretty young, with the male only slightly larger than the female - about 1/8" difference, and both are around 2.5". They've claimed a spot in the back left corner of my tank, where they're guarding a rock. My guess is they might use it for breeding, which would be a first for me since calvus are typically shell dwellers and breeders.
Female keeping watch for intruders.
The pair's taken a liking to the rock in the back left corner of my tank, with the male identifiable by his bolder coloration and larger head proportions.