Brian,
Guilty as charged of one of my own pet peeves - a failure to proof read a post.
Yes, Gonodactylus chiragra are tyically found in the mid to low intertidal living in cavities in shale, beach rock, bench , and rubble. They are rarely found in live coral. At Lizard Island where I do much of my work, the tidal extremes range from +.1 to +2.8 meters. We typically find adult G. chiragra in cavities from about .8 meters down to .1 m. I find most of them in cavities in the .3 - .6 m zone. They are typically most active on the incoming tides when the water around their cavity is only a few centimeters deep (predatory fish can't operate). This is when they make their foraging runs to collect snails and hermits that are returned to the cavity and broken during high tide. They are strictly diurnal and you never see them out from dusk to dawn..
The cavities typically have only one entrance which is perfectly round and just larger in diameter than the occupant. An 8 cm G. chiragra would have a fist-sized chamber with the entrance at the top so that when the tide is out, some water remains in the cavity. Obviously such cavities are rare and are nearly always occupied with competition for them intense.
Roy
