Meeting Abstract
Philomycus slugs and green salamanders, Aneides aeneus, are commonly found in the same rock crevices in sandstone rock cliffs. Previous studies suggested that any interactions of A. aeneus with slugs in crevices likely were not beneficial for either species. Also, the presence of slugs in A. aeneus breeding crevices may be harmful to the eggs. However, I have observed twelve instances in which A. aeneus (adults and young) were in direct contact with single Philomycus slugs in rock crevices with no apparent ill effects. This water-conserving posture may reduce the surface area exposed by the two animals such that water loss would be minimized and may allow survival over short dry periods until humidity or moisture levels increase. In some cases, additional water conserving measures were observed, including pressing of the tail against the side of the body and coiling it over the head. Both species have a moist integument and thus are readily subject to evaporative water loss. While opportunistic, this aggregative behavior by both species may be adaptive and beneficial. One possible negative effect was in the case of a large slug present in a small A. aeneus brooding crevice which may have prevented deposition of her eggs. The aggregative behavior observed here indicates that interspecific cooperation or mutualistic symbiosis with regard to water economy may be important for some individual slugs and salamanders.
