Responses of Lumbricidae to Saline Inundation

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Abstract
A survey of the lumbricid populations of 2 localities in northwest England [UK] that had recently been inundated by the sea revealed a decline in density, biomass and species spectrum of Lumbricidae in proportion to the severity of inundation. Allolobophora spp. were dominant in all soils. Experimental flooding of soil with sea water demonstrated that Allolobophora spp. were not expelled as readily as Dendrobaena mammalis and Lumbricus spp. Of 6 spp. tested, all avoided 14.permill. salinity. Immersion in sea water of 29.permill. salinity was rapidly fatal to 8 spp. tested [A. caliginosa, Aporrectodea chlorotica, A. longa, A. rosea f. typica, Lumbricus rubellus, L. terrestris, L. castaneus and D. mammalis], A. longa and L. terrestria being most resistant; lumbricids expelled from soil by salt water would, therefore, rapidly perish. Lumbricid distributions in the field are consistent with D. mammalis and L. castaneus being rapidly killed by saline inundation while Allolobophora spp. are relatively resistant. Choice experiments and soil analyses suggested that conditions in the less inundated soils favored immigration of lumbricids. Since the viability of cocoons formed before flooding may have been unaffected by inundation, both immigration and breeding of survivors of inundation in situ will facilitate recovery of lumbricid populations. [Octolasion cyaneum was also discussed.].