[On the biology and ecology of halacarus basteri basteri Johnson 1836]

Abstract

The carnivorous marine mite Halacarus basteri was reared on blotting paper in artificial sea water of different salinities. The mites find their food by aid of chemically working sense organs which are situated on the tarsi of the first pair of the legs and perhaps at the top of the pedipalpi. All stages of development straddle with their legs when in open water. Thus the legs become gliding filaments which reduce the sinking speed. Development from egg to the propagating mite takes one year. Sperm transmission is carried out indirectly by spermatophores (Fig. 2).In their normal range of life (salinity from 8 to 25‰) the mites behave poikilosmotic and hyperosmotic. Between 25 and 45‰ they show a hypertonic-hypotonic regulation (Fig. 3). In extreme salinities the mites swell or shrink; they recover in normal salinity (Fig. 4). The mites stand extremely low temperature without damage (Fig. 5).