Report associated with sponges: This species (reported as Halacarus murrayi) was found among sponges and algae (Lohmann 1889). This species was also reported in empty Ostrea valves extensively pitted by sponge Cliona sp. from New Haven harbour, Long Island Sound, Eastern North America (Newell 1947).
Remarks: This was recorded on various substrata: sediments, algae, sponges, and bryozoans from Boreal North Atlantic, European and American shores (Newell 1947; Bartsch1998a; Chatterjee 2022). This species was also found amongst cuticular structures of spider crab Libinia emarginata (Arthropoda, Crustacea, Malacostraca, Decapoda) from Rhode Island, USA (Bartsch 1979 a; Chatterjee 2021a).