Halarachnidae, Oudemans, 1906

Vanstreels, Ralph Eric Thijl, Palma, Ricardo L. & Mironov, Sergey V., 2020, Arthropod parasites of Antarctic and Subantarctic birds and pinnipeds: A review of host-parasite associations, International Journal for Parasitology: Parasites and Wildlife 12, pp. 275-290 : 282-283

3.5. Parasitic mites ( Halarachnidae , Rhinonyssidae and Laelapidae )

Parasitic mites comprise nasal mites ( Halarachnidae and Rhinonyssidae ), which are found in the respiratory tract, and nest-associated haematophagous mites ( Laelapidae ). The complete life cycle of nasal mites develops within their hosts, relying on direct transmission via oral route (during chick feeding or courtship) or indirectly across water, perches, or other contaminated surfaces ( Bell, 1996). Five species of nasal mites have been recorded from Antarctic birds and mammals ( Table 2): two species in two genera of the Halarachnidae and three species in two genera of the Rhinonyssidae .

Halarachnidae comprises mites living in the respiratory tract of mammals, with Halarachne spp. infesting true seals ( Phocidae ) and sea otters ( Enhydra lutris ) ( Domrow, 1962; Furman and Dailey, 1980) and Orthohalarachne spp. infesting fur seals and sea lions ( Otariidae ) and walruses ( Odobenidae ) ( Popp, 1961). Halarachne miroungae (Ferris, 1925) has been recorded infesting southern elephant seals ( Mirounga leonina ) in the Antarctic region ( Domrow, 1962; Wilson, 1967, 1970b), and specimens of an undetermined species of Halarachne have also been recovered from the Weddell seal ( Leptonychotes weddellii ) ( Newell, 1947). Considering the difficulty in studying other species of true seals that breed sparsely on pack ice around Antarctica, it seems plausible that H. miroungae (or other yet undescribed Halarachne spp. ) might parasitize other hosts in the Antarctic region. Although Orthohalarachne spp. have not been recorded in the Antarctic region yet, Orthohalarachne diminuata (Doetschmann, 1944) was reported from Subantarctic fur seals ( Arctocephalus tropicalis ) in South Africa and at Gough and Amsterdam Islands ( Bester, 1989), and would therefore be likely to occur in breeding sites of Subantarctic fur seals within the Antarctic region (i.e. Prince Edward and Crozet Islands), perhaps with opportunities of transmission to Antarctic fur seals ( Arctocephalus gazella ).

Rhinonyssidae comprises mites living in the respiratory tract of birds. It is unclear whether Rhinonyssus schelli (Fain and Hyland, 1963) – which was recorded in Adelie penguins ( Pygoscelis adeliae ) and gentoo penguins ( Pygoscelis papua ) in the Antarctic region ( Wilson, 1967, 1970b) – should be reclassified as a subspecies of Rhinonyssus sphenisci Fain and Mortelmans, 1959 , which infests other penguin species in South America and Africa ( Vanstreels et al., 2019). On the other hand, species of Larinyssus are parasites of Charadriiformes , with Larinyssus orbicularis Strandtmann, 1948 infesting a number of gull ( Larus spp. ) and tern species ( Sterna spp. , Thalasseus spp. ) ( Strandtmann, 1948; Mitchell, 1961). Larinyssus orbicularis has not yet been recorded in the Antarctic region, but it is known to infest kelp gulls in South Africa and South America (Zumpt and Till, 1955; González-Acuña et al., 2011). Considering that rhinonyssid mites can go unnoticed for decades even when they are abundant in extensively studied hosts ( González-Acuña et al., 2011; Dimov, 2013; Vanstreels et al., 2019), it seems probable that the occurrence of these parasites has been underestimated in the Antarctic region.

Laelapidae comprises both free-living and parasitic mites, with the haematophagous mites of the genus Androlaelaps frequently found on mammals, especially rodents, but some species are also known to parasitize birds ( Strandtmann, 1949). These parasites are predominantly nest-bound, feeding on their seabird hosts during incubation and chick-rearing. Androlaelaps pachyptilae (Zumpt and Till, 1956) has been recorded on a variety of Antarctic procellariform birds, and within the Antarctic region it was recorded in the nest of Antarctic prions ( Pachyptila desolata ) at Heard Island (Zumpt and Till, 1956). Additionally, Androlaelaps farenholzi Berlese, 1911 was also recorded in the nest of fairy prions ( Pachyptila turtur ) in Australia ( Domrow, 1977). Because most studies of parasites from seabirds at Subantarctic islands have focused on collecting parasites from the hosts, rather than their nests, it seems probable that nest-associated haematophagous mites might be more widely distributed than currently known.