Limnohalacarus species

Bartsch, Ilse, 2018, Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology, Bonn zoological Bulletin 67 (2), pp. 79-99 : 84-85

Limnohalacarus species from the Afrotropical Region

The Limnohalacarus species recorded from the Afrotropical region are: L. africanus , L. cultellatus , L. fontinalis , L. major , L. marlieri , L. novus, and L. portmanni . Relying on often vague descriptions, the most specific mor- phological characters of the six African species are:

Limnohalacarus africanus . Characters (according to Walter 1935, Green 1984 and Bartsch 2013a): Length 330 µm, OC and gland pore-bearing sclerite separated, ventral plates separated, GA of female with 8–9 (up to 12 according to Green 1984) pairs of gac and three pairs of pgs, its genital sclerites with two pairs of sgs; L:W of female gnathosoma 1.6:1 ( Walter 1935: p. 74), but distinctly less in the deutonymph ( Walter 1935: fig. 4), none of setae on tibiae I bipectinate, pectines on claws I J-shaped and bearing numerous long tines. Distribution: Burkina Faso ( Upper Volta) (well at Banfora) ( Walter 1935), West Cameroon (Debundska Lake) ( Green et al. 1974), South Sudan (Lake No) ( Green 1984).

Limnohalacarus fontinalis . Characters (according to Walter & Bader 1952 and Bartsch 2013a): Length 310–370 µm, gland pore included in elongate OC; ventral plates fused, L:W of gnathosoma 1.1:1; tibiae I to IV with 8, 7, 7, 6 setae, respectively, claws I with numerous long tines. Distribution: Kenya ( Mombasa, from well with slightly saline water) ( Walter & Bader 1952), South Sudan (Lake No) ( Green 1984).

Limnohalacarus major . Characters (according to Ba- der 1968): Length 465 µm, distinctly larger than the other species (their length 224–370 µm), gland pore included in elongate OC; ventral plates fused, gnathosoma slen- der, its L: W 1.6:1. Distribution : DR Congo (Zaire) (Lake Tanganyika) ( Bader 1968) .

Limnohalacarus marlieri . Characters (according to Bader 1968 and André & N’Dri 2012): Length of female 305 µm, of male 350 µm. OC elongate, 1.4 times longer than wide. Length ratio PD:AD 3.4:1. Ventral plates fused. Female with eight pairs of gac posterior and posterolateral to GO. Number of gac along margins of area representing GA not known. Gnathosoma short, L: W 1.1 –1.2:1. Limnohalacarus marlieri is very similar to both L. fontinalis and L. portmanni , it is classified as a junior synonym and omitted in the following key. Distribution: DR Congo ( Zaire) (Lake Tanganyika) ( Bader 1968).

Limnohalacarus portmanni . Characters (according to Bader 1967 and Bartsch 2013a): Length of females 224–250 µm, of males 217–289 µm, gland pore included in elongate OC; length ratio PD:AD 3.1–3.3:1; ventral plates fused, L:W of gnathosoma 1.2:1. Female with up to seven pairs of gac and three pairs of pgs, each genital sclerite with (two to) four sgs. All claws with J-shaped arranged pectines. Distribution: DR Congo ( Zaire) (Lake Tanganyika, from shallow water sediment) ( Bader 1968).

Characters of Limnohalacarus cultullatus and L. novus are outlined above.