taxonID	type	description	language	source
03F38B72FFC1FFD3F517F8F3FA4AA225.taxon	description	Short description (Fig. 1 A – E). Female: Length of idiosoma 255 – 290 µm [3]. OC and platelet with gland pore separated by striated integument (Fig. 1 A), OC about 1.1 times longer than wide. Corneae and spots with eye pigment lacking. AE, PE and GA separated by striated integument (Fig. 1 B). Pair of ds- 6 present on anal cone (obscured by genital sclerites). GP with four to five pairs of gac, three to four pairs of pgs, genital sclerites with two pairs of sgs. Gnathosoma 1.5 – 1.7 times longer than wide; pharyngeal plate distinctly removed from basal margin of gnathosoma. Both pairs of maxillary setae slender (Fig. 1 C). Legs shorter than idiosoma, length ratio leg I: idiosoma 0.7: 1. Length of telofemur I 1.8 times the height (Fig. 1 D). Basifemora I to IV with 4, 3, 2, 1 setae, tibiae I to IV with 7, 6, 7, 6 setae. Tibiae I and II each with one bipectinate seta, tibiae III with two bipectinate ventromedial setae, tibia IV with slender, smooth ventral setae. Claws on leg I slender, apically with few (8 – 10) minute tines (Fig. 1 E), basal lamellar process with four tines. Male: Not present. Juveniles: Length of deutonymph, protonymph and larva 240 µm [1], 200 µm [1] and 155 µm [1), respectively. Dorsal aspect similar to that of females. AE of larva with pair of epimeral pores. In nymphs GP and anal plate separated by striated integument, in larvae GP lacking.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC1FFD3F517F8F3FA4AA225.taxon	discussion	Remarks. Limnohalacarus cultellatus can be distinguished from the other African Limnohalacarus species by combination of: dorsal and ventral plates separated and pectines on claws I much more delicate than on claws II to IV. Notes on African Limnohalacarus species are given below.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC1FFD3F517F8F3FA4AA225.taxon	biology_ecology	Biology. At present there is no record of a male, neither from Africa nor from other parts of the world. One of the females included an ovoid excretory body, 125 µm long, 60 µm wide, the centre (10 µm in diameter) is dark, the margin hyaline and delicately stratified. One of the females held an egg, 50 µm long, 55 µm wide. Geographical distribution (Fig. 2) (cf. Bartsch 2011, 2013 a; Pepato & Dos Santos Costa 2015; Ojeda et al. 2016): Afrotropical Region. – Madagascar; Palaearctic Region. Europe: – Hungary; Oriental Region. – India (Andhra Pradesh); Nearctic Region. – United States (Georgia, Wisconsin?); Neotropical Region. – Brazil (Mato Grosso, Rio Grande do Sul) – Cayman Islands (Grand Cayman) – El Salvador – Mexico (Quintana Roo) – The Netherlands Antilles (Bonaire, Curaçao) – Venezuela (Margarita Island).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	materials_examined	Collecting data. Central Madagascar, Antananarivo, Anjazorobe, River Ranonisoanavola (larger stream E from main mountain chain), 1200 m asl, 13.2 ° C, 0.058 mS / cm, interstitial, 23 Jul. 2001 (MD 012). – South-eastern Madagascar, Fianarantsoa, Ionilahy, stream draining area Marosaro (S from River Ionilahy), 220 m, 21 ° C, 0.072 mS / cm, interstitial, 12 Aug. 2001 (MD 023). – South-eastern Madagascar, Fianarantsoa, Ionilahy, River Ionilahy, 200 m, 23 ° C, 0.059 (11. Aug.) – 0.088 (13. Aug.) mS / cm, interstitial, 11 / 13 Aug. 2001 (MD 026). – South-eastern Madagascar, Fianarantsoa, Ionilahy, small stream crossing the railroad east from village, 200 m, 19.9 ° C, 0.083 mS / cm, 15 Aug. 2001 (MD 027). – Southern Madagascar, Tulear, Tsimelahy, River Antarantsa, ca 1 km upstream from village, 300 m, 20.4 ° C, 0.171 mS / cm, interstitial, 04 Sep. 2001 (MD 058). – Central Madagascar, Antanarivo, Ankaratra, Reserve Manjakatompo, left affluent of River Mahiavona, EM Mantsina, 1750 m, 14.1 ° C, 0.003 mS / cm, interstitial, 08 Oct. 2001 (MD 107). – North-western Madagascar, Majunga, Adjamangirana, stream in dry forest, upstream, rice field area (road to the village of Tsaratanana), 220 m, 30.8 ° C, 0.008 mS / cm, interstitial, 19 Oct. 2001 (MD 115). – Northern Madagascar, Antsiranana, Antalaha, Marofinaritra, River Antsohibe, upstream confluence with River Ankavia (5 km NE Amparihimena), 70 m, 25.2 ° C, 0.008 mS / cm, riffle, 03 Nov. 2001 (MD 135). – Northern Madagascar, Antsiranana, Antalaha, Marofinaritra, River Andranomenaheli, upstream confluence with River Ankavia (right affluent below MD 135), 70 m, 22.3 ° C, 0.009 mS / cm, riffle, 04 Nov. 2001 (MD 136 a). – Northern Madagascar, Antsiranana, Maroambihy (Sambava), left affluent of River Lokoho upstream from the village, 90 m, 26.0 ° C, 0.010 mS / cm, interstitial, 12 Nov. 2001 (MD 149). – Northern Madagascar, Antsiranana, Joffreville (M. d’Ambre), River Antomboka, downstream large cascade, 850 m, 20 Nov. 2001 (MD 163). – Northern Madagascar, Antsiranana, Joffreville (Montagne d’Ambre), River Manques in Reserve Fontenay, 580 m, interstitial, 21 Nov. 2001 (MD 165).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	description	Short description (Fig. 3 A – G). Female: Length 206 – 289 µm [20]. OC including platelet with glp- 3 (Fig. 3 A), L: W of OC 1.4 – 1.6: 1. Length ratio of PD: AD 2.6 – 2.7: 1. Pair of ds- 2 absent. Ventral plates AE, PE and GP fused (Fig. 3 B). Area corresponding to GP with three pairs of pgs, five to six pairs of gac and on each genital sclerite two (three) sgs. Ovipositor short and narrow (LxW 74 x 10 µm), very faintly sclerotized, genital spines very delicate and short, 2 µm in length, and arising from minute papillae (Fig. 3 D). Anal slit less than 10 µm long and guarded by pair of short anal sclerites. Gnathosoma about 1.1 times longer than wide. Pair of mxs- 2 shorter but wider than mxs- 1 (Fig. 3 E). Legs shorter than idiosoma, length ratio leg I: idiosoma 0.7: 1. Length of telofemur I 2.1 – 2.3 times the height (Fig. 3 F). Tibiae I to IV with 8, 7, 7, 6 setae [14]. Ventromedial seta on tibia II and both ventromedial setae of tibia III bipectinate; setae on legs I and IV smooth. Claws I to IV with J-shaped arranged pectines (Fig. 3 G), extending from apical lateral flank and along medial flank to basis of claw. On claws II to IV basal tines partly fused to a lamellar process. Male: Not present. Juveniles: Length of deuto-, protonymphs and larvae 231 – 275 µm [13], 180 – 226 µm [7] and 142 – 170 [5] µm, respectively. In contrast to adults, OC and posterior gland-bearing platelet separated by transverse striae. Ventral plates AE, PE and GP of nymphs separated from each other by striated integument, in larvae GP absent and AE with pair of epimeral pores.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	biology_ecology	Biology. Eleven of 15 females studied held an egg. The length x width of the eggs ranged from 35 x 35 to 100 x 50 µm. The eggs are not deposited in the substratum but attached to tibiae IV. One-third of the females had a single cocoon fixed with a slender stem, the latter 2 – 3 µm wide. The length of the cocoons was about 103 – 113 µm, the diameter 60 – 64 µm. Each one enclosed a single embryo.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	description	Limnohalacarus species have the excretory material accumulated within an ovoid, compressed body (cf. Walter 1914; Petrova 1966; Ramazotti & Nocentini 1960; Pepato & Dos Santos 2015). In the material studied, 11 (73 %) of 15 females, 9 (22 %) of 27 deutonymphs and one (22 %) of six protonymphs held such a body, but none of four larvae. The body was dorsal to the gut, in some individuals it had a dark centre, surrounded by concentrically arranged more or less transparent layers (Fig. 3 C). In one female the excretory body was almost uniformly dark, in another one hyaline, the body recognizable mainly because refraction of light. In one female (length 255 µm) this body was 108 µm long, 71 µm wide and 41 µm thick, the general size range in length was 95 – 158 µm, in width 50 – 92 µm. The length of the excretory body equalled 0.4 – 0.5 times the length of the female idiosoma. In deutonymphs the stratified body was 60 – 85 µm long, 45 – 95 wide, in a protonymph 50 µm long, 36 µm wide, i. e., a length of 0.3 – 0.4 and 0.2 of that of the nymphal idiosoma, respectively. Such a body was present / absent independent of the age of the instar, e. g. it was absent both in assumedly recently hatched females and in ovigerous ones and also in those carrying a cocoon (or their remnants) fixed to the tibiae.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	discussion	Remarks. Adults of Limnohalacarus cultellatus and L. novus, the two species known from Madagascar, can easily be separated by (1) the shape of the ocular plates, namely OC hardly longer than wide (L: W 1.1: 1) and not including the platelet with a gland pore versus OC 1.3 times longer than wide and including the platelet with gland pore, (2) the ventral plates, separated versus fused to a shield, (3) the length of the gnathosoma, at least 1.5 times longer than wide versus 1.1 times or less, and (4) the claws on tarsus I, with few delicate versus numerous long tines. Juveniles of both species have the ventral plates and the OC and gland-pore bearing platelet separated but can be distinguished by the shapes of gnathosoma and claw I. Compared with African species, L. novus turns out to be most similar to L. portmanni. Both are of about the same size, their length 206 – 289 and 217 – 289 µm, respectively, but the PD of L. novus is not as slender as in L. portmanni and the length ratio PD: AD is 2.6 – 2.7: 1 in L. novus but 3.1 – 3.3: 1 in L. portmanni (Bartsch 2013 a).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC3FFD5F517F9DBFAADA75D.taxon	distribution	Geographical distribution (Fig. 2) (cf. Bartsch 2013 a): Afrotropical Region. – Madagascar; Australian Region. – Australia (Queensland – Moreton Bay, North Stradbroke Island, not Moreton Island).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC5FFD5F560FB64FB42A224.taxon	description	Characters (according to Walter 1935, Green 1984 and Bartsch 2013 a): 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).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC5FFD5F560F9FAFB41A33D.taxon	description	Characters (according to Walter & Bader 1952 and Bartsch 2013 a): 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).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC5FFD5F560F8F2FB94A3F4.taxon	description	Characters (according to Bader 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 slender, its L: W 1.6: 1. Distribution: DR Congo (Zaire) (Lake Tanganyika) (Bader 1968).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD6F6CDFEE5FEDDA64E.taxon	description	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).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD6F6CDFD62FE64A7E3.taxon	description	Characters (according to Bader 1967 and Bartsch 2013 a): 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).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD9F6F3F973FB6BA529.taxon	materials_examined	Collecting data. Central Madagascar, Antananarivo, Anjazorobe, River Ranonisoanavola (larger stream E from main mountain chain), 1200 m asl, 13.2 ° C, 0.058 mS / cm, interstitial, 23 Jul. 2001 (MD 012). – South-eastern Madagascar, Fianarantsoa, Ionilahy, stream draining area Marosaro (S from River Ionilahy), 220 m, 21 ° C, 0.072 mS / cm, interstitial, 12 Aug. 2001 (MD 023). – South-eastern Madagascar, Fianarantsoa, Ionilahy, small stream crossing the railroad east of village, 200 m, 15 Aug. 2001 (MD 027). – South-eastern Madagascar, Fianarantsoa, Andrambovato, stream 3 km E from the village, upstream from the cascade, 900 m, 20 Aug. 2001 (MD 038). – Southern Madagascar, Tulear, Tsimelahy, River Antarantsa, ca 1 km upstream from village, 300 m, 20.4 ° C, 0.171 mS / cm, interstitial, 04 Sep. 2001 (MD 058). – Central Madagascar, Antanarivo, Ankaratra, Reserve Manjakatompo, left affluent of River Mahiavona, EM Mantsina, 1750 m, 14.1 ° C, 0.003 ms / cm, interstitial, 08 Oct. 2001 (MD 107). – Northern Madagascar, Antsiranana, Andapa, right affluent of River Ambendrana downstream, large cascade, 600 m, 11 Nov. 2001 (MD 147).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD9F6F3F973FB6BA529.taxon	description	Short description (Fig. 4 A – E). Female: Length (with frontal spine included) 249 – 304 [25] µm, 228 – 273 (if frontal spine excluded). All Madagascar specimens with frontal spine, spine generally slender (Fig. 4 C) and about 21 – 31 µm long, one female with 19 µm-long spine. Dorsal plates uniformly foveate, foveae 3 µm wide. AD and anterodorsal part of AE fused (Fig. 4 A). Opposing edges of AD and PD truncate. OC oblong, without cornea or eye pigment. Dorsal setae minute, seven pairs present, most posterior pair on PD. Ventral plates AE, PE and GA fused to a shield (Fig. 4 B). A pair of epimeral pores about levelling with aperture of legs II. GO extending anteriad to the level of apertures of legs IV. Area corresponding to PE with one rather short dorsal and two long ventral setae, genital area with four to five pairs of setae. Each genital sclerite with two to three gac. Gnathosoma slender, 1.8 times longer than wide. Rostrum almost extending to end of P- 2 (Fig. 4 D). P- 2 with single dorsal seta, P- 3 with medial spur. Length ratio leg I: idiosoma 0.8: 1, following legs somewhat shorter. Telofemur and genu I equal in length (Fig. 4 E). Telofemora III and IV with 2 / 0 dorsal / ventral setae. Genu I with two ventral setae, generally one seta spur-, the other seta-like, rarely both setae spur-like. Tibia I ventrally with two pairs of setae, one pair spiniform, one bristle-like; ventral flank of tibiae II to IV with (zero to) one smooth and (one to) two pectinate setae. Tarsus I with ventromedial spur, apically with pair of eupathidia (short sensory setae) and pair of doubled pas (Fig. 4 E); tarsus III with 4 / 1 dorsal / ventral setae, and tarsus IV with 3 / 1 setae. Lateral fossa membrane of tarsus I enlarged, its length 7 µm, height 6 µm, on following tarsi lateral and medial fossa membrane small both in length and height. Claws on tarsus I smaller than those of following tarsi. To get an idea of variants in respect to external characters, as commonly found in Lobohalacarus weberi (Bartsch 1995, 2007, 2011), details of 25 uncleared females were examined in a drop of glycerine, but some females were damaged or the characters in question obscured. The character studied were (1) frontal spine: present [25]; (2) number of gac per genital sclerite: 2 [12], 3 [38]; (3) number of pgs in each half of genital plate: 3 [1], 4 [22], 5 [26]; (4) combination of spines (sp) and bristles (br) on genu I: sp / br [49], sp / sp [1]; (5) number of dorsal / ventral setae on telofemur III: 2 / 0 [47], 2 / 1 [1]; (6) number of dorsal / ventral setae on telofemur IV: 2 / 0 [49], 2 / 1 [0]; (7) number of pectinate (p) + smooth (s) setae on tibia II: 2 p + 1 s [46], 1 p + 1 s [4]; (8) number of pectinate (p) + smooth (s) setae on tibia III: 2 p + 1 s [31], 1 p + 1 s [14]; (9) number of pectinate (p) + smooth (s) setae on tibia IV: 2 p + 1 s [48], 1 p + 1 s [0]; (10) number of dorsal / ventral setae on tarsus III: 4 / 1 [43], 4 / 0 [1], 3 / 0 [0]; (11) number of dorsal / ventral setae on tarsus IV: 4 / 1 [1], 3 / 1 [45], 3 / 0 [2]. Male: Not present. Juveniles: Length (frontal spine excluded) of deutonymphs 230 – 247 [3] µm, protonymphs 210 [2] µm and larvae 130 – 162 [4] µm. All instars with slender frontal spine, in one larva that spine very delicate. Ventral plates AE, PE and GA separated. Tarsus I with three dorsal setae, dorsolateral solenidion, enlarged lateral fossa membrane, ventromedial spur, and two ventral eupathidia.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD9F6F3F973FB6BA529.taxon	biology_ecology	Biology. Eighteen of 26 females enclosed an egg, one female two eggs. The smallest egg was globular and had a size of 40 x 40 µm, the largest one reached a size of 110 x 56 µm. No male was found in the material from Madagascar. Though L. weberi is one of the very wide-spread and commonly recorded species reliable records of males are lacking.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD9F6F3F973FB6BA529.taxon	discussion	Remarks. Two easily recognized characters used for identification of Lobohalacarus weberi are the frontal spine and the ventral shield. These characters are known to vary, though rarely. In the samples from Madagascar, all individuals have a pointed frontal spine and a ventral shield. In almost all Madagascan specimens the frontal spine is very slender, similar to that illustrated by Schwoerbel (1955: fig. 1 (4 )). In general, the spine is somewhat shorter but wider (cf. Romijn & Viets 1924: figs 3 and 4; Bartsch 2006: fig. 5 – 8 a and b). Among material from Inaccessible Island, Tristan da Cunha Islands, three out of six females had no frontal spine. In two of these three specimens the anterior margin of the idiosoma was evenly arched, in one the spine was reduced to a hood-like process (Bartsch 1995: figs 12 and 13). Out of 92 individuals from New Zealand, one female had no spine but an evenly rounded anterior margin, 91 females had a frontal spine (Bartsch 2007: fig. 2 A – C). In the same material one of the females had no ventral shield, instead AE, PE and GA were separated (Bartsch 2007: fig. 2 C). Lobohalacarus weberi is expected to be highly variable in its morphology rather than to be represented by several cryptic species. Studies on the influence of habitat parameters on character expression do not exist.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC6FFD9F6F3F973FB6BA529.taxon	distribution	Geographical distribution of Lobohalacarus weberi and the Lobohalacarus weberi complex (Fig. 5) (cf. Bartsch 2008 a, b, 2011, 2014 a; Pešić et al. 2010; Fritz & Feminella 2011; Stolbov et al. 2018): Afrotropical Region. – Kenya – Madagascar – Tristan da Cunha Islands; Palaearctic Region. Europe: – Austria – Belgium – United Kingdom (England, Northern Ireland, Scotland) – Bulgaria – Denmark – Faeroerne – Finland – France – Germany – Greece – Hungary – Iceland – Italy – Macedonia – Monte Negro – Poland – Portugal – Romania – Switzerland – Spain – Sweden – The Netherlands. Northern Africa: – Tunisia. Asia: – Iran – Japan (L. weberi gotoensis — Imamura 1970) – Russia (Tyumen region) – Uzbekistan (Lobohalacarus bucharensis — Jankovskaja 1967); Nearctic Region. – Canada (British Columbia, New Brunswick, Newfoundland, Ontario, Quebec). – United States (Alabama, Arizona, California, Colorado, Georgia, Illinois, New Hampshire, New Mexico, New York, North Carolina, Rhode Island, Tennessee, Virginia); Neotropical Region. – Chile (Magallanes) – Peru (Lake Levandera, Lobohalacarus processifer) – Venezuela (near Higuerote, Lobohalacarus hummelincki); Australian Region. – Australia (New South Wales (Lobohalacarus sp.), Queensland, Victoria (Lobohalacarus bunurong and Lobohalacarus sp.), the author expects these specimens to belong to the L. weberi complex). – New Zealand (North and South Island); Pacific Islands. – Hawaiian Islands.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC9FFDBF517FEA7FBFDA267.taxon	biology_ecology	Biology. Fifteen out of 20 females were ovigerous, the other five held no eggs. The size (length x diameter) of the eggs was between 55 x 63 µm and 88 x 75 µm.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFC9FFDBF517FEA7FBFDA267.taxon	discussion	Remarks. The females in the Madagascan material have five (rarely four) external acetabula on each genital sclerite. In populations from other parts of the world the number of acetabula is known to vary between four and nine (Bartsch 2011). In Europe two varieties are known, P. a. alpinus and P. a. brachypeltatus. Discriminating characters in females are the length of the idiosoma, i. e., 297 – 371 versus 248 – 270 µm, and the position of the GO in relation to length of the GP, namely distance from anterior margin of GO to that of GP about the same versus about half the length of GO, respectively (Viets 1927: fig. 6 versus fig 9; Bartsch 2006: fig. 5 - 9 b versus fig. 5 - 10 a). Similar, nymphs of P. a. alpinus have, in contrast to P. a. brachypeltatus, a larger distance between the area with genital acetabula and the anterior margin of GP. A rather inconspicuous difference is that the PD of P. a. alpinus is slightly longer than that of P. a. brachypeltatus. In the first mentioned the ds- 3 insert immediately adjacent or in the margin of the PD, in the latter within the narrow band of striated integument. The Madagascan individuals belong to P. a. alpinus. In general, all adults in populations of P. alpinus are females. The above mentioned male is one of the very rare exceptions. A former record of a male is one of P. a. brachypeltatus. It was found among more than 2500 slide-mounted adults, all extracted from a population living in Northern Germany which inhabited a small former peat ditch, now filled with rapidly growing Sphagnum sp. (Sphagnales) (Bartsch 1987). The water in the peat ditch was acidic, had a low ionic concentration and a sparse fauna (some few cladocerans, rotifers and testaceans). Differences between the males, from Madagascar (P. a. alpinus) and northern Germany (P. a. brachypeltatus), are the larger size, 286 µm versus 254 µm, and a higher number of pgs, namely 39 versus 20 pgs. The morphological differences between the two forms P. a. alpinus and P. a. brachypeltatus raises the question whether these are two separate species, subspecies or ecotypes? In northern Europe, Porohalacrus a. alpinus inhabits a wide range of substrata, slightly acidic to alkaline and even oligohaline brackish water, oligo- and mesotrophic lakes, ponds and banks of slow flowing rivers, substrata rich in microcaverns, e. g. dense colonies of small mussels (Dreissena sp.), colonies of sponges, bryozoans, mosses, and biofilms on vascular plants, all these habitats have a rich meio- and microfauna and - flora. In contrast, P. a. brachypeltatus has been taken only in strongly acidic Sphagnum peats with sparse associated meiofauna. Judging by the gut content of P. a. alpinus, namely brownish, with darker and lighter particles, these mites are carnivorous. In contrast, the gut content of P. a. brachypeltatus is greenish, suggesting that the mites are phytophagous. Is P. alpinus brachypeltatus a degenerate (impoverished) form, because of its life in an environment with low concentration of cations and meagre diet? Both molecular and experimental studies, namely rearing of the mites over several generations under different environmental conditions, may give an answer. Phenotypic plasticity in freshwater crustacea has been documented more than a century ago (Woltereck 1909), and plasticity is not restricted to arthropods, Cattau et al. (2018) recently described a rapid morphological change in a bird of prey. Geographical distribution (Fig. 7) of both P. a. alpinus and P. a. brachypeltatus (Viets 1956; Green & MacQuitty 1987; Bartsch 2007, 2009, 2011; Tolstikov et al. 2005; Semenchenko et al. 2010; Stolbov et al. 2018; Pepato & da Silva Conceição 2019 in press): Afrotropical Region. – Madagascar (new record); Palaearctic Region. Europe: – Austria – Belgium – Great Britain (England, Scotland, Wales) – Denmark – Finland – France – Germany – Hungary – Iceland – Italy – Norway – Poland – Russia (Saratov — Volga Biological Station) – Sweden – Switzerland – The Netherlands – Ukraine. Northern Africa: – Algeria. Asia: – Turkey – Russia (Kamchatka, Sakha Republic, Tyumen region); Australian Region. – Australia (Western Australia — Esperance). – New Zealand (North Island). Nearctic Region. – United States (New Hampshire, Rhode Island). – Canada (Ontario, Quebec); Neotropical Region. – Brazil (Rio Grande do Sul — Porohalacarus cf. alpinus).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCBFFDFF517F995FEA9A10D.taxon	description	Short description (Fig. 8 A – G). Female: Length 203 – 245 [30] µm, idiosoma pale, about 1.8 times longer than wide, its anterior and posterior part narrowed. Eye pigment lacking. AD and PD fused to an elongate dorsal shield (Fig. 8 A). Ventral shield extending dorsad and including AE, PE, GA (Fig. 8 B) and parts corresponding to OC. Integument of dorsal shield with delicate porosity and faint foveate ornamentation, ventral plates almost smooth. Dorsal setae very small, ds- 1, ds- 3 and ds- 4 in dorsal shield, ds- 2 in dorsal part of ventral shield. Adanal setae lacking. Gland pores lacking. Area of ventral shield representing AE with two pairs of marginal and one pair of ventral setae, areas of PE each with one marginal and one ventral seta, and that of GP with two perigenital setae. Marginal setae of idiosoma longer than ventral setae. Three pairs of genital acetabula arranged in posterior part of genital sclerites. Gnathosoma slightly wider than long (Fig. 8 C). Palps four-segmented, extending beyond short, conical rostrum. Short palps and rostrum visible in dorsal aspect. Legs distinctly shorter than idiosoma (length ratio leg I: idiosoma equalling 0.5: 1). Distance between apertures of pairs of legs II and III almost equal to half the length of idiosoma (in the other genera length of idiosoma more than twice the distance between these apertures). Trochanter I in one of the females studied with delicate medial seta, in general no seta present. Ventral setae on genu I and three ventral setae on tibia I bipectinate (Fig. 6 D). Male: Not present. Juveniles: Length of deutonymph 173 – 226 µm [6], of protonymph 122 – 173 µm [3], of larva 113 – 128 µm [2]. Nymphs with AD and PD separated by striated integument, remnants of ocular plates and marginal part of epimeral plates fused. Ventral plates AE, PE and GP fused to a single ventral shield, no fissure between area representing AE and GP. Ventral plates delicate; ornamented with foveae. In both nymphal instars area representing AE with three pairs of setae (Fig. 8 E and F). In deutonymph area representing PE with one pair of marginal and one of ventral setae (Fig. 8 F) and area of GP with one pair of pgs. Protonymphal PE solely with pair of marginal setae. Larval tarsus III, just as tarsi III of following instars, with three dorsal setae, namely two fossary setae and one solenidion (Fig. 8 G).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCBFFDFF517F995FEA9A10D.taxon	biology_ecology	Biology. Of 32 females studied 13 (41 %) were ovigerous. In general a single egg was present, its size (length x diameter) between 45 x 43 µm and 70 x 43 µm.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCBFFDFF517F995FEA9A10D.taxon	discussion	Remarks. As illustrated in Bartsch (2013 b: fig. 2 e), AD and PD of the deutonymphs, as also those of the protonymphs, are separated from each other by a narrow, transverse area of striated integument, but both deuto- and protonymphs have a ventral shield, including the anterior and posterior epimeral and the genital plate (AE, PE and GP). In contrast to Bartsch (2013 b: fig. 2 f, 2 g), no transverse rupture was recognized in the new material studied (three deutonymphs, one protonymph). In the majority of halacarids the adults have solid exoskeletal plates. In several species these are fused to a dorsal or ventral shield. Sometimes, though rarely, both the dorsum and venter are covered by a solid shield whereas the juveniles have the plates separated by tensible striated integument. Consequently juveniles can grow due to expansion of the striated integument between the dorsal and the ventral plates (as illustrated in Halacarellus subterraneus — Bartsch 1972 fig. 28 A, B versus C, D and E, F versus G, H) whereas the adults can hardly increase in size. An exception is Ropohalacarus pallidus. In the juveniles of this species, the foveate textured integument of the ventral plates is expected to allow a slight dilatation (cf. Bartsch 2013 b). Data on the thickness of the pro- and epicuticula are lacking. No males have ever been found, neither of Ropohalacarus pallidus nor of the second species, namely R. uniscutatus, but the number of specimens studied to date is small (<50 individuals). Compared with other Madagascar halacarids, R. pallidus is in its general shape most similar to Porohalacarus alpinus. Distinguishing characters are: the pale idiosoma (versus prominent spots of eye pigment), the dorsal and ventral shield (versus dorsum with AD, OC and PD, venter with AE, PE and GP), the ornamentation of dorsal shield or plates, delicately foveate versus reticulated with longitudinal polygons, the position of apertures of legs III, in posterior third of idiosoma (0.7) versus in its middle (0.5). Geographical Distribution (Fig. 9): Afrotropical Region. – Madagascar (Bartsch 2013 b and present record).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCFFFC0F689FABCFAD3A16E.taxon	materials_examined	Collecting data. Central Madagascar, Antananarivo, Anjazorobe, River Ranonisoanavola (larger stream E from main mountain chain), 1200 m asl, 13.2 ° C, 0.058 mS / cm, interstitial, 23 Jul. 2001 (MD 012). – South-eastern Madagascar, Fianarantsoa, Andrambovato, stream 3 km E from the village, upstream from the cascade, 900 m, 20 Aug. 2001 (MD 038). – Southern Madagascar, Tulear, Tsimelahy River Antarantsa, ca 1 km upstream from village, 300 m, 20.4 ° C, 0.171 mS / cm, interstitial, 04 Sep. 2001 (MD 058). – Central Madagascar, Antananarivo, Ankaratra, Reserve Manjakatompo, left affluent of River Mahiavona, EM Mantsina, 1750 m, 14.1 ° C, 0.003 ms / cm, interstitial, 08 Oct. 2001 (MD 107).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCFFFC0F689FABCFAD3A16E.taxon	description	Short description (Fig. 10 A – G). Female: Length 270 – 335 µm [8]. With faint spots of brown eye pigment in anteromedian part of AD and anterior part of OC (Fig. 10 A). AD, OC and PD with reticulate ornamentation, reticulation most distinct within pair of faint costae of PD. Pairs of glp- 1 to glp- 5 and ds- 1 to ds- 4 as illustrated, ds- 5 lacking, ds- 6 on anal cone. Delicate punctation of ventral plates presenting reticulate pattern. AE, PE and GP separated. AE with pair of epimeral pores (Fig. 10 B). Each PE with one ventral and lateral but no dorsal seta. Gnathosoma somewhat wider than long (Fig. 10 D). Pair of palps attached dorsally, distance between P- 1 less than their width (Fig. 10 C). P- 2 somewhat flattened, length 1.3 times the height (Fig. 10 E); basal seta on P- 2 short; spiniform, distal seta long and slender. P- 3 with large medial spine, its length 0.9 of that of P- 3. P- 4 ending with a similar wide spine. Legs shorter than idiosoma, length of legs I and IV about 0.6 and 0.7 times that of idiosoma, respectively. Length of telofemur I 1.5 times the height. In addition to long, slender setae, telofemur, genu and tibia of leg I with 2, 2 and 1 short and spiniform dorsal setae and 0, 2, 2 long ventral spines, respectively. Pair of ventral spines on genu I distinctly, on tibia I faintly bipectinate. Claws I with solid, mushroom-like arranged tines (Fig. 10 F), tines on claws on following tarsi in J-shaped arrangement. Male: Not present. Juveniles: Length of deuto-, protonymphs and larvae 205 – 285 [8], 180 – 255 [7] and 143 – 148 µm [2], respectively.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCFFFC0F689FABCFAD3A16E.taxon	biology_ecology	Biology. Of eight females studied six held eggs. Size of eggs 10 x 10 to 40 x 45 µm (length x diameter). If present, the excretory material is in form of small, brown globuli. These are concentrated within a rod-like structure (Fig. 10 G).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCFFFC0F689FABCFAD3A16E.taxon	discussion	Remarks. Soldanellonyx monardi is presently the only Soldanellonyx species recorded from the Afrotropics. Soldanellonyx chappuisi Walter, 1917 and S. visurgis Viets, 1959, as S. monardi reported from several continents, have as yet not been taken but are expected to be found in future studies in Africa or the Afrotropical region. Soldanellonyx chappuisi and S. visurgis have, in contrast to S. monardi, more slender telofemora I (length more than 1.5 times the height), four ventral bristles or spines on tibia I (versus two), more slender and longer P- 2 (length more than twice the height) and the two dorsal setae on P- 2 are similar-sized (versus basal seta less than half the length of distal seta). In addition, no epimeral pores are seen in S. chappuisi and S. visurgis but these are present in S. monardi. Another six Soldanellonyx species are described, one species has been collected in both southern Japan and Kamchatka, each one of the others from a single geographical region, four from Japan, one from the Lake Baikal. In Soldanellonyx monardi, as also in S. chappuisi and S. visurgis, males are extremely rare or absent. Those recorded by Sokolov (1952), Efford (1959) and Imamura (1981) need confirmation. The author expects the males of S. monardi to differ from females by a high number (> 20) of pgs arranged around the GO and, of course, the presence of the spermatopositor. Slight differences in the outline of the GA, as described by Sokolov (1952) and Imamura (1981), are commonly found in females. Sokolov (1952: fig. 91,4) presented an illustration of a male GA with a slightly larger number of genital acetabula (11 – 12 pairs) and pgs (5 – 6 pairs) but else similar to that of females, the typical spermatopositor is not illustrated. Imamura (1981) described the ‘ penis skeleton’ as having four hook-shaped claws; the number of the genital acetabula is similar to that of females. Hook-shaped claws on the spermatopositor are else unknown in halacarid males and those mentioned by Imamura (1981) may represent the genital spines of an ovipositor. Efford (1959) did not present any morphological details.	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
03F38B72FFCFFFC0F689FABCFAD3A16E.taxon	distribution	Geographical distribution (Fig. 11) (of S. monardi and its subspecies) (Fig. 8) (Bartsch 2008 a, 2011, 2014 a; Tolstikov et al. 2005; Pešić et al. 2010; Stolbov et al. 2018; Pepato & da Silva Conceição, in press): Afrotropical Region. – Kenya – Madagascar; Palaearctic Region. Europe: – Austria – Belgium – United Kingdom (England, Northern Ireland, Scotland, Wales) – Bulgaria – Crimea – Croatia – Denmark – Faeroerne – Finland – France – Germany – Hungary – Iceland – Italy – Luxemburg – Macedonia – Monte Negro – Portugal – Romania – Russia (Karelia, Kola Peninsula, Lake Onega) – Switzerland – Spain – Sweden – The Netherlands. Northern Africa: – Tunisia. Asia: – Japan – Russia (Kamchatka, Tyumen region); Oriental Region. – Indonesia (Java) – Vietnam; Australian Region. – Australia (New South Wales, Queensland). – New Zealand (North Island); Pacific Islands. – Hawaiian Islands; Nearctic Region. – Canada (British Columbia, Manitoba, New Brunswick, Newfoundland, Ontario, Quebec). – United States (Alabama, Arizona, California, Georgia, Indiana, Missouri, New Hampshire, New York, North Carolina, Missouri, Oregon, Pennsylvania, Rhode Island, Texas, Tennessee, Virginia). The Soldanellonyx species, by Vinke (2013) mentioned from the Northwest Territories (Canada), may belong to S. monardi (in Fig. 11 marked by a question mark); Neotropical Region. – Brazil (Sao Paulo) – Chile (Magallanes) – Falkland Islands (Malvinas).	en	Bartsch, Ilse (2018): Freshwater halacarid mites (Acari: Halacaridae) from Madagascar - new records, keys and notes on distribution and biology. Bonn zoological Bulletin 67 (2): 79-99, DOI: 10.20363/BZB-2018.67.2.079, URL: http://dx.doi.org/10.20363/bzb-2018.67.2.079
