Mamersella thienemanni K. Viets, 1929

Goldschmidt, Tom, 2008, Taxonomical, ecological and zoogeographical studies on anisitsiellid water mites (Acari: Hydrachnidia: Anisitsiellidae Koenike, 1910) from Madagascar, Zootaxa 1954 (1), pp. 1-120 : 59-69

Mamersella thienemanni K. Viets, 1929

( Figs 123 –159, Table 7, 8)

Material examined: MD 33 , Madiorano (Fianarantsoa), spring at right border of stream crossing the railroad at km 51.2 ( MD 31 ), 650 m asl, 17.0 °C, 53 µS/cm, 18.08.2001, 1/1/0 mounted, 1/2/0 unmounted ; MD 36 , Andrambovato (Fianarantsoa), spring brook 0.5 km south-east from the 1.07 km-railway-tunnel, 900 m asl, 16.1 °C, 35 µS/cm, 19.08.2001, 0/1/0 mounted, 0/1/0 unmounted ; MD 45 , Andrambovato (Fianarantsoa), riparian spring at stream east railway-tunnel 4 (about 1 km west of the village), 800 m asl, 16.5 °C, 47 µS/cm, 22.08.2001, 2/1/0 mounted, 2/0/0 unmounted ; MD 63 a, Andohahela (Tulear), Isaka , stream exposition west 1 km north from the village, riffle, 250 m asl, 19.7 °C, 136 µS/cm, 07.09.2001, 2/2/0 mounted, 2/3/0 unmounted ; MD 68 , Andohahela (Tulear), Fenoevo , first spring north pass RIP 118, 700 m asl, 08.09.2001, 1/ 1/1 mounted, 1/1/1 unmounted ; MD 71 b, Andohahela (Tulear), Isaka , spring area south pass RIP 118 (km 36), spring brook, 700 m asl, 16.0–18.4 °C, 55–60 µS/cm, 10.09.2001, 1/2/0 mounted, 1/0/0 unmounted ; MD 109 , Ankaratra (Antananarivo), Reserve Manjakatompo , riparian spring exposition south-east at spring brook north deviation to Analamitana ( MD 108 ), 1850 m asl, 14.3 °C, 3 µS/cm, 08.10.2001, 1/2/1 mounted, 2/2/0 unmounted ; MD 137 , Marofototra (Antalaha, Antsiranana), rheocrene exposition south, north Antanambazaha , 100 m asl, 24.2 °C, 8 µS/cm, 05.11.2001, 1/1/0 mounted, 1/2/0 unmounted ; MD 139 , Marofinaritra (Antalaha, Antsiranana), spring north the path about 1 km south-west Marofototra , 70 m asl, 24.0 °C, 14 µS/ cm, 05.11.2001, 0/1/0 mounted, 0/1/0 unmounted ; MD 141 , Andranomifototra (Andapa, Antsiranana), Tanambao , rheocrene near km 27 Route Nationale 3b, 140 m asl, 22.9 °C, 6 µS/cm, 09.11.2001, 4/3/0 mounted, 5/ 4/0 unmounted ; MD 143 , Andapa (Antsiranana), riparian springs at Rivière Masiaposa (crossing Route Nationale 3b at km 5–6), 700 m asl, 20.8 °C, 10 µS/cm, 10.11.2001, 4/2/0 mounted, 2/4/0 unmounted ; MD 148 , Andapa (Antsiranana), rheocrene near km 1 of Route Nationale 3b to Sambava , 600 m asl, 20.8 °C, 14 µS/cm, 11.11.2001, 2/3/1 mounted, 0/6/4 unmounted ; MD 154 , Joffreville (Montagne d’Ambre, Antsiranana), Rivière de Manques in Reserve Fontenay , 550 m asl, 21.9 °C, 25 µS/cm, 17.11.2001, 2/0/1 mounted, 0/1/0 unmounted ; MD 156 , Joffreville (Montagne d’Ambre, Antsiranana), rheocrene at right tributary Rivière de Manques in Reserve Fontenay , 610 m asl, 21.2 °C, 25 µS/cm, 18.11.2001, 1/1/1 mounted, 1/1/2 unmounted ; MD 157 , Joffreville (Montagne d’Ambre, Antsiranana), riparian springs at right tributary Rivière de Manques in Reserve Fontenay , 650 m asl, 21.5 °C, 28 µS/cm, 18.11.2001, 7/12/2 mounted, 35/19/7 unmounted ; MD 160 , Joffreville (Montagne d’Ambre, Antsiranana), riparian springs at right border of Rivière Antomboka downstream sacred cascade, 1000 m asl, 18.0 °C, 20 µS/cm, 19.11.2001, 5/6/0 mounted, 12/10/0 unmounted ; MD 161 , Joffreville (Montagne d’Ambre, Antsiranana), riparian springs at Rivière de Manques in Reserve Fontenay , 730 m asl, 20.9 °C, 11 µS/cm, 20.11.2001, 4/12/2 mounted, 26/15/3 unmounted ; MD 162 , Joffreville (Montagne d’Ambre, Antsiranana), Rivière de Manques in Reserve Fontenay , 730 m asl, 21.5 °C, 15 µS/ cm, 20.11.2001, 0/1/0 mounted ; MD 164 , Joffreville (Montagne d’Ambre, Antsiranana), riparian springs at Rivière de Manques in Reserve Fontenay , 580 m asl, 21.0 °C, 31 µS/cm, 20.11.2001, 3/8/2 mounted, 3/6/0 unmounted ; MD 166 , Joffreville (Montagne d’Ambre, Antsiranana), spring brook at right border of Rivière Antomboka downstream large cascade, 850 m asl, 20.4 °C, 24 µS/cm, 21.11.2001, 1/2/0 mounted, 0/1/0 unmounted ; MD 167 , Joffreville (Montagne d’Ambre, Antsiranana), riparian rheocrenes at Rivière Antomboka downstream large cascade, 850 m asl, 20.8 °C, 24 µS/cm, 21.11.2001, 7/9/1 mounted, 13/18/0 unmounted .

Habitat: Mainly springs (some streams and spring brooks) at 70–1850 (mainly 500–1000) m asl.

Distribution: Indonesia, India, Madagascar (mainly northern mountain ranges and Montagne d’Ambre, also Eastern slope, Central and southern mountain ranges).

Diagnosis (Malagasy specimens): Idiosoma rounded-oval; large dorsal plate bears post-ocular setae, Dgl- 3 to -5 (in some specimens also Dgl-6) and Lgl-4; soft, lined integument beside dorsal plate bears Dgl-2, Lgl- 1 to -3, Vgl-2 to -4 (in some specimens also Dgl-6), three pairs of small platelets and five pairs of lyrifissures; ventral shield antero-dorsally (mostly) surpassing anterior coxae; Cx-I fused medially; caudal margin of Cx- IV surpassing genital field; excretory pore clearly on ventral shield; genital field elongated oval in male, more compact rectangular-oval in female, acetabula elongated-oval, touching each other; legs stout, leg-IV with many heavy setae; claws of leg-I to -III simple; capitulum compact, rostrum short; palp relatively compact; chelicera slender.

Description, Malagasy males (n = 7): Idiosoma rounded-oval ( Figs 123 , 131 ); heavy sclerotized body parts very pale greyish-purple; dorsum mainly covered by large, irregular oval plate (L/W 530-625/347-420), in a curved row including Dgl-3, -4, -5, Lgl-4 – and at posterior margin of most specimens Dgl-6; post-ocular setae slightly medial between Dgl-3 and -4 ( Figs 124 , 132 ); in lined, soft integument around dorsal plate: Dgl- 2 anterior, Lgl-1 to -3 lateral and Vgl-2 to -4 latero-caudal, furthermore three pairs of small platelets (lateral Dgl-2, lateral dorsal plate between Lgl-4 and Vgl-3 and latero-caudal Dgl-6) and five pairs of lyrifissures (posterior small anterior platelets, posterior Lgl-1, between Lgl-2 and -3, Vgl-3 and -4, Vgl-4 and -2); lateral eyes oval, separated on both sides (often lost in preparation), lying free under integument ( Figs 124 , 132 ); large trapezoid frontal plate bearing Dgl-1 and pre-ocular setae ( Fig. 125 ); venter completely sclerotized, forming unified ventral shield with margins of coxae still visible (L/W 641-693/467-693); Cx-I medially fused in caudal half; medial margins of Cx-III slightly convex, approximate; Cxgl-2 far medial, between Cx-II and Cx-III; Cxgl-4 centrally in medial third of Cx-III ( Figs 123 , 131 ); medial margin of Cx-IV concave, forming very narrow genital bay, caudal margin rounded, caudally extending well beyond genital field, latero-caudally convex curved towards insertions of legs-IV, lateral margin reaching dorso-laterally up to area of Cx-II; Cx-IV anterior to insertion of legs-IV in some specimens with small ridge ( Fig. 131 ); genital field elongated, anteriorly tapering, lateral margins straight, anteriorly and posteriorly smoothly rounded; not reaching caudal margin of Cx-IV; acetabula mid-sized, elongated-oval, touching each other, Ac3 smaller than Ac1 and Ac2, Ac1 and Ac3 slightly distant from anterior and posterior margins of genital flaps ( Figs 123 , 131 ); setae of Vgl- 1 latero-caudal to genital field, close to medio-caudal margin of Cx-IV, within genital bay ( Figs 123 , 131 ); excretory pore incorporated in ventral shield ( Figs 123 , 131 ); genital skeleton relatively slender, brachia distalia slender, oblique, brachia proximalia stronger, distally extend, oblique ( Figs 126 , 133); legs strong, bearing several heavy setae; leg-I to -III with well developed slender claws without clawlets, leg-II in most specimens with several long, thin hair-like setae, leg-I-6 and leg-II-6 distally extend, ventro-distally with many short hair-like setae ( Figs 127 , 134, 135), leg-IV-4 to -6 ventrally with regular rows of strong setae, leg-IV-6 distally tapering (Figs 128, 136, 137); capitulum compact (in some specimens more elongate ( Table 7)), rostrum very short (Fig. 138); chelicera with slender, sharply pointed claw, basal segment with slight dorsal hump (Figs 130, 139, 140); palps relatively compact, P1 without dorsal setae, P2 with pinnate, ventro-lateral seta, six dorsal setae, P3 with two lateral and two medio-dorsal setae, P4 relatively slender, distally tapering, ventral setae beside small protrusion, P5 relatively compact (Figs 129, 138, 141).

Female (Malagasy specimens, n = 11): Idiosoma larger than in male ( Figs 144 , 150 ); dorsal plate variable in size (L/W 546–730/373–525), in most specimens Dgl-6 not fused with dorsal plate ( Figs 145 –147, 151); ventral shield in most specimens more rounded (L/W 651–845/567–809); genital field more compact ( Figs 144 , 150 , Table 7); legs and gnathosoma similar to males (Figs 148, 149, 152, 153).

description by K. Viets (1929)) and for M. maryellenae Cook, 1967 from India (taken from the species description by

Cook (1967)). Measurements given in µm.

Deutonymph (n = 3): Idiosoma very similar to adults, rounded-oval (Fig. 154); large dorsal plate irregular, elongated-oval (L/W 441–473/278–326), bearing Dgl-3 to -5; soft, lined integument around dorsal plate slightly broader than in adults, dorsal plate surrounded by Dgl-2, Lgl-1 to -4 and Dgl-6 (from anterior to caudal), further latero-caudal Vgl-2 to -4, furthermore five pairs of lyrifissures; two pairs of lateral eyes on each side separated under integument (Fig. 155); ventral shield complete, rounded (L/W 536-620/483-578); coxal field very similar to adults; provisional genital field as in adults closely fit in genital bay between Cx-IV, two pairs of acetabula, laterally with three pairs of setae and central bifurcate sclerite (Fig. 154, Table 7); setae of Vgl-1 posterior caudal margin of Cx-IV; excretory pore on ventral shield, close to caudal margin; legs and gnathosoma similar to adults, however bearing less setae (Figs 156, 157); capitulum compact (Fig. 158), P2 with three dorsal setae, without ventral seta, P4 slender, with ventral setae in distal half on small protrusions (Figs 158, 159).

Remarks: Mamersella thienemanni K. Viets, 1929 is widespread in Southern Asia; originally the species has been collected in springs, a river and a seepage area in Java, Sumatra and Bali, respectively (K. Viets 1935), and has been found again on Java ( Lundblad 1971) and in a well in India ( Panesar 2004). In Madagascar it is by far the most abundant anisitsiellid species, representing 71 % of all specimens in this study. The species was found in all regions of Madagascar, especially in springs where it is the most common and abundant species. The investigation of extensive material from springs and streams in various parts of Madagascar showed a great variability in the degree of fusion of the dorsal glandularia and small platelets with the main dorsal plate (the fusion of Dgl-6 is mainly subject to sexual dimorphism (fused mostly in males), beside this there are individual differences in the size of the main dorsal plate (reaching close to the Lgl-1 to - 4 in some specimens, even including Lgl-3 on one side in one specimen (Fig. 147), therefore also the number of small platelets surrounding the main dorsal plate is variable; generally the outline of the dorsal plate is irregular (see especially Figs 145 –147)). Furthermore the length of the gnathosoma is remarkably variable (vL 165–190 in males, 178–215 in females).

The type specimen of M. thienemanni (SMF, Viets-Collection, slide number 2732) differs only very slightly from the Malagasy specimens in a slightly slenderer genital skeleton ( Fig. 142 ) and leg-IV-2 ventrodistally bearing two large setae instead of one ( Fig. 143 ). Nevertheless it seems reasonable to assign the Malagasy specimens to M. thienemanni . A second species of the genus — M. maryellenae Cook, 1967 — was described from a cataract and a small river in India ( Cook 1967). The differentiation of M. maryellenae from M. thienemanni had been based upon the following characters: Genital field larger, reaching caudal margin of Cx-IV (in M. thienemanni caudal margin of Cx-IV is extended further posterior); excretory pore in an indentation of the ventral shield (fused with the ventral shield in M. thienemanni ); fusion of Dgl-6 with caudal margin of dorsal plate (glandularia not fused, lying directly posterior dorsal plate in M. thienemanni ). These character states are present in the Malagasy specimens in great variation and therefore have to be excluded from the differential diagnosis of M. maryellenae . Mamersella thienemanni seems to be a very widespread and variable species. A deutonymph originally described as M. thienemanni by K. Viets (1935) might rather be regarded as the deutonymph of Bandakia orientalis K. Viets, 1935 . The latter species was found in the same sample and the described specimen shows the characteristic provisional genital field of the deutonymph of Bandakia ( Panesar 2004) . The deutonymph of M. thienemanni — collected in Madagascar now — is described above and shows character states that fit well with Mamersella thienemanni .

Figures

FIGURES 123–127. Mamersella thienemanni K. Viets, 1929, male (MD 143). 128–130. Mamersella thienemanni K. Viets, 1929, male (MD 161): 123, idiosoma, ventral view; 124, idiosoma, dorsal view; 125, frontal plate; 126, genital skeleton, antero-lateral view (slightly distorted); 127, leg-II; 128, leg-IV; 129, right palp, medial view; 130, chelicera, lateral view. Scale bars = 100 µm.

FIGURES 131, 132. Mamersella thienemanni K. Viets, 1929, male (MD 45). 133. Mamersella thienemanni K. Viets, 1929, male (MD 154b). 134–137. Mamersella thienemanni K. Viets, 1929, male (MD 160). 138–141. Mamersella thienemanni K. Viets, 1929, male (MD 161): 131, idiosoma, ventral view; 132, idiosoma, dorsal view; 133, genital skeleton, anterior view; 134, leg-II, posterior view; 135, leg-II anterior view; 136, leg-IV, posterior view; 137, leg-IV, anterior view; 138, capitulum with left palp, lateral view; 139, chelicera, lateral view; 140, chelicera medial view; 141, right palp, medial view. Scale bars = 100 µm.

FIGURES 144, 145. Mamersella thienemanni K. Viets, 1929, female (MD 164). 146. Mamersella thienemanni K. Viets, 1929, female (MD 109). 147–149. Mamersella thienemanni K. Viets, 1929, female (MD 157): 144, idiosoma, ventral view; 145–147, idiosoma, dorsal view; 148, capitulum with left palp and chelicera, lateral view; 149, right palp, medial view. Scale bars = 100 µm.

FIGURES 150–153. Mamersella thienemanni K. Viets, 1929, female (MD 161): 150, idiosoma, ventral view; 151, idiosoma, dorsal view; 152, capitulum with left palp and chelicera, lateral view; 153, right palp, medial view. Scale bars = 100 µm.

FIGURES 142, 143. Mamersella thienemanni K. Viets, 1929, male (SMF 2732). 142, genital skeleton, anterior view; 143, leg-IV (first segment slightly broken). Scale bar = 100 µm.