Platymamersopsis (s. str.) voanjo, Goldschmidt, 2008

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 : 95-98

Platymamersopsis (s. str.) voanjo sp. nov.

( Figs 224–232 , Table 11)

Type: Holotype female, MD 78 a, Fort Dauphin (Tulear), Mandena ( QMM area), Rivière Amendano 0.5 km upstream road bridge, riffle, 12 m asl, 23.2 °C, 154 µS/cm, 13.09.2001, mounted.

Habitat: Lowland river in coastal forest at 12 m asl.

Distribution: Madagascar (Fort Dauphin, Mandena).

Derivatio nominis: Voanjo (Malagasy) — peanuts; as the characteristically short and rounded leg segments (especially the terminal segments of leg-I and -II) reminiscent of the shape of peanuts.

Diagnosis: Idiosoma small, oval; ridge on dorsal shield posteriorly indistinct; coxal field anteriorly protruding, medial margins of Cx-I and -III relatively short; Cxgl-2 near posterior margin of Cx-II, far lateral; Cxgl-4 central at anterior margin of Cx-III; Cx-IV small; genital field large, caudally far surpassing genital bay; acetabula small, oval; legs compact, claws on leg-I to -III with distinct, single ventral and dorsal clawlet; leg-IV stout, with long setae, with two mid-sized terminal setae, three large sub-terminal setae; capitulum compact, rostrum short; palp compact, ventral margin of P2 concave with strong latero-distal protrusion.

Description, female (n = 1): Idiosoma oval, slightly drop-shaped ( Fig. 224 ), purple-greyish; dorsal shield oval, anteriorly tapering (L/W 397/275), Dgl-3 to -5 with stronger setae, Dgl-6 and Lgl-4 with small setae; dorsal shield centrally with large pores, peripheral ridge anteriorly strongly tapering, posteriorly indistinct, caudal margin not visible; soft integument in dorsal furrow lined, extended over margin of dorsal shield ( Fig. 225 ); ventral shield broad-oval (L/W 451/319); coxal field small, anteriorly surpassing idiosoma; medial margin Cx-I mid-sized (47), Cx-III short (29) ( Fig. 224 ); Cxgl-2 relatively lateral, near posterior margin of Cx-II, Cxgl-4 central at anterior margin of Cx-III; Cx-IV small, nearly triangular, caudally bluntly pointed, caudolateral margins steeply directed towards anterior, lateral ridge slightly curved ( Fig. 224 ); genital field large, broad rectangular-oval (L/W 115/105), anteriorly truncated, laterally convex, tapering towards posterior, caudally truncated, extended far beyond genital bay; acetabula small, oval (Ac1 and Ac3 far remote from anterior and caudal end of genital flaps respectively, Ac1 and Ac2 not touching each other), setae on genital flaps tiny, short ( Fig. 224 ); setae of Vgl-1 lateral to genital field, Vgl-3 lateral of latero-caudal margin of Cx-IV; excretory pore and Vgl-2 close to caudal margin of ventral shield, Vgl-4 at caudo-lateral margin; Lgl-1 to - 3 in lateral margin ( Fig. 224 ); legs short, compact with many elongated, spine-like setae, claws on leg-I to -III strong, curved, with moderate dorsal and ventral clawlet ( Figs 226-228 ); leg-III slenderer than leg-I and -II ( Fig. 228 ); leg-IV very stout with many long and heavy setae, segments distally broad, terminal segment compact, broad, distally strongly tapering, rhombic with two mid-sized terminal setae and three strong, spine-like subterminal ventral setae ( Fig. 229 ); capitulum compact with relatively short rostrum, ventral margin nearly straight ( Fig. 230 ); palp compact; P2 with four dorsal setae and one medio-dorsal seta, dorsal margin curved; ventral margin concave, ventro-medial with strong distal projection ( Figs 231, 232 ); ventral seta slender, inserted lateral of projection; P3 with two medio-dorsal setae and one latero-dorsal seta; P4 ventrally smooth, with small ventro-distal protrusions, ventral setae distally; P5 compact with strong distal claws ( Figs 231, 232 ).

Male: Unknown.

Remarks: The new species Platymamersopsis (s. str.) angulatus , P. (s. str.) loharano and P. (s. str.) voanjo are similar to the nine species described from Africa that share the characteristic of simple dorsal and ventral clawlets on leg-I to -III. All other species from Madagascar, as well as the two species known from India, bear comb-like ventral clawlets. Platymamersopsis (s. str.) loharano is distinct from most African (and all other Malagasy) species due to its elongated slender idiosoma and large, elongated genital field. The only species with a similarly slender idiosoma, P. vietsi Cook, 1966 from Liberia, has a smaller genital field, a shorter ventral seta at P2 and compacter distal segments of leg-I and -IV ( Fig. 233 , see also Cook 1966). Platymamersopsis (s. str.) angulatus is distinct from most African (and Malagasy) species due to its very small genital field and the characteristic lateral protrusions of the venter. The only African species with a similar small genital field is P. chutteri K.O. Viets, 1981 from South Africa; however in that species the coxal field is very small, the P2 is very large (and differently shaped) and P3 and P4 are smaller. The proportions of leg-IV-6 are also similar in these two species, although P. chutteri bears several large sub-terminal setae ( Fig. 234 ) not present in P. (s. str.) angulatus . Platymamersopsis (s. str.) voanjo is primarily characterised by short and compact legs, as well as a large genital field combined with a small coxal field. Slightly similar characters of the venter are found in four species from West and South Africa: P. similis Cook, 1966 , P. agnewi K.O. Viets, 1981 , P. nordenskioeldi K. Viets, 1914 and P. liberiensis Cook, 1966 . The latter three differ in longer and slenderer distal leg segments ( Figs 235-237 ; see also Cook 1966), whereas the distal leg segments of P. similis are as compact as in P. (s. str.) voanjo ( Fig. 238 ). The new species from Madagascar nevertheless is clearly differentiated by its slenderer idiosoma and characteristic medio-ventral projection at P2 (see also Cook 1966).

Figures

FIGURES 224–232. Platymamersopsis voanjo sp. nov., female holotype (MD 78a): 224, idiosoma, ventral view; 225, idiosoma, dorsal view; 226, leg-I-2 to -6; 227, leg-II; 228, leg-III-2 to-6; 229, leg-IV-2 to -6; 230, capitulum with chelicera, lateral view; 231, left palp, lateral view; 232, right palp, ventro-medial view. Scale bars = 100 µm.

FIGURES 233–238. Platymamersopsis vietsi Cook, 1966, female paratype (SMF 4061): 233, leg-IV-5/ -6. Platymamersopsis chutteri K.O. Viets, 1981, male holotype (SMF 6857): 234, leg-IV-5/ -6. Platymamersopsis agnewi K.O. Viets, 1981, female holotype (SMF 6872): 235, leg-IV-5/ -6. Platymamersopsis nordenskioeldi K. Viets, 1914, holotype (SMF 1279): 236, leg-II-5/ -6; 237, leg-IV-5/ -6. Platymamersopsis similis Cook, 1966, male paratype (SMF 4051): 238, leg- IV-5/ -6.