Michaelia neotropica, Hernandes & Mironov & Bauchan & Ochoa, 2016

Hernandes, F. A., Mironov, S. V., Bauchan, G. R. & Ochoa, R. A., 2016, A new asymmetrical feather mite of the genus Michaelia Trouessart, 1884 (Astigmata: Freyanidae) from the Neotropical Cormorant, Phalacrocorax brasilianus (Pelecaniformes), Acarologia 56 (1), pp. 45-61 : 47-59

Michaelia neotropica n. sp. Hernandes and Mironov

( Figs. 1 – 10 )

Type material — Heteromorphic male holotype (DZUNESP-RC #3213), 4 heteromorphic males, 12 homeomorphic males and 62 female paratypes from Phalacrocorax brasilianus (Gmelin, 1789) ( Pelecaniformes : Phalacrocoracidae ), BRAZIL, Sªo Paulo State, Pedreira, 25 August 2008, D.V. Boas-Filho col. (#390); other paratypes: 2 heteromorphic males, 12 homeomorphic males and 7 females, same host species, BRAZIL, Sªo Paulo State, Artur Nogueira, 06 July 2010 (#744).

Depositories — Holotype heteromorphic male, 3 heteromorphs, 9 homeomorphs and 40 female paratypes at DZUNESP-RC; 1 heteromorph, 3 homeomorphs and 5 female paratypes at ZISP; 1 heteromorph, 2 homeomorphs and 5 female paratypes at USNM.

Description — Heteromorphic male (holotype, range for 4 paratypes in parentheses) — Idiosoma length from anterior end of prodorsal shield to lobar apices 1014 (1026 – 1062), widest part at level of humeral shield 421 (421 – 475). Prodorsal shield: occupying median part of prodorsum, margins poorly distinct, central part anterior to scapular setae with reticulate ornamentation. Setae vi, ve filiform, minute; setae si filiform, about 10 long, separated by 61 (57 – 65); setae se separated by 110 (107 – 114). Setae c2 filiform, situated on humeral shields. Subhumeral setae c3 filiform, 95 (75 – 105) long, situated ventrally on humeral shield. Hysteronotal shield: greatest length from anterior margins to lobar apices 748 (758 – 797), anterior margin rounded, poorly distinct, surface with reticulate pattern. Most dorsal setae filiform, except h1. Supranal concavity indistinct. Opisthosomal lobes strongly expressed, asymmetrical; length of terminal cleft from anterior angular end to tip of the longer lobe 259 (269 – 275). Lateral margins of terminal cleft with acute and slightly curved angular extensions at base and with blunt-angular extensions at midlevel; incision between basal and midlevel extension on each lobe slit-like, with margins almost touching. The lobe on the same side as longer leg II with slightly curved and shorter lobar tip. Setae h1 lanceolate, situated at level of bluntangular extensions of opisthosomal lobes, 52 (45 – 52) long in the longest lobe and 61 (44 – 57) long on opposite side. Distances between dorsal setae: c1:c1 202 (192 – 219), c1:d1 150 (153 – 178), d1:d1 97 (101 – 112), d1:e1 217 (221 – 278), e1:e1 169 (156 – 163), ps1:ps1 132 (127 – 153), h1:h1 111 (108 – 120), h3:h3 169 (146 – 189), h2:h2 199 (194 – 217).

Pseudorutellar processes directed laterally, elongated and narrowing towards the tip; two small medial spines between processes; distal half of these processes with texture of many small regularly spaced papillae resembling gecko skin or shagreen leather ( Fig. 10E ). Sternum and inner tips of all or almost all epimerites fused forming entire coxo-sternal network with closed coxal fields I – IV. Genital apparatus 43 (49 – 52) in length, 30 (30 – 36) in width, situated far posterior to level of trochanters IV and completely encircled by adanal shield ( Fig. 9E ). Anal suckers 39 (35 – 39) in diameter, distance between centers of suckers 73 (74 – 84), corolla with three distinct dark inflations.

Anterior legs I, II asymmetrical, most noticeable in legs II. Femur I co-lateral to longer leg II bear- ing a strong apico-ventral spine ( Fig. 10D ); only small rounded protuberance present in corresponding part of femur I of opposing side ( Fig. 2D ). Both genua I with ventral longitudinal crest. Tarsus of larger leg II slightly bent and with distal margin broadened and flattened. Legs III, IV symmetrical, without crests or processes. Seta d of tarsus IV spine-like, only alveolus of seta e present. Length of two anterior pairs of legs from femur to tarsal tip (smaller/longer): I 249 (241 – 271), I 246 (265 – 283), II 329 (359 – 387), II 467 (482 – 514).

Homeomorphic male (range for 6 paratypes in parentheses) — Idiosoma length from anterior end of prodorsal shield to lobar apices 890 – 951, widest part at level of humeral shields 385 – 408. Prodorsal shield: as in heteromorphic male. Setae vi, ve filiform, minute; si filiform, about 10 long, separated by 57 – 61; setae se separated by 96 – 105. Setae c2 filiform, situated on humeral shields. Subhumeral setae c3 filiform, 75 – 85, situated ventrally on humeral shield. Hysteronotal shield: greatest length from anterior margins to lobar apices 652 – 696, anterior margin shaped as a trapezium [although this shape is poorly detectable in some specimens], surface as in the heteromorphic male. Most dorsal setae filiform, except h1. Supranal concavity indistinct. Opisthosomal lobes strongly expressed, symmetrical or almost symmetrical; inner margins of lobes almost straight; terminal cleft from anterior margin to lobar tip 207 – 234; anterior margin of cleft with pair of small acute extensions; incisions at bases of lobes small, triangular. Setae h1 lanceolate, 60 – 77 long. Distances between dorsal setae: c1:c1 163 – 186, c1:d1 120 – 135, d1:d1 80 – 109, d1:e1 192 – 227, e1:e1 111 – 138, ps1:ps1 79 – 134, h1:h1 114 – 134, h3:h3 116 – 175, h2:h2 184 – 227.

Pseudorutellar processes as in heteromorph. Sternum and inner tips of epimerites II fused, enclosing coxal fields I; coxal fields II open; coxal fields III, IV closed as in heteromorphs. Genital apparatus 38 – 50 in length, 31 – 35 in width, situated slightly posterior to level of trochanters IV, completely surrounded by adanal shield. Anal suckers 35 – 38 in diameter, distance between centers of suckers 73 – 81, corolla with three distinct dark inflations.

Anterior legs I, II asymmetrical. Femur and genu of larger (thicker) leg I with large ventral longitudinal crests ( Fig. 4B ); these crests absent on equivalent segments of the smaller leg I. Tarsus of thicker leg I broadened basally and with retrograde dorsolateral spine; tarsus of thinner leg II with rounded ventral tubercle. Legs II and posterior legs III, IV as in heteromorph. Length of anterior legs from femur to tarsal tip (the smaller leg is given first): I 246 – 250, I 250 – 273, II 329 – 346, II 420 – 458.

Female (range for 6 paratypes in parentheses) — Idiosoma length from anterior end of prodorsal shield to lobar apices 721 – 794, width at level of humeral shields 411 – 447. Prodorsal shield: covering almost all prodorsum, borders indistinct, anterior part with 8-9 pairs of transverse, gill-like striae (somewhat resembling Venetian blinds), central part with reticulate pattern. Setae vi, ve filiform, minute; setae si filiform, about 10 long, separated by 58 – 63; setae se separated by 103 – 110. Setae c2 filiform, situated on humeral shields. Subhumeral setae c3 filiform, situated ventrally on humeral shield. Hysteronotal shield: covering almost all hysterosoma, greatest length from anterior margins to lobar apices 503 – 558, anterior margin rounded, poorly distinct, surface with reticulate pattern. Most dorsal setae filiform, except ps1, f2 lanceolate; ps1 82 – 94, f2 126 – 140 long; h2 472 – 609 long, h3 493 – 603 long. Supranal concavity indistinct. Opisthosomal lobes moderately expressed; terminal cleft from anterior end to lobar tips 28 – 42. Copulatory opening terminal, situated on small tubercle on terminal cleft margin. Setae ps1 lanceolate, slightly curved. Distances between dorsal setae: c1:c1 139 – 167, c1:d1 105 – 119, d1:d1 114 – 135, d1:e1 158 – 173, e1:e1 165 – 185, ps1:ps1 159 – 173, h3:h3 212 – 224, h2:h2 258 – 271, f2:f2 294 – 323.

Pseudorutellar processes as in males. Basal part of epimerites I, II, IIa with heavily sclerotized inflations, connected to each other with wide sclerotized bridges. Coxal fields III closed. Oviporus at midlevel between trochanters III and IV. Sclerotized epigynum absent.

All legs symmetrical, without any crests or processes. Setae d of tarsi setiform. Length of two anterior pairs of legs from femur to tarsal tip: I 229 – 243, II 227 – 244.

Differential diagnosis — The new species, Michaelia neotropica Hernandes and Mironov n. sp., is close to M. urile ( Dubinin, 1953) by the absence of a retrograde spur on both tarsi I and a ventral spine on the femur of the smaller leg I in heteromorphic males. A spur on tarsus I is present in heteromorphic males of M. amplosinus ( Gaud, 1970) and M. heteropus , and a ventral spine on femur I is present in M. heteropus and M. microcarbonis ( Dubinin, 1953) . Heteromorphic males of Michaelia neotropica differ from those of M. urile by having a narrower incision on opisthosomal lobes anterior to setae h1 with its margins almost touching each other, and by the relatively longer legs I with their ambulacrum reaching the midlevel of tarsus of the elongated leg II. In heteromorphic males of M. urile , the lobar incisions anterior to setae h1 are wide, rounded, about half as wide as long, and the ambulacra of tarsi I reach only the level of solenidion φ on tibia of enlarged leg II. Considering the closest species in relation to the new one being described ( Michaelia urile vs M. neotropica n. sp.), differences between homeomorphic males are minimal, as far as it is detectable from the original descriptions. As far as we know, females are very hardly distinguishable between all species, and we prefer to avoid mentioning preliminary differences at this point.

Etymology — The specific epithet refers to the common name of the host, the Neotropical Cormorant.

Figures

FIGURE 1: Michaelia neotropica n. sp., heteromorphic male: A – dorsal view, B – ventral view.

FIGURE 2: Michaelia neotropica n. sp., heteromorphic male legs: left leg I dorsal (A) and ventral (B), right leg I dorsal (C) and ventral (D), right leg II dorsal (E) and ventral (F), left leg II dorsal (G) and ventral (H), leg III dorsal (I), tibia and tarsus III ventral (J), leg IV dorsal (K), tibia and tarsus IV ventral (L).

FIGURE 3: Michaelia neotropica n. sp., homeomorphic male: A – dorsal view, B – ventral view.

FIGURE 4: Michaelia neotropica n. sp., homeomorphic male legs: left leg I dorsal (A) and ventral (B), right leg I dorsal (C) and ventral (D), left leg II dorsal (E) and ventral (F), right leg II dorsal (G) and ventral (H), leg III dorsal (I), genu, tibia and tarsus of leg IV dorsal (J).

FIGURE 5: Michaelia neotropica n. sp., female: A – dorsal view, B – ventral view.

FIGURE 6: Michaelia neotropica n. sp., female legs: leg I dorsal (A); genu, tibia and tarsus of leg I, ventral (B); leg II dorsal (C); genu, tibia and tarsus of leg II, ventral (D); leg III dorsal (E) and ventral (F); leg IV dorsal (G) and ventral (H).

FIGURE 7: Michaelia neotropica n. sp., Low Temperature Scanning Microscope (LTSEM) pictures of heteromorphic male (A), homeomorphic male (B), and female (A), dorsal view.

FIGURE 8: Michaelia neotropica n. sp., LTSEM pictures: prodorsal shield of homeomorphic male (A) and female (B), detail of female prodorsal shield (C); dorsal view of opisthosomal region of heteromorphic (D) and homeomorphic (E) males.

FIGURE 9: Michaelia neotropica n. sp., LTSEM pictures: ventral view of heteromorphic male (A), ventral views of gnathosoma of heteromorphic male (B) and female (C); external genitalia (E) and detail of palptarsus of heteromorphic male (D).

FIGURE 10: Michaelia neotropica n. sp., LTSEM pictures: ventral view of left tarsus II of heteromorphic male (A), dorsal view of left leg I of homeomorphic male (B), dorsal view of legs III and IV of heteromorphic male (C), ventral view of gnathosoma, femur and genu I of heteromorphic male (D), detailed view of pseudorutellar process (E), ventral view of ambulacrum II of heteromorphic male (F), lateral view of female in the feather corridor (G).