Poecilaemula iching, Medrano & Kury & Martins & Proud, 2024

Medrano, Miguel, Kury, Adriano B., Martins, Pedro H. & Proud, Daniel N., 2024, The first harvestman described from Bocas del Toro Archipelago: a new Poecilaemula (Opiliones: Cosmetidae) and notes about the genus, Journal of Natural History 58 (9 - 12), pp. 311-329 : 317-325

Poecilaemula iching sp. n.

( Figures 6–10 )

Etymology. Species name is a noun in apposition, derived from I-Ching, an ancient Chinese divination text, because of the similarity between the transverse rod-shaped blots of this species and the hexagrams (figures composed of six stacked horizontal lines) of I-Ching.

Type data. Panamá, Bocas del Toro: ♂ Holotype and 1 ♂ 1 ♀ Paratypes ( UMFG 22601 ) from Panama, Bocas del Toro, Bocas del Toro, Isla Solarte 9.332°N, 82.218°W. 8–9 december 2014. A. Anker and P.H. Martins leg .; 1 ♀ Paratype ( MNRJ 9206 ), Isla Bastimentos , rainforest near the beach under logs, ‘hospital point’ 31.iii.2007 A. Anker leg. (Lost due to fire at the National Museum of the Federal University of Rio de Janeiro in 2018); 2 ♂ 1 ♀ Paratype ( MNRJ 369 ), Big Creek xi.2021, R. Quesada leg .; 3 ♂ 1 ♀ Paratype ( MNRJ 370 ), same data as previous ; 1 ♂ 1 ♀ Paratypes ( MZSP 78256 ), same data as previous.

Diagnosis. Poecilaemula iching differs from other members of Poecilaemula sensu stricto by having patella and tibia IV sexually dimorphic. Patella IV with two dorsal apophyses (retrolateral larger) and femur with retrodorsal and retroventral rows of acuminate tubercles in males. Ti IV remarkably tuberculated with a large dorsal row of large tubercles (present only distally in minor males). Areas of mesotergum the same colour as the rest of the scutum, not darker as in P. signata .

Description

Measurements. Major male: CL: 2.0, AL: 3.5, CW: 3.7, AW: 5.0, IOD: 1.1, Fe I: 4.7, Ti I: 2.9, Pa I: 1.3, Mt I: 4.7, Fe II: 9.8, Ti II: 7.5, Pa II: 1.6, Mt II: 10.5, Fe III: 6.9, Ti III: 3.8, Pa III: 1.9, Mt III: 6.8, Fe IV: 9.5, Ti IV: 5.2, Pa IV: 1.8, Mt IV: 9.9. Tarsal counts: 7-7/17-17/10-10/11-12.

Dorsum. Large-sized (dorsal scutum approx. 5 mm long) harvestman with long legs ( Figures 6 , 7 ). Dorsal scutum in dorsal view type β with attenuate constrictions ( Figure 8 ). Protoglyph and deutoglyph very shallow ( Figure 8 ). Dorsal scutum in lateral view almost flat, abdomen slightly convex, rising steadily from posterior and anterior borders to area III where it is the highest ( Figure 8c ). Shallow scutal groove separating carapace from abdominal scutum. No other grooves are visible on scutum, thus scutal areas only inferred from colouration pattern ( Figure 8 ). Areas I and III with two paramedian low tubercles, those of area I are more separated and lower than those of area III. Integument of dorsal scutum, free tergites and anal operculum smooth, except for the armature of areas I and III. Ocularium narrow and low, with gentle median depression ( Figure 8 ).

Chelicerae. ( Figures 6–8 ) Basichelicerite enlarged, cheliceral hand inflated, but without the dorsal incrassation that gives the kidney-shaped appearance of Andean cosmetids ( Rhaucus , Rhaucoides ). Posterior and ectal borders of bulla lined with strong tubercles. Fixed finger with one triangular tooth, movable finger with two triangular/ rounded teeth.

Pedipalps. ( Figure 8a,c ) Typical cosmetid pedipalps, with elongate trochanter, foliaceous femur; this is convex dorsally, with a dorsal keel formed by a row of few setiferous tubercles and a ventral row of 10 closely positioned setiferous tubercles. Ti depressed, slightly convex at the mesal and ectal sides, mesal side with a prominent keel, dorsally with some granules and ventrally smooth, with some spiniferous tubercles at the distal portion of both ectal and mesal sides. Tarsus cylindrical, with scattered dorsal setae and three well-marked ventral rows of subequal setae.

Legs. ( Figures 6 , 7 , 9 ) Legs becoming steadily thicker from leg II to IV. Coxa I–IV with some minute granules, coxae IV without clavi inguines and with one prolateral apical apophysis. Legs I–III unarmed. All femora straight. Patella IV with a dorsal row of tubercles, the distalmost larger than the others, and ventrally with two rows of small tubercles. Tibia IV with two rows of tubercles (smaller basally), the prolateral row with larger tubercles than those in the retrolateral row. Dorsal surface of Ti IV with one row of tubercles more than twice the size of those on the ventral surface. Mt IV with two rows of four to five small granules. Tarsi I–II with one smooth claw; tarsi III– IV with two subparallel smooth claws and tarsal process. Tarsal formula: 7(3)/17(3)/ 10/11-12.

Colour. ( Figures 6 , 7 ) Background of ventral and dorsal body and coxae I–IV: Strong Reddish Brown (40). Trochanters I–IV: Strong Orange (50). Distal femur to metatarsus: Dark Reddish Brown (44). Blots over the armature of area III: Brilliant Yellow (83), other blots of the mask: Vivid Orange (48).

Male genitalia. ( Figure 10 ) VP of penis subrectangular with concave distal border; VP with two lateral, elongated, patches of microsetae, separated by a wide longitudinal space. VP with two pairs of apical MS C curved and laterally inserted; two pairs MS D, the distalmost (D1) large, and the other (D2) minute, inserted dorso-laterally on the middle third of VP; one pair of short MS A, inserted laterally near to D2; MS E and MS B frequently encountered on the ventral face and immersed in microsetae were not visible. Glans mostly smooth, with finger-like conical dorsal process, stylus with wattle (= caruncle) with profuse parallel rows of barbels, one at each side of the opening.

Variation. Minormale paratype UMFG 22601: CL: 1.8, Al: 2.8, CW: 2.9, AW: 3.6, IOD: 0.7, Fe I: 4.1, Ti I: 2.7, Pa I: 1.1, Mt I: 4.1, Fe II: 8.6, Ti II: 7.1, Pa II: 1.5, Mt II: 10.1, Fe III: 6.4, Ti III: 3.6, Pa III: 1.4, Mt III: 6.4, Fe IV: 8.8, Ti IV: 4.8, Pa IV: 1.5, Mt IV: 9.0. Minor males bear slightly larger chelicerae than females ( Figure 7a ) and patellae IV and tibiae IV with smaller tubercles than major males ( Figures 7a , 9i–k ).

Female paratypes (average of two individuals UMFG 22601 and MNRJ 9206): CL: 1.8, Al: 3.0., CW: 3.1, AW: 4.0, IOD: 0.7, Fe I: 4.0, Ti I: 2.5, Pa I: 1.0, Mt I: 4.2, Fe II: 8.4, Ti II: 6.3, Pa II: 1.4, Mt II: 9.0, Fe III: 6.2, Ti III: 3.4, Pa III: 1.6, Mt III: 5.9, Fe IV: 8.4, Ti IV: 4.5, Pa IV: 1.6, Mt IV: 8.1. Females with chelicerae not inflated ( Figure 8b ), with coda wider than those of males ( Figures 7b , 8f ), legs III and IV thinner than those of minor and major males, and patellae and tibiae IV unarmed ( Figures 7b , 9e–h ).

Habitat and biology. Secretion from the ozopores intense yellow in colour, ejected in the form of drops, not jets, that are picked up by leg I and waved in front of the animal (eg leg dabbing behaviour). Stridulation was observed in one fight event (Rosannette Quesada pers. comm.).

Figures

Figure 6. Poecilaemula iching sp. n., in vivo specimens: a–d. major form of male from Bocas del Toro, Panamá. Photos: Arthur Anker and Pedro Martins.

Figure 7. Poecilaemula iching sp. n., in vivo specimens: a. minor form of male; b. female, from Bocas del Toro, Panamá. Photos: Arthur Anker and Pedro Martins.

Figure 8. Poecilaemula iching sp. n.: a. body, dorsal view male holotype (UMFG 22601); b. basichelicerite of the female, same scale as (a) (paratype MNRJ 9206); c. same as (a), lateral view; d–f. schematic variations of mask pattern. Scale bars for a–c: 1 mm.

Figure 9. Poecilaemula iching sp. n.: a–d. left leg of (major form) male holotype (UMFG 22601); a. femur IV, ventral view; b. patella and tibia IV, ventral view; c. same, retrolateral view; d. same, dorsal view. e–h. Left leg of female (UMFG 22601); e. femur, ventral view; f. patella and tibia, ventral view; g. same, retrolateral view; h. same, dorsal view. i–k. Left patella and tibia of minor form of male (UMFG 22601); i. ventral view, j. retrolateral view; k. dorsal view. Scale bars: 1 mm.

Figure 10. Poecilaemula iching sp. n., distal portion of the penis, holotype UFMG 22601: a. dorsal view; b. lateral view; c. ventral view. Scale bars: 100 µm.