Pseudosinella stewartpecki Katz, Soto-Adames & Taylor

Katz, Aron D., Taylor, Steven J., Soto-Adames, Felipe N., Addison, Aaron, Hoese, Geoffrey B., Sutton, Michael R. & Toulkeridis, Theofilos, 2016, New records and new species of springtails (Collembola: Entomobryidae, Paronellidae) from lava tubes of the Galapagos Islands (Ecuador), Subterranean Biology 17, pp. 77-120 : 90-94

Taxon classification Animalia Collembola Entomobryidae

Pseudosinella stewartpecki Katz, Soto-Adames & Taylor sp. n. Figs 14, 15, 16, 17

Etymology.

A patronym honoring Stewart B. Peck (Carleton University, Ottawa) whose work in caves and other habitats has done much to increase our understand ing of invertebrate biodiversity in the Galápagos Islands and throughout the Western Hemisphere.

Type material.

Holotype, ♂ on slide, Ecuador, Galápagos, Santa Cruz Island: La Llegada, leaf litter from entrance, 12.iii.2014 (C. Plowman, D. Butler and G. Hoese), GLP-095, INHS Acc. 567,414.

Paratypes, Ecuador, Galápagos, Santa Cruz Island: 2♂ on slides, La Llegada, leaf litter from entrance, 12.iii.2014 (C. Plowman, D. Butler and G. Hoese), GLP-095, INHS Acc. 567,415 & 467,416; 2♀ on slides, La Llegada, leaf litter from entrance, 12.iii.2014 (C. Plowman, D. Butler and G. Hoese), GLP-095, INHS Acc. 567,417 & 467,418; 2 on slides, La Llegada, leaf litter from entrance, 12.iii.2014 (C. Plowman, D. Butler and G. Hoese), GLP-095, INHS Acc. 567,419 & 467,420; 1 on slide, La Llegada, leaf litter from entrance, 12.iii.2014 (C. Plowman, D. Butler and G. Hoese), GLP-095, CDRS.

Description.

Body shape and color pattern. Maximum body length 1.14mm (♀) and 0.85mm (♂). Body with uniformly light blue pigment and white (rarely light orange) background (Fig. 14A, B).

Appendicular scales distribution. Scales present on head, body and ventral face of furcula. Antennae, legs, ventral tube and dorsal face of furcula without scales.

Head. Apical bulb of Ant. IV simple, membranous. Subapical sense organ acuminate; length subequal to guard sensillum. Sense organ of Ant. III with 2 normal rods; at least 3 additional short, blunt sensilla. Eyes 3+3. Dorsal head Mc (Fig. 14C) A0, A2a, A2 and A3 present, An series with 6+6 Mc (7+7 including An0). Pa5 absent. Prelabral setae weakly ciliate. Proximal labral setae ciliate, medial and distal labral setae smooth. Distal margin of labrum smooth. Outer maxillary lobe with basal and distal setae smooth and subequal. Sublobal plate with 3 appendages, subequal in length. Lateral appendage of labial papilla E reaching tip of papilla. Proximal labial setae smooth. Labial triangle setae formula: M1rEL1L2A1-3A4-5; A1-3 serrate, A4-5 smooth; r minute, smooth and conical; all other posterior setae ciliate (Fig. 14D). Postlabial setae ciliate; 4 setae and 4 scales along ventral groove; modified setae absent.

Body dorsal chaetotaxy. Th. II with Mc P3 present (Fig. 15A): polychaetosis absent; hood not developed. Th. III without Mc (Fig. 15B). Abd. I with 11 posterior mc, a6 present (Fig. 16A). Abd. II (Fig. 16B) with 2 Mc (m3, m5); all supplementary mc associated with bothriotricha acuminate and smooth; mc a2p, m4i, p5p, Lm, and Ll absent; seta a3 anterior to and reaching sensillum as. Abd. III (Fig. 16C) with 2 Mc (pm6, p6); all supplementary mc associated with bothriotricha acuminate and smooth; sensillum d2 and mc c3 and Ll absent; seta a3 anterior and reaching sensillum as; as less than half the length of m3; seta a7 anterior to im and em, reaching am6. Abd. IV (Fig. 17A) with 2 inner (B5, B6) and 7 lateral Mc (T6, D2-3, E2-4, F1); E1 a mc; 1 additional posterior-lateral Mc of uncertain homology present; supplementary mc associated with bothriotricha acuminate and smooth, mc s, a, and Pe absent; mc T3 anterior to and not reaching D1p; mc F2 in row with D2 and E2; posterior setae absent. Scales present on ventral face of furcula. Dens tubercle absent. Mucro with sub-apical tooth slightly longer than apical; basal spine smooth.

Legs. Trochanteral organ with 5 setae on all specimens when visible. Metatibiotarsi without outstanding posterior blunt setae. Tenent hair spatulate. Unguis with 3 inner teeth: 1 distal unpaired tooth and 2 basal paired teeth with 1 large tooth and 1 small tooth, the latter significantly smaller than distal unpaired tooth. Unguiculus lanceolate with at least 2 or more minute teeth on all legs (Fig. 17B).

Ventral tube. Anterior face with 4+4 or 5+5 ciliate setae; lateral flaps with 5+5 or 6+6 smooth setae; posterior face (Fig. 17C) with 2+2 smooth lateral setae, 1 smooth medial seta, and 1+1 minute conical microsensilla.

Remarks.

Pseudosinella stewartpecki sp. n. is the only member of the genus with 3+3 eyes, an apical antennal bulb, head series M and S without Mc, with 1 Mc on Th. II, and without Mc on Th. III. This new species is most similar to Pseudosinella intermixta , also described from the Galápagos Islands ( Folsom 1924). However, Pseudosinella stewartpecki sp. n. lacks head Mc in rows M and S, and the unpaired inner tooth of the unguis is smaller than the largest of the two inner paired teeth (Fig. 17B), whereas in Pseudosinella intermixta , head Mc M2 is present and the unpaired inner tooth is substantially larger than both paired teeth (Fig. 13B). Pseudosinella intermixta was collected on Baltra Island, which can be characterized as dry, lowland (maximum elevation of 100m) habitat. Pseudosinella stewartpecki sp. n. was collected in relatively moist, upland (251 m) habitat on Santa Cruz Island. These differences, in morphology and habitat, are sufficient for the separation Pseudosinella intermixta and Pseudosinella stewartpecki sp. n.

Distribution.

Santa Cruz Island, Galápagos, Ecuador.