New records and new species of springtails (Collembola: Entomobryidae, Paronellidae) from lava tubes of the Galapagos Islands (Ecuador) Katz, Aron D. Taylor, Steven J. Soto-Adames, Felipe N. Addison, Aaron Hoese, Geoffrey B. Sutton, Michael R. Toulkeridis, Theofilos Subterranean Biology 2016 17 77 120 http://zoobank.org/93AB0B74-D429-4E08-A33E-B4D8E922E222 Katz, Soto-Adames & Taylor Collembola Entomobryidae Pseudosinella CoL Animalia Pseudosinella vulcana Collembola 17 94 Arthropoda species vulcana  Etymology. Latin, feminine form, alludes to the shield volcanoes of the GalapagosIslands.  Type material. Holotype, ♂ on slide, Ecuador, Galapagos, Santa Cruz Island: Cueva Chato 2, leaf litter at entrance, 15.iii.2014 (S. Taylor, J. Jacoby, S. Hagan and R. Toomey), GLP-086, INHS Acc. 567,411. Paratypes, Ecuador, Galapagos, Santa Cruz Island: 1♀ on slide, Cueva Chato 2, leaf litter at entrance, 15.iii.2014 (S. Taylor, J. Jacoby, S. Hagan and R Toomey), GLP-086, INHS Acc. 567,412; 1♀ on slide, Cueva Chato 2, drip pool, dark zone, 15.iii.2014 (S. Taylor, J. Jacoby, S. Hagan and R. Toomey), GLP-090, INHS Acc. 567,413; 1♀ on slide, Cueva Chato 2, drip pool, dark zone, 15.iii.2014 (S. Taylor, J. Jacoby, S. Hagan and R. Toomey), GLP-090, CDRS.  Description. Body shape and color pattern. Maximum body length 0.74mm (♀) and 0.68mm (♂). Body white, without pigment, except for minute black eye spot (Fig. 18A).  Figure 18. Pseudosinella vulcanasp. n. A habitus (INHS Acc. 567,412) with detail of eyespot (arrow) on another specimen B labial triangle C dorsal chaetotaxy of head. Appendicular scales distribution. Scales limited to head, body and ventral face of furcula. Antennae, legs, ventral tube and dorsal face of furcula without scales. Head. Apical bulb of Ant. IV absent; subapical sense organ clubbed, as large as guard sensillum; additional bulb-like sense organ present within a deep pit. Sense organ of Ant. III with 2 normal rods; at least 2 additional short, blunt sensilla present. Eyes 1+1, each within a minute eye spot. Dorsal head chaetotaxy (Fig. 18B) with 5+5 Mc in An series, in addition to Mc A0, A2, A3, and Pa5. Prelabral setae acuminate and 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 seta-like appendages, middle appendage 2' longer and 2' thicker than outer appendage. Lateral appendage of labial papilla E S-shaped, not reaching tip of papilla. Proximal labial setae smooth. Labial triangle setae formula: M1rEL1L2A1-5; A1-5 smooth; r minute, smooth, and conical; all other posterior setae ciliate (Fig. 18C). Postlabial setae ciliate; 3 setae and 4 scales along each side of ventral groove; modified setae absent. Dorsal body chaetotaxy. Th. II without Mc (Fig. 19A): polychaetosis absent; mesothoracic hood not developed. Th. III without Mc (Fig. 19B). Abd. I (Fig. 19C) with 9 posterior mc; seta a6 absent. Abd. II (Fig. 19D) with 3 Mc (m3, m5, a2); Mc a2 short, thickened distally, with relatively small socket; supplementary setae mi, Li, Ll and m4i associated with bothriotricha m2 and a5 ciliate and weakly fan-shaped/truncate; all other mc acuminate and smooth; mc a2p and Lm, absent; seta a3 external to and half the length of as. Abd. III (Fig. 20A) with 2 Mc (pm6, p6); supplementary mc mi, ml, a2, Li, Lm, im and a6 weakly fan-shaped and ciliate, all other mc smooth; sensillum d2 and mc c3 and Ll absent; seta a3 anterior to and nearly reaching sensillum as; as twice as long as m3; seta a7 posterior to im and em and external to am6. Abd. IV (Fig. 20B) with 2 inner (B5, C1) and 4 lateral Mc (D3, E2, E3, F1); at least 1 additional posterior-lateral Mc of uncertain homology present; supplementary mc associated with bothriotricha weakly fan-shaped and ciliate; seta s present; mc T3 anterior to and not reaching D1p; posterior setae absent.  Figure 19. Pseudosinella vulcanasp. n. A-Ddorsal chaetotaxy: A Th. II B Th. III C Abd. I D Abd. II.  Figure 20. Pseudosinella vulcanasp. n. A-Bdorsal chaetotaxy: A Abd. III B Abd. IV C prothoracic claw complex D posterior face of collophore.  Legs. Trochanteral organ with up to 9 setae. Metatibiotarsi with 2 outstanding posterior blunt seta. Tenent hair short and acuminate. Unguis with 4 inner teeth; 1 large wing-like inner tooth with 2 basal minute paired lateral teeth, and 1 unpaired proximal tooth. Unguiculus basally swollen on all legs; with 1 large outer wing tooth (Fig. 20C). Ventral tube. Lateral flaps with 4+4 or 5+5 smooth setae, anterior face with 4+4 ciliate setae, and posterior face (Fig. 20D) with 1+1 smooth setae and 1+1 minute conic microsensilla. Furcula. Dens tubercle absent. Mucro with sub-apical tooth larger than apical tooth; basal spine smooth.  Remarks.  Pseudosinella vulcanasp. n. is the only member of the genus with 1+1 eyes and with a wing tooth on both the unguis and unguiculus. This new species is most similar to Pseudosinella biunguiculataEllis, 1967, sensu Mari Mutt (1986), but differs by having1+1 eyes, Abd. IV supplemental seta s present (Fig. 20B), and only 1+1 paired setae on the posterior face of the collophore (Fig. 20D), where as in Pseudosinella biunguiculataeyes and supplemental seta s are absent and the posterior face of the collophore has 2+2 paired setae and 1 unpaired medial seta.   Pseudosinellavulcanasp. n. has 2 thickened, apically blunt metatibiotarsal setae, which was originally thought to differ from Pseudosinella biunguiculatasince Mari Mutt (1986)described only 1 blunt metatibiotarsal seta. However, we observed 2 metatibiotarsal setae on Pseudosinella biunguiculatafrom Puerto Rico (Guajataca Commonwealth Forest, at end of trail #10, leaf litter, 19.v.2009, F. Soto, coll.). Pseudosinella caoiChen, Wang & Christiansen, 2002 and Pseudosinella fujiokaiYosii, 1964, sensu Christiansen and Bellinger (1992), also have blunt metatibiotarsal setae, ungual wing teeth, Head Mc A3 (R2), and lack Mc on Th. II and Th. III, but can be differentiated from Pseudosinella vulcanasp. n. by characters outlined in Table 2.  Table 2. Diagnostic characters of Pseudosinella vulcanasp. n. in relation to Pseudosinella biunguiculata(4 morphological forms from Puerto Rico with locations(s) indicated in parentheses, and the holotype), Pseudosinella fujiokai, and Pseudosinella caoi. Present (+), absent (-), not reported (?).    Species/forms Eyes Labial triangle seta r Number of blunt setae on metatibiotarsi Hd A2 (R1) Hd A3 (R2) Hd Pa5 (Po) Abd. 2 m4 Abd. 2 m4i Abd. 4 suppl. seta s Tenent hair Unpaired ungual tooth   Pseudosinella vulcana   Pseudosinella biunguiculata   Pseudosinella biunguiculata   Pseudosinella biunguiculata   Pseudosinella biunguiculata   Pseudosinella biunguiculata   Pseudosinella fujiokai   Pseudosinella caoi Chen et al., 2002  Mari Mutt (1986)described 3 morphologically distinct forms among and within populations of Pseudosinella biunguiculatain Puerto Rico that differ in dorsal chaetotaxy (presence/absence of head Mc A3 (R2)) and tenent hair morphology (clavate/acuminate). He also noted differences between the Puerto Rican forms and  Ellis'(1967)type specimens; primarily the absence of head Mc A2 (R1), A3 (R2), and Pa5 (Po) on the holotype. Furthermore, the original description of Pseudosinella biunguiculatadoes not show the presence of m4i on Abd. II, which is distinctly present in the Puerto Rico populations. The high levels of morphological variation exhibited among these forms suggest that Pseudosinella biunguiculatarepresents a species complex: small and seemingly insignificant differences in morphology have been shown to correlate with large genetic distances among populations, indicating the presence of species complexes ( Porco et al. 2012, Cicconardi et al. 2013, Katz et al. 2015a). In fact, Soto-Adames (2002b)observed large genetic differences between sympatric individuals of Puerto Rican Pseudosinella biunguiculata, but these differences could not be correlated with differences in morphology due to destructive DNA extraction methods. Additional investigations utilizing morphological and molecular data may clarify species-level relationships among populations of Pseudosinella biunguiculata, a species with a widespread neotropical distribution. See Table 2 for a list of diagnostic characters separating the different forms and descriptions of Pseudosinella biunguiculata.  Pseudosinella vulcanasp. n. was collected from entrance and from the surface of a drip pool (Fig. 2A) within the dark zone, in generally cool, moist, low light conditions (Table 3), suggesting the species may be a troglophile.  Table 3. Environmental conditions associated with March 2014 collections of Entomobryoideafrom lava tube sites on Santa Cruz and Isabela islands, GalapagosIslands, Ecuador.    Species Light (Lux) Relative humidity (%) Air temperature (°C) Soil temperature (°C) Elevation (m) Cave zone   Heteromurus (Heteromurtrella) nitens   Lepidocyrtus nigrosetosus   Pseudosinella stewartpecki   Pseudosinella vulcana   Coecobrya   Entomobrya darwini   Cyphoderus cf. agnotus   Salina  Distribution. Santa Cruz Island, Galapagos, Ecuador.