Research Article |
Corresponding author: James Starrett ( jstarrett@mail.sdsu.edu ) Academic editor: Gonzalo Giribet
© 2016 James Starrett, Shahan Derkarabetian, Casey H. Richart, Allan Cabrero, Marshal Hedin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Starrett J, Derkarabetian S, Richart CH, Cabrero A, Hedin M (2016) A new monster from southwest Oregon forests: Cryptomaster behemoth sp. n. (Opiliones, Laniatores, Travunioidea). ZooKeys 555: 11-35. https://doi.org/10.3897/zookeys.555.6274
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The monotypic genus Cryptomaster Briggs, 1969 was described based on individuals from a single locality in southwestern Oregon. The described species C. leviathan Briggs, 1969 was named for its large body size compared to most travunioid Laniatores. However, as the generic name suggests, Cryptomaster are notoriously difficult to find, and few subsequent collections have been recorded for this genus. Here, we increase sampling of Cryptomaster to 15 localities, extending their known range from the Coast Range northeast to the western Cascade Mountains of southern Oregon. Phylogenetic analyses of mitochondrial and nuclear DNA sequence data reveal deep phylogenetic breaks consistent with independently evolving lineages. We use discovery and validation species delimitation approaches to generate and test species hypotheses, including a coalescent species delimitation method to test multi-species hypotheses. For delimited species, we use light microscopy and SEM to discover diagnostic morphological characters. Although Cryptomaster has a small geographic distribution, this taxon is consistent with other short-range endemics in having deep phylogenetic breaks indicative of species level divergences. Herein we describe Cryptomaster behemoth sp. n., and provide morphological diagnostic characters for identifying C. leviathan and C. behemoth.
Short-Range Endemic, DNA barcoding, cryptic species, Bayes Factor Delimitation, genealogical congruence
With more than 4100 described species (
In this study we increase the number of Cryptomaster localities to 15, all from mountainous southwestern Oregon. We use multi-locus DNA sequence data to investigate population structure and divergence from samples throughout this range. We recover a deep and concordant phylogenetic split for five loci that is indicative of species level divergence. Discovery and validation species delimitation approaches are used to assess support for multiple species within Cryptomaster. Also, we examine morphological differentiation between the divergent genetic groups to provide diagnostic characters for species identification. We delimit two species within Cryptomaster, and here describe Cryptomaster behemoth sp. n. This research highlights the importance of short-range endemic arachnids for understanding biodiversity (
We collected 77 Cryptomaster individuals from 14 localities in the Coast and Cascade Mountains of southern Oregon (Fig.
Distribution of Cryptomaster leviathan (closed circles) and C. behemoth (open circles) in southwestern Oregon. Small X’s represent locations in a potential Cascade to Coast corridor where we have collected other travunioids, but not Cryptomaster. Inset: male C. leviathan from the Sixes River location.
Genomic DNA was extracted from multiple legs per specimen using the DNeasy Blood and Tissue Kit (Qiagen, Valencia, CA) and the manufacturer’s protocol. Sequence data were obtained for the mitochondrial gene cytochrome c oxidase subunit I (COI), and four nuclear loci (Toll, putative; F-box/LRR-repeat protein, putative; Protein phosphatase 2A regulatory subunit A, putative; Neuromusculin, putative). DNA amplification was performed in a total volume of 25 µL with 1.6 units Platinum Taq (Invitrogen, Carlsbad, CA), 2.2 mM MgCl2, 1X PCR buffer, 0.2 mM each dNTP, and 0.4 µM of each primer (Suppl. material
Phylogenetic and genetic distance based discovery analyses were used to generate species hypotheses. Maximum likelihood (ML) analyses of individual loci were conducted with RAxML BlackBox v.8.1.11 (
Based on the results of gene tree and species discovery approaches, we compared four alternative species hypotheses using Bayes Factor Delimitation (
Results of Bayes Factor Delimitation analysis. Species hypotheses are indicated in Fig.
MLE (PS) | BF | MLE (SS) | BF | |
---|---|---|---|---|
4 Species | -4939.87 | 12.14 | -4942.67 | 13.03 |
3 Species | -4940.62 | 13.63 | -4943.17 | 14.03 |
2 Species | -4933.80 | - | -4936.16 | - |
1 Species | -5010.68 | 153.75 | -5014.01 | 155.70 |
Linear measurements were taken as in
Genetic sampling results, GenBank accession numbers, and genetic diversity statistics are summarized in Suppl. material
Maximum likelihood COI gene tree with vertical bars showing results of discovery and validation analyses. Blue text = C. leviathan, red text = C. behemoth. Numbers adjacent to nodes indicate bootstrap support greater than 70%. The tree was rooted with Speleomaster lexi (not shown, see Suppl. material
A–D Maximum likelihood nuclear gene trees; numbers adjacent to nodes indicate bootstrap support greater than 70%. Trees were rooted with Speleomaster lexi (not shown, see Suppl. material
ABGD analysis of the COI data supported a four species hypothesis (Fig.
Multiple species hypothesis models were tested using Bayes Factor Delimitation (Fig.
We note that within each species of Cryptomaster two forms are present, a larger and a smaller form, that show a bimodal size distribution (Fig.
Cryptomaster dorsal coloration. A Male C. leviathan (SDSU_OP4039) B Holotype male C. behemoth (CASENT9039221, SDSU_OP4026) C Female C. leviathan (SDSU_OP4037) D Allotype female C. behemoth (CASENT9039221, SDSU_OP4029). Scale bars: 1 mm.
Cryptomaster diagnostic morphological characters. A–B Lateral view of seta-bearing tubercle found on ventral side of palpal trochanter A C. leviathan, Judge Hamilton B C. behemoth, Brice Creek C–D Lateral view of male penis (“D” indicates dorsal side) C C. leviathan, Laverne County Park. D C. behemoth, Oakridge E–F Close-up lateral view of penis tip showing spines on dorsal plate E C. leviathan, Laverne County Park, detail showing erect apical spines F C. behemoth, Oakridge, detail showing appressed apical spines. Scale bar: 200 µm (A, B); 300 µm (C–D); 40 µm (E–F).
Morphological abbreviations: DCS = distal cheliceral segment , GO = genital operculum , LII = leg II , OC = ocularium , PCS = proximal cheliceral segment , PF = pedipalpal femur , PT = pedipalpal trochanter , SBT = seta-bearing tubercle . All measurements are in millimeters. Morphological images have been submitted to Morphbank.
Cryptomaster leviathan Briggs, 1969: 41–43, figures 15–25.
Holotype male and five female paratypes from 4.5 miles south of Gold Beach, Curry County, Oregon, 29 January 1967, under spruce bark in virgin spruce forest, coll. T. Briggs, V. Lee, and K. Hom.
This species differs from C. behemoth in having the enlarged SBT of PT acute (Fig.
SDSU_TAC000021, Morphbank Specimen ID: 855927
<http://www.morphbank.net/?id=855927>, 14 SEM images
SDSU_TAC000022, Morphbank Specimen ID: 855928
<http://www.morphbank.net/?id=855928>, 7 SEM images
SDSU_TAC000027, Morphbank Specimen ID: 855931
<http://www.morphbank.net/?id=855931>, 17 SEM images
SDSU_TAC000204, Morphbank Specimen ID: 855933
<http://www.morphbank.net/?id=855933>, 19 SEM images
SDSU_TAC000248, Morphbank Specimen ID: 856245
<http://www.morphbank.net/?id=856245>, 4 SEM images
MALE: Measurements of holotype male, with the average and range of all three specimens measured in parentheses (Suppl. material
Body length 3.44, scute length 2.75 (2.71; 2.5–2.89), scute width 3.06 (2.75; 2.5–3.06), prosoma width 2.05 (1.95; 1.81–2.05). Shoulder tubercles present but small. Scute microgranulate. Holotype discolored due to preservation; for other specimens, integument color contrasts dorsally at midline between prosoma and opisthosoma, although not as strongly as in females. OC width 0.59 (0.55; 0.49–0.59). Ventral surface microgranulate. GO missing in holotype, length 0.3–0.34, width 0.28–0.31.
PT with acute mesal SBT. PF length 2.01 (1.98; 1.8–2.13), PF depth 0.72 (0.69; 0.64–0.72), with 7 (sometimes 5–6) spines, with the basal pair prominent, 3 (sometimes 4) enlarged dorsal spines, and 2 enlarged prolateral spines distally. PCS with 3 anterior spines dorsally and with 2 or 3 small retrolateral spines; DCS with 2 rows of small, dorsal, forward-facing acute SBTs. PCS width 0.42, DCS length 1.6, DCS width 0.46.
Trochanter 0.57, femur 0.92, patella 0.7, tibia 1.48, metatarsus 1.72, tarsus 1.04. LII length 11.19 (11.31; 10.69–12.06): trochanter 0.62 (0.6; 0.58–0.62), femur 2.73 (2.73; 2.55–2.91), patella 0.94 (0.89; 0.77–0.95), tibia 2.3 (2.37; 2.28–2.55), metatarsus 2.49 (2.61; 2.49–2.8); tarsus 2.1 (2.11; 1.99–2.25); tibia distally and ventrally swollen, with 5 rounded SBTs, 1–3 with setae twisted. Tarsal count 5-[11–15]-5–6.
Penis elongate; glans laterally compressed, dorsal plate extending outward into a more angled and acute keel shaped protrusion, with two pairs of spines, apical pair erect (pointing along the longitudinal axis of the penis), subapical pair appressed to dorsal plate; ventral plate cultriform with dorsally curved apical process.
FEMALE: Nineteen total individuals examined, including five paratypes; average measurements taken for subset (Suppl. material
Scute length 2.82 (2.69–3.03), scute width 3.01 (2.84–3.13), prosoma width 1.96 (1.8–2.14). Relative to males very dark, with strong contrast at midline between light-brown prosoma and dark-brown opisthosoma. OC width 0.56 (0.51–0.6). GO length 0.37 (0.33–0.39), width 0.38 (0.34–0.4).
PT mesal SBT acute. PF length 1.84 (1.68–1.94), PF depth 0.63 (0.58–0.67), usually with 5 (up to 7) ventral spines, 4 dorsal spines (2 to 6), and 2 distal prolateral spines. PCS with 2–3 anterior spines dorsally, with 1–4 small retrolateral spines.
LII length 10.23 (9.61–10.81): trochanter 0.58 (0.54–0.67), femur 2.53 (2.35–2.63), patella 0.83 (0.76–0.89), tibia 2.16 (1.99–2.29), metatarsus 2.39 (2.16–2.55), tarsus 1.92 (1.81–2.0); tibia without distal ventral swelling.
Ovipositor with four lobes, lateral lobes largest with seven apical setae, and a single large spine with a bifurcate tip, ventral lobe smallest.
Cryptomaster habitus. A–B Habitus, dorsal A C. leviathan, Judge Hamilton B C. behemoth, Brice Creek C–D Habitus, lateral C C. leviathan, Judge Hamilton D C. behemoth, Oakridge (female) E–F Pedipalp, retrolateral E C. leviathan, Judge Hamilton F C. behemoth, Oakridge. Scale bar: 2 mm (A, B, C, D); 1 mm (E–F).
Cryptomaster appendages. A–B Proximal cheliceral segment, dorsal A C. leviathan, Reedsport B C. behemoth, Oakridge C–DSBT of palpal trochanter, lateral C C. leviathan, Laverne County Park D C. behemoth, Oakridge E–F Leg II tibia, distal swelling, retrolateral E C. leviathan, Judge Hamilton F C. behemoth, Oakridge. Scale bar: 500 µm (A, B); 100 µm (C, D); 400 µm (E, F).
Cryptomaster penises. A–B Apicolateral (“D” indicates dorsal side) A C. leviathan, Laverne County Park B C. behemoth, Brice Creek C–D Apicodorsal C C. leviathan, Judge Hamilton D C. behemoth, Oakridge E–F Apical E C. leviathan, Judge Hamilton F C. behemoth, Brice Creek. Scale bar: 100 µm (A, B, E, F); 200 µm (C, D).
Cryptomaster ovipositors. A–E C. leviathan, Reedsport A Apical (“DL” indicates dorsal lobe) B Lateral C Apical, emphasizing setae and spine arrangement D Lateral, emphasizing setae and spine arrangement E Apical, spine F C. behemoth, Oakridge, sagittal view, emphasizing setae and spine arrangement, 40×. Scale bar: 100 µm (A, B); 50 µm (C, D); 25 µm (E).
See Suppl. material
For specific localities, habitats, and microhabitats see Suppl. material
Cryptomaster
leviathan
[partim]
Cryptomaster
leviathan
[partim]
The specific epithet is a noun in apposition, which refers to the large size of this species. Like leviathan, the specific epithet behemoth is derived from Hebrew; these are the names of two large and powerful beasts mentioned in the Book of Job.
Holotype male and allotype female (deposited in CAS, CASENT9039221; SDSU_OP4026, SDSU_OP4029) from near Brice Creek, Brice Creek Road, 3.3 miles southeast of Forest Service Road 17, Umpqua National Forest, Lane County, Oregon; N43.6749°, W122.7290°; elevation 418 m; 29 March 2015; habitat: Acer macrophyllum, Thuja plicata, Pseudotsuga menziesii, Polystichum munitum forest; in and under large woody debris and other forest litter; collectors: J. Starrett, S. Derkarabetian, A. Cabrero, C. Richart. Paratypes: One female (deposited in CAS) from identical locality and information as holotype and allotype. Three females (two deposited in CAS, 1 deposited in SDSU_TAC; SDSU_TAC0000023) from Goodman Creek Road, off OR 58, northwest of Oakridge, Lane County, Oregon; N43.8429°, W122.6854°; elevation 340 m; 19 August 2014; habitat: old growth Douglas fir forest/woody debris; collectors: M Hedin, E Ciaccio, A Cabrero, J Starrett, S Derkarabetian. Two females (one each deposited in CAS and SDSU_TAC; SDSU_TAC0000234) from Brice Creek, Brice Creek Road, 3.3 miles southeast of FS 17, Umpqua National Forest, Lane County, Oregon; N43.6760°, W122.7290°; elevation 418 m; 29 March 2015; habitat: Acer macrophyllum, Thuja plicata, Pseudotsuga menziesii, Polystichum munitum forest; woody debris and litter; collectors: J Starrett, S Derkarabetian, A Cabrero, C Richart. One female (deposited in SDSU_TAC; SDSU_TAC0000028) from Highway 126, near Quartz Creek Road, Lane County, Oregon; N44.1248°, W122.3846°; elevation 300 m; 19 August 2014; habitat: decent Pseudotsuga menziesii forest; woody debris; collectors: M Hedin, E Ciaccio, A Cabrero, J Starrett, S Derkarabetian.
This species differs from C. leviathan by having the enlarged SBT of PT rounded (Fig.
CASENT9039221, Holotype, Morphbank Specimen ID: 855951
<http://www.morphbank.net/?id=855951>, 1 image
CASENT9039221, Paratype, Morphbank Specimen ID 855929,
<http://www.morphbank.net/?id=855929>, 1 image
SDSU_TAC000023.5, Morphbank Specimen ID: 855929
<http://www.morphbank.net/?id=855929>, 1 SEM image
SDSU_TAC000023.6, Morphbank Specimen ID: 855930
<http://www.morphbank.net/?id=855930>, 12 SEM images
SDSU_TAC000203, Morphbank Specimen ID: 855932
<http://www.morphbank.net/?id=855932>, 16 SEM images
SDSU_OP1641, GUID: 38c9a86e-088d-4040-8988-af37fa74ad84
<http://symbiota4.acis.ufl.edu/scan/portal/collections/individual/index.php?occid=14702249>, 1 image
SDSU_OP1641, Morphbank Specimen ID: 835725
<http://www.morphbank.net/?id=835725>, 2 images
SDSU_OP1642, GUID: 8558ef80-a8c7-439d-bd93-dba8ec8d11d4
<http://symbiota4.acis.ufl.edu/scan/portal/collections/individual/index.php?occid=14702250>, 1 image
MALE: Measurements of holotype male, with the average and range of all nine specimens measured in parentheses (Suppl. material
Body length 3.40, scute length 2.69 (2.46; 1.97–2.75), scute width 2.58 (2.41; 1.97–2.75), prosoma width 1.88 (1.77; 1.48–1.94). Shoulder tubercles present but small. Scute microgranulate. Integument color without contrast dorsally at midline between prosoma and opisthosoma in all individuals. OC a low broad mound; height 0.14; width 0.59 (0.52; 0.39–0.59). Eye color dark brown; surrounding integument with black pigment. Ventral surface microgranulate. GO length 0.32 (0.31; 0.27–0.32), width 0.28 (0.27; 0.26–0.29).
Mesal SBT of PT relatively low, rounded, with seta near apex of tubercle. PF length 2.0 (1.78; 1.38–2.03), PF depth 0.76 (0.65; 0.44–0.8), with 4–6 ventral spines, with the basal pair prominent, usually 3 enlarged dorsal spines (sometimes 4), and 2 enlarged distal prolateral spines. Pedipalp patella with 2 (one specimen with 3) enlarged prolateral spines and 1 ventroretrolateral spine; tibia with rows of 5 enlarged pro- and retrolateral spines; tarsus with 3 prolateral and 2 retrolateral enlarged spines. PCS with 2 dorsal anterior spines (sometimes 1–3); and with 2 small retrolateral spines (sometimes 1); DCS with 2 rows of small, dorsal, forward-facing acute SBTs. PCS width 0.37, DCS length 1.63, DCS width 0.47.
Leg II length 10.59 (9.88; 8.15–11.0); trochanter 0.58 (0.53; 0.41–0.59), femur 2.66 (2.45; 1.99–2.72), patella 0.84 (0.8; 0.64–0.89), tibia 2.26 (2.14; 1.73–2.4), metatarsus 2.33 (2.22; 1.82–2.48), tarsus 1.93 (1.81; 1.54–1.97); tibia distally and ventrally swollen, with 3–5 rounded SBTs, 2–4 with setae twisted. Tarsal claw as for genus. Tarsal count 5–13–5–6; variation exists in the number of LII tarsal segments.
Penis elongate; glans laterally compressed, dorsal plate extending outward into a more rounded keel shaped protrusion, with two pairs of spines, both pairs appressed to plate (perpendicular to the longitudinal axis of the penis); ventral plate cultriform with dorsally curved apical process.
FEMALE: Measurements of allotype female, with the average and range of all 10 specimens measured in parentheses (Suppl. material
Body length 2.94, scute length 2.35 (2.29; 2.05–2.69), scute width 2.5 (2.52; 2.23–2.75), prosoma width 1.62 (1.61; 1.49–1.76). Integument color darker than males, usually with light contrast dorsally at midline between prosoma and opisthosoma (in 7 of 8 individuals). OC height 0.12; width 0.47 (0.47; 0.4–0.52).
Mesal SBT of PT relatively low, rounded, with seta near apex of tubercle. PF length 1.53 (1.48; 1.39–1.64), PF depth 0.54 (0.53; 0.47–0.61), with 6 or 7 ventral spines (sometimes 5), with the basal pair prominent, with 3 enlarged dorsal spines (sometimes 4), and 2 enlarged distal prolateral spines (sometimes 1). Pedipalp patella with 2 enlarged prolateral spines and 1 ventroretrolateral spine. PCS with 2 anterior spines dorsally, with 2 small retrolateral spines; PCS length 0.30; DCS length 1.19, width 0.28.
LII length 8.66 (8.51; 8.15–9.38); trochanter 0.5 (0.49; 0.44–0.59), femur 2.15 (2.06; 1.95–2.29), patella 0.68 (0.69; 0.66–0.76), tibia 1.78 (1.79; 1.68–1.96), metatarsus 1.95 (1.91; 1.82–2.1), tarsus 1.6 (1.57; 1.55–1.69); Tarsal count 5–11–5-6; variation exists in the number of LII tarsal segments.
GO length 0.3 (0.3; 0.27–0.34), width 0.29 (0.3; 0.27–0.36).
Ovipositor with four lobes, lateral lobes largest with seven apical setae, and a single large spine with a bifurcate tip, ventral lobe smallest.
See Suppl. material
For specific localities, habitats, and microhabitats see Suppl. material
Cryptomaster exhibits a deep molecular phylogenetic break consistent with species level divergence, similar to that observed in many other harvestmen taxa (
Our sampling efforts greatly increased the known range of Cryptomaster, yet both species still appear to have limited distributions. Interestingly, the range for C. leviathan extends across multiple mountain ranges, yet little to no genetic structure exists between these ranges. Conversely, C. behemoth has a particularly small range, yet harbors higher population genetic structure. This could be due to the greater topographic complexity of the central Cascade Range, or these populations may have persisted in their current locations for a longer time compared to C. leviathan populations. A pattern of deep population structure in topographically complex regions is consistent with numerous other arachnid taxa (
Short-range endemic taxa have been shown to help elucidate ancient biogeographic processes (
We thank Adrienne Richart and Erik Ciaccio for assistance with specimen collection, and Erik Ciaccio helped with the SCAN database. Darrell Ubick, Charles Griswold, and Vic Smith provided assistance with morphological analyses and imaging. Stephanie Castillo assisted with molecular data collection. Dean Leavitt and Dave Carlson helped with molecular analyses. Steve Barlow provided SEM support at SDSU. Sara Griffith from the OR Parks & Recreation Department assisted with collecting permits. Comments from Darrell Ubick, Gonzalo Giribet, and one anonymous reviewer helped to improve the manuscript. This research was supported by an NSF grant awarded to M Hedin (DEB 1354558).
Supplementary Table 1–4
Data type: Excel Table
Explanation note:
Table S1. Locality data
Table S2. PCR primer information
Table S3. GenBank accession information and genetic diversity statistics
Table S4. Morphological measurements
Supplementary Figures 1–5
Data type: figures
Explanation note:
Figure S1. Maximum likelihood gene tree for cytochrome c oxidase 1 (COI) locus. Numbers adjacent to nodes indicate bootstrap support greater than 70%.
Figure S2. Maximum likelihood gene tree for Toll locus. Numbers adjacent to nodes indicate bootstrap support greater than 70%.
Figure S3. Maximum likelihood gene tree for F-box/LRR-repeat locus. Numbers adjacent to nodes indicate bootstrap support greater than 70%.
Figure S4. Maximum likelihood gene tree for phosphatase 2A locus. Numbers adjacent to nodes indicate bootstrap support greater than 70%.
Figure S5. Maximum likelihood gene tree for Neuromusculin locus. Numbers adjacent to nodes indicate bootstrap support greater than 70%.