Arachnids of North Carolina
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Fumontana deprehendor - No Common Name     Sole representative of Triaenonychidae in NC NC Records BugGuide Account Public View
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Distribution Records
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Vetting Levels
Adult phenology:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

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synonym
taxonomic_comments The sole member of this genus, which is endemic to the Southern Appalachians (Kury, 2003). This is also the only member of the Triaenonychidae in eastern North America, with its closest relatives occurring in western North America and the Southern Hemisphere (Shear, 1977). Based on its isolated range and unique structural features, Shear speculated that Fumontana is an ancient relict, originating when its taxonomic line was much more widespread prior to the splitting apart of the continents. This hypothesis was further supported by the DNA analysis conducted by Thomas and Hedin (2008), who showed a closer link to the South African and Australian members of this group than to those in western North America (in agreement with Shear, 1977).
species_comment Thomas and Hedin (2008) found little morphological differentiation across the range of Fumontana but discovered strong genetic divergence, with five genealogically and geographically separate clades identified. Based on molecular "clock" estimates, these lineages may have differentiated as long ago as the Pliocene or beginning of the Pleistocene. These differences raise the question as to whether these lineages should be treated as cryptic species. Whatever their taxonomic status, however, conserving all of these groups is consistent with the overall goals of maintaining biodiversity.
id_comments A minute, spiny-legged Armored Harvestman. The color is a translucent yellow orange, with the females paler than the males (Shear, 1977). No markings are present, in contrast to Theromaster brunneus, which is mottled with yellow and brown. Bishopella is fairly uniform but is a darker reddish orange.
total_length 1.46 mm, scute, male holotype; 1.20 mm, scute, female paratype (Shear, 1977)
structural_features Easily distinguished based on the large spine-tipped tubercles on its first two pair of legs; smaller spines are located on the other two pairs of legs. Other small harvestmen in our mountains have much smaller spinses on their legs, if any at all. See description given by Shear (1977) for a detailed description of other structural differences, along with illustrations.
silk_web
fld_guide_descriptions
online_photos BugGuide
prey
predators
behavior
distribution_reference Shear (1978)
technical_reference Shear (1977)
adult_id 1 identifiable by photo 2 identifiable by photo of specific features and/or supplementary info 3 identifiable from specimen only
abundance In some areas searched by Thomas and Hedin (2006), individuals were fairly easy to find, with multiple individuals sometimes found within the same log. In other areas of seemingly good habitat, however, no individuals were found, particularly towards the southwestern edge of their range.
distribution_comments The distribution of the five genealogical and geographically separate lineages identified by Thomas and Hedin (2008) is similar to those described for other cryophlic arthropod taxa as well as Plethodontid salamanders for which the Southern Appalachians is a region of high endemism. As in those groups, lineages in Fumontana are divided by the major rivers of this region, including the Little Tennessee, Tuckaseegee, Pigeon, and French Broad. These breaks represent not only water barriers but also major drops in elevation, with broad, low basins, such as the Asheville Basin, also representing major gaps in habitat.
checklist_mt_high
>=4,000 ft.
Regular
Frequent
Infrequent
Occasional
Seldom
Frequency
checklist_mt_low
<4,000 ft.
Regular
Frequent
Infrequent
Occasional
Seldom
checklist_pd
Piedmont
Regular
Frequent
Infrequent
Occasional
Seldom
checklist_cp
Coastal Plain
Regular
Frequent
Infrequent
Occasional
Seldom
habitat The populations originally discovered by Shear (1977, 1978) were located in mature stands of cove forest, the one in Joyce Kilmer Memorial Forest a virgin stand. Thomas and Hedin (2006) concentrated their searches -- which were very productive -- in hemlock-dominated stands, probably also mainly cove forests.
observation_methods Thomas and Hedin (2006) found most of their specimens by tearing apart wet, rotten logs, especially of hemlocks. They also found at least some in other situations, including under rocks.
state_protection Arachnids are not protected under state law, although permits are needed to collect them in State Parks and other public and private nature preserves
NHP_ranks [G2G3] [S2S3]
NHP_status W3->[SR]
status_comments Following Shear's (1977, 1978) original discovery of this species, it was considered to be quite rare, as reflected in the NatureServe rank of G1G2. However, the survey conducted by Thomas and Hedin (2006) greatly expanded the number of known sites as well as increased the overall range of this species. While this expansion in its range and area of occupancy increases its apparent viability, it still has a very small global range and appears to be vulnerable to the impacts of global climate change, including both warming and drying. Alteration of cove forests due to the impacts of the Hemlock Wooly Adelgid are also likely to have significant impacts on this species (Thomas and Hedin, 2008). Given the very low vagility of this species, local extirpation events will take a long time to recover, if ever. Even temporary disturbances to its habitat -- e.g., clear-cuts, fires, local droughts -- can therefore have a strong cumulative effect over time. This low vagility is also reflected in the strong genomic separation between several of the mountain ranges and river valleys: loss of these populations means the loss of entire clades (or perhaps cryptic species) (Thomas and Hedin, 2008). In considering all of these factors, we recommend that this species be considered of high conservation concern at both the global and state level and managed and/or monitored accordingly Individual attention should be given to each of the five clades identified so far, whether they are considered as "evolutionarily significant units" or full, if cryptic, species.