Doryphoribius doryphorus ( Binda and Pilato, 1969 )

Bartels, P. J., Nelson, D. R., Kaczmarek, Ł. & Michalczyk, Ł., 2008, Three new species and one new record of the genus Doryphoribius Pilato, 1969 (Tardigrada: Eutardigrada: Hypsibiidae) from the Great Smoky Mountains National Park (Tennessee, USA), Journal of Natural History 42 (41 - 42), pp. 2595-2608 : 2606-2607

Doryphoribius doryphorus ( Binda and Pilato, 1969)

Six specimens of this species were found in stream periphyton from the low-gradient section of Abram’s Creek with limestone bedrock. The specimens perfectly correspond to the original description of Binda and Pilato (1969), (ATBI slide numbers: 13apr03-16-1, 8, 10–11, 13–14.).

Ecological comments

All five species of Doryphoribius in our collection [ D. smokiensis (Bartels et al. 2007) , D. longistipes sp. nov., D. minimus sp. nov., D. tergumrudis sp. nov. and D. doryphorus ] appear to be rare and generally restricted to the Cades Cove region of the GSMNP (see Figure 5 ). The current database for the GSMNP tardigrade collection now includes 10,702 specimens identified to species from over 400 samples throughout the park. Collectively, there are only 29 specimens of Doryphoribius .

Three specimens of Doryphoribius smokiensis (Bartels et al., 2007) were found in soil and leaf litter in the dolomitic caves of Cades Cove, while one specimen was found in forest soil and leaf litter outside the limestone-based area of the park, 10 km from the caves (Tremont ATBI plot, see Figure 5 ). Three specimens of D. longistipes sp. nov. were found in periphyton (but not sediment) from Abram’s Creek just upstream from the limestone-dominated section of Cades Cove. Seven additional specimens of D. longistipes were found in soil and leaf litter from the entrance to Gregory’s Cave. Five specimens of D. minimus sp. nov. were collected from lichens on the external walls of Gregory’s and Bull Caves. Only one specimen of D. tergumrudis sp. nov. has been found in the entire ATBI collection, and it was collected in the periphyton from a limestone-based section of Abram’s Creek. Six specimens of Doryphoribius doryphorus were also found exclusively in periphyton samples from the limestone-based section of Abram’s Creek.

Doryphoribius appears to be rare in most collections, and authors do not generally indicate geological associations ( Binda and Pilato 1969; Beasley and Pilato 1987; Dastych 1988). Dastych (1988) specifically addresses the bedrock geology, but he was unable to determine any geological preferences of Doryphoribius species in his large collection in Poland because of their rarity. In the GSMNP in this present study 24 of 29 specimens of Doryphoribius were associated with limestone bedrock suggesting that this may be an important factor determining the distribution of this genus. Ecological studies investigating causes of species- or genus-level rarity in tardigrades would be valuable ( Münzbergová, 2005).

Figures

Figure 5. Topographic map (hillshade view) of the Great Smoky Mountains National Park indicating sites where Doryphoribius longistipes sp. nov., Doryphoribius minimus sp. nov., Doryphoribius tergumrudis sp. nov., Doryphoribius doryphorus (Binda and Pilato, 1969) and Doryphoribius smokiensis Bartels et al., 2007 were collected. Circles indicate terrestrial sample sites, triangles indicate aquatic sample sites. Closed circles and triangles are sites that yielded Doryphoribius, open circles and triangles did not.