Doryphoribius smokiensis, Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz & Michalczyk, Łukasz, 2007

Bartels, Paul J., Nelson, Diane R., Kaczmarek, Łukasz & Michalczyk, Łukasz, 2007, Doryphoribius smokiensis, a new species of Eutardigrada (Hypsibiidae) from the Great Smoky Mountains National Park, TN, USA (North America), Zootaxa 1646, pp. 59-65 : 61-65

Doryphoribius smokiensis sp. nov.

( Figs. 2–6 )

Material examined: Holotype ( USNM 1107058) and 3 paratypes ( ATBI slide numbers 28aug02-20 -20, 11jun02-16 -32, 11jun02-16 -41): North America, USA, Tennessee, Blount County, Great Smoky Mountains National Park, soil and leaf litter. Holotype and two paratypes ( ATBI slides 11jun02-16 -32 and 11jun02-16 - 42) from dolomitic cave (Rich Mountain Blowhole Cave, N 35o 38.777’, W 83o 48.531’, 712 m asl, 11.06.2002); one paratype ( ATBI slide 28aug02-20 -20) from forest floor in Tremont permanent ATBI plot (N 35o 38.417’, W 83o 41.905’, 544 m asl, 28.08.2002), leg. P.J. Bartels.

Description (measurements of the holotype, USNM 1107058). Body length 305.6 ( Fig. 2 ). Body colour unknown, eyes absent. Cuticle with polygonal design (polygons about 1.0 in diameter) on dorsal and lateral side of the body, gibbosities absent ( Fig. 3 ). Polygons are not strongly evident and sometimes may be missing. Cuticle on legs smooth. Bucco-pharyngeal apparatus of the Doryphoribius type: peribuccal lamellae and papulae absent, ventral lamina present ( Fig. 4 ). Oral cavity armature very simple and composed of only one anterior and posterior band of small round teeth. Mouth antero-ventral. Buccal tube 32.2 long and 8.5 [26.4] (external); 7.1 [22.0] (internal) wide. Ventral lamina 13.6 [42.2] long. At the end of buccal tube triangular or rounded pharyngeal apophyses present. Stylet supports inserted on buccal tube at 23.9 [74.2]. Pharyngeal bulb spherical (31.0 x 28.6) with two macroplacoids (length configuration 1(longest)-2(shortest)). Microplacoid and septulum absent. First macroplacoid with distinct central constriction, 7.7 [23.9] long; second 3.6 [11.2] long and without constriction. Pharyngeal apophyses 3.6 [11.2] long. Macroplacoid row 13.9 [43.2] long.

Claws of the Isohypsibius type similar in size and shape ( Figs. 5–6 ). Primary branches of claws with welldeveloped accessory points. Lunules and other cuticular thickenings on legs absent. Claw lengths: leg I: external: basal claw 2.0 [6.2], primary branch 5.2 [16.1], secondary branch 4.0 [12.4]; internal: basal claw 1.8 [5.6], primary branch 5.0 [15.5], secondary branch 3.5 [10.9]; leg II: not measurable; leg III: external: basal claw 2.3 [7.1], primary branch 7.6 [23.6], secondary branch 3.6 [11.2]; internal: basal claw 2.2 [6.8], primary branch 5.4 [16.8], secondary branch 4.3 [13.4]; leg IV: anterior (external): basal claw 1.9 [5.9], primary branch 5.1 [15.8], secondary branch 3.5 [10.9]; posterior (internal): basal claw 2.1 [6.5], primary branch 6.6 [20.5], secondary branch 3.5 [10.9].

Eggs unknown.

Remarks. Measurements and pt values of selected morphological structures for all specimens are given in Table 1 .

Etymology. The name ‘ smokiensis ’ refers to the Great Smoky Mountains National Park.

Type depositories. The holotype ( USNM 1107058) is deposited in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. One paratype ( ATBI 28aug02-20 -20) is deposited in the GSMNP collection, one ( ATBI 11jun02-16 -32) in the Nelson Collection, ETSU, Johnson City, TN, USA, and one ( ATBI 11jun02-16 -41) in the Department of Animal Taxonomy and Ecology, A. Mickiewicz University, Umultowska 89, Poznań, Poland.

Differential diagnosis. Doryphoribius smokiensis sp. nov. differs from the two other species that have two macroplacoids and a sculptured dorsal cuticle without gibbosities by the presence of a very high buccal tube pt ratio (>20.0 in the new species and <15.0 in the two similar species) and by the absence of eyes.

Additionally Doryphoribius smokiensis sp. nov. differs from:

1. Doryphoribius flavus ( Iharos, 1966) by: a smaller body size (178.7–305.6 in D. smokiensis sp. nov. and 360.0–700.0 in D. flavus ), the absence of gibbosities and sculpture on legs, lack of punctation on the dorsal side of the body, finer dorso-lateral cuticular sculpture, distinctly smaller claws (<9.0 in the new species and>20.0 in D. flavus ), the absence of enlarged bases of claws.

2. Doryphoribius polynettae Biserov, 1988 by: the absence of ventral sculpture, the absence of lunules and enlarged bases of claws, a different buccal cavity armature (a band of small round teeth in D. smokiensis sp. nov. and median tooth and a few smaller teeth on the dorsal side and a few small teeth on the ventral side in D. polynettae ), a shorter buccal tube (24.4–32.2 in D. smokiensis sp. nov. in specimens 178.5–305.6 long and 38.6–45.0 in D. polynettae in specimens 255.0–540.0), wider buccal tube (6.2–8.5 in D. smokiensis sp. nov. in specimens 178.5–305.6 long and 3.0– 4.6 in D. polynettae in specimens 255.0–540.0), shorter posterior (internal) claws IV (<9.0 in the new species and>10.0 in D. polynettae ), shorter base of the posterior (internal) claws IV (about 2.0 in the new species and>4.5–11.0 in D. polynettae ).

Ecological comments. Doryphoribius smokiensis sp. nov. seems to be a very rare species, found exclusively in soil and leaf litter. The entire tardigrade inventory of the GSMNP includes over 600 samples from a wide diversity of habitats, with approximately eleven thousand individuals identified so far. Yet, only four specimens of Doryphoribius smokiensis sp. nov. have been found from two samples. Although the holotype was found in a cave, it is doubtful that this is a cave-adapted species ( Bertolani 2002). The cave sample was near the cave entrance and included leaf litter originating from outside the cave. Furthermore, an additional paratype was found in forest floor leaf litter/soil.

In comparison, Doryphoribius flavus , has been found in Europe, Asia, Africa, and Central America ( McInnes 1994) and was originally found in moss subjected to desiccation ( Iharos 1966), while Doryphoribius polynettae has been found only in Russia so far in a small lake and in mosses ( Sphagnum sp., Politrychum juniperinum) near the lake.

Figures

FIGURES 2 – 3. Doryphoribius smokiensis sp. nov.: 2, habitus (holotype); 3, dorsal cuticle with polygonal sculpture (paratype). (PCM)

FIGURES 4 – 6. Doryphoribius smokiensis sp. nov.: 4, bucco-pharyngeal apparatus (ventral view, paratype); 5 – 6, claws (5, leg III; 6, leg IV; holotype). Scale on Figs. 5 – 6 same as on Fig. 4; PCM.

Tables

TABLE 1. Measurements (in µm) and pt values of selected morphological structures of specimens of Doryphoribius smokiensis sp. nov. mounted in Hoyer’s medium (in the body length order). Abbreviations: bc = basal claw, pb = primary branch, sc = secondary branch, ext = external, int = internal, ant = anterior, post = posterior.

Character	Paratype 1 ATBI 28aug02-20-20 µm pt	Paratype 2 ATBI11jun02-16-32 µm pt	Paratype 3 ATBI 11jun02-16-41 µm pt	Holotype USNM 1107058 µm pt
Body	178.7 687.3	182.4 747.5	286.1 1051.8	305.6 949.1
Buccal tube Stylet support insertion point	26.0 – 19.5 75.0	24.4 – 18.3 75.0	27.2 – 20.2 74.3	32.2 – 23.9 74.2
Buccal tube external width Buccal tube internal width	6.3 24.2 5.0 19.2	6.2 25.4 5.2 21.3	7.0 25.7 6.0 22.1	8.5 26.4 7.1 22.0
Ventral lamina	11.0 42.3	11.0 45.1	11.5 42.3	13.6 42.2
Macroplacoid 1 Macroplacoid 2	5.9 22.7 3.0 11.5	5.6 23.0 3.1 12.7	6.7 24.6 3.2 11.8	7.7 23.9 3.6 11.2
Macroplacoid row	11.7 45.0	10.3 42.2	12.9 47.4	13.9 43.2
Claw 1 - bc (ext) Claw 1 - pb (ext)	????	????	????	2.8 8.7 5.2 16.1
Claw 1 - sb (ext)	??	??	??	4.0 12.4
Claw 1 - bc (int) Claw 1 - pb (int)	????	?? 3.7 15.2	????	2.7 8.4 5.0 15.5
Claw 1 - sb (int)	??	2.7 11.1	??	3.5 10.9
Claw 2 - bc (ext) Claw 2 - pb (ext)	????	????	????	????
Claw 2 - sb (ext)	??	??	??	??
Claw 2 - bc (int) Claw 2 - pb (int)	????	?? 4.2 17.2	1.8 6.6 3.9 14.3	2.8 8.7 ??
Claw 2 - sb (int)	??	2.7 11.1	3.1 11.4	??
Claw 3 - bc (ext) Claw 3 - pb (ext)	????	????	????	2.8 8.7 7.6 23.6
Claw 3 - sb (ext)	??	??	??	3.6 11.2
Claw 3 - bc (int) Claw 3 - pb (int)	????	????	????	2.6 8.1 5.4 16.8
Claw 3 - sb (int)	??	??	??	4.3 13.4
Claw 4 - bc (ant/ext) Claw 4 - pb (ant/ext)	????	????	????	2.5 7.8 5.1 15.8
Claw 4 - sb (ant/ext)	??	??	??	3.5 10.9
Claw 4 - bc (post/int) Claw 4 - pb (post/int)	????	????	????	2.5 7.8 6.6 20.5
Claw 4 - sb (post/int)	??	??	??	3.5 10.9