Testudacarus rectangulatus O'Neill & Dowling

O'Neill, Joseph C., Fisher, J. Ray, Nelson, Whitney A., Skvarla, Micheal J., Fisher, Danielle M. & Dowling, Ashley P. G., 2016, Systematics of testudacarine torrent mites (Acari, Hydrachnidia, Torrenticolidae) with descriptions of 13 new species from North America, ZooKeys 582, pp. 13-110 : 80-82

Taxon classification Animalia Trombidiformes Torrenticolidae

Testudacarus rectangulatus O'Neill & Dowling sp. n.

Type series.

Holotype (1♂): Washington, USA: 1♂ from Mason County, Olympic National Forest, Cabin Creek, by Hamma Hamma River (47°35'44.00"N, 123°7'39.00"W), 22 July 2013, by JC O’Neill and WA Nelson, JNOW13-0722-004 (Specimen 138494 - DNA#1521)

Type deposition.

Holotype (1♂) deposited at CNC

Diagnosis.

Since morphological variation is limited, a combination of morphology and distribution is best used to diagnosed members of the complex. These mites occur in the Olympic Mountains, while Testudacarus elongatus occur in Washington within and east of the Cascade Mountains, and Testudacarus oblongatus occur along the western Coast of Washington, Oregon, California, and British Columbia. Additionally, both Testudacarus elongatus and these mites differ from Testudacarus oblongatus in having more robust lateral platelets; most notably, lateral-platelet-4 tends to be larger in these two species than Testudacarus oblongatus , and is in direct or near direct contact with lateral-platelet-2. Reversely, Testudacarus oblongatus generally have less robust platelets and a smaller lateral-platelet-4 that has a noticeable gap between it and lateral-platelet-2. Limited specimens were found of Testudacarus elongatus and Testudacarus rectangulatus , but Testudacarus rectangulatus appear to have leg and pedipalp measurements roughly 10% larger than Testudacarus elongatus even between individuals of similar idiosoma size. More data is needed to better diagnose these species.

Description.

Female (n=0) unknown.

Male (n=1) with characteristics of genus with following specifications.

Gnathosoma - Subcapitulum [173 ventral length; 108 dorsal length; 105 tall] ovoid with short rostrum. Chelicerae [150 long] unmodified with lightly curved fangs [33-37 long]. Pedipalp [249 long] unmodified. Trochanter [35 long; 34 wide]. Femur [60 long; 48 wide]. Genu [56 long; 40 wide]. Tibia [75 long; 25 wide]. Tarsus [23 long; 12 wide].

Dorsum (Fig. 46) - [773 long; 495 wide] oblong and colorless. Dorsal plate [649 long; 413 wide]. Dorso-glandularia-4 [173 apart] lateral to [41] and anterior to [63] muscle scars. Platelets colorless. Anterio-medial platelet [183 long; 108 wide] trapeziform to nearly triangular (posterior margin strongly shortened). Anterio-lateral platelets [216 long; 114 wide] near rectangular. Lateral platelets as follows: lateral-1 [40 long; 45 wide]; lateral-2 [161 long; 41 wide]; lateral-3 [39 long; 23 wide]; lateral-4 [165 long; 40 wide]; lateral-5 [55 long; 34 wide]; lateral-6 [112 long; 49 wide]; lateral-7 [69 long; 37 wide].

Venter (Fig. 46) - [929 long; 492 wide] oblong. Primary sclerotization [855 long]. Gnathosomal bay [83 dorsal length; 162 ventral length; 89 wide]. Coxal field [577 long; 390 wide]. Coxa-I [278 long; 116 midlength]. Coxa-II + III [122 distance to top of coxa-II; 203 distance to top of coxa-III; 439 distance to bottom of coxa-III; 317 total length]. Coxa-IV [375 distance to top; 201 total length]. Genital field [461 distance to top; 647 distance to bottom; 186 total length; 133 width; 299 distance from gnathosomal bay; 183 distance from coxa-I; 208 distance to excretory pore; 282 distance to caudad]. Genital skeleton [250 long]. Distance to excretory pore [855].

Legs - colorless. Total leg and podomere lengths as follows: Leg-I [603 total; trochanter 61; basifemur 103; telofemur 89; genu 116; tibia 124; tarsus 108]. Leg-II [610 total; trochanter 63; basifemur 101; telofemur 85; genu 115; tibia 126; tarsus 120]. Leg-III [674 total; trochanter 63; basifemur 110; telofemur 86; genu 130; tibia 145; tarsus 137]. Leg-IV [870 total; trochanter 87; basifemur 123; telofemur 130; genu 179; tibia 189; tarsus 160].

Etymology.

Specific epithet rectangulatus (rectangulum, L. straight angle) refers to the boxy, elongate idiosoma of adults.

Distribution.

One specimen found in Mason County in the Olympic Mountains, Washington.