Torrenticola Trimaculata N. Sp. (Parasitengona: Torrenticolidae), a Three-Spotted Water Mite from Eastern North America: Taxonom
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Torrenticola trimaculata n. sp. (Parasitengona: Torrenticolidae), a three-spotted water mite from eastern North America: taxonomic history, species delimitation, and survey of external morphology R. Fisher, D.M. Fisher, W.A. Nelson, J.C. O’Neill, M.J. Skvarla, R. Ochoa, G.R. Bauchan, A.J. Radwell, A.P.G. Dowling To cite this version: R. Fisher, D.M. Fisher, W.A. Nelson, J.C. O’Neill, M.J. Skvarla, et al.. Torrenticola trimaculata n. sp. (Parasitengona: Torrenticolidae), a three-spotted water mite from eastern North America: taxonomic history, species delimitation, and survey of external morphology. Acarologia, Acarologia, 2015, 55 (1), pp.71-116. 10.1051/acarologia/20152155. hal-01548355 HAL Id: hal-01548355 https://hal.archives-ouvertes.fr/hal-01548355 Submitted on 27 Jun 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution - NonCommercial - NoDerivatives| 4.0 International License ACAROLOGIA A quarterly journal of acarology, since 1959 Publishing on all aspects of the Acari All information: http://www1.montpellier.inra.fr/CBGP/acarologia/ [email protected] Acarologia is proudly non-profit, with no page charges and free open access Please help us maintain this system by encouraging your institutes to subscribe to the print version of the journal and by sending us your high quality research on the Acari. Subscriptions: Year 2017 (Volume 57): 380 € http://www1.montpellier.inra.fr/CBGP/acarologia/subscribe.php Previous volumes (2010-2015): 250 € / year (4 issues) Acarologia, CBGP, CS 30016, 34988 MONTFERRIER-sur-LEZ Cedex, France The digitalization of Acarologia papers prior to 2000 was supported by Agropolis Fondation under the reference ID 1500-024 through the « Investissements d’avenir » programme (Labex Agro: ANR-10-LABX-0001-01) Acarologia is under free license and distributed under the terms of the Creative Commons-BY-NC-ND which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited. Acarologia 55(1): 71–116 (2015) DOI: 10.1051/acarologia/20152155 Torrenticola trimaculata n. sp. (Parasitengona: Torrenticolidae), a three-spotted water mite from eastern North America: taxonomic history, species delimitation, and survey of external morphology J. Ray FISHER1*, Danielle M. FISHER1, Whitney A. NELSON1, Joseph C. O’NEILL1, Michael J. SKVARLA1, Ron OCHOA2, Gary R. BAUCHAN2, Andrea J. RADWELL1 and Ashley P.G. DOWLING1 (Received 22 December 2014; accepted 17 February 2015; published online 30 March 2015) 1 Department of Entomology, University of Arkansas, Fayetteville, AR 72701, USA. (* Corresponding author) jrfi[email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected] 2 USDA-ARS, 10300 Baltimore Ave., Bldg. 012, 5th St., BARC-West, Beltsville, MD 20705, USA. [email protected], [email protected] ABSTRACT — Torrenticola trimaculata Fisher n. sp. is described from eastern North America as the first in a series of descriptions on Torrenticolidae. As such, the study includes expanded discussions of methods, early taxonomic history, and numerous images surveying external morphology using a diversity of imaging methods. Species hypotheses were supported with analysis of the "barcoding" region of COI. Torrenticola trimaculata is found to be a wide-ranging, variable species with two distinct morphs that do not coexist locally. Also, we report the first record of the diatom, Cocconeis placentula Ehrenberg 1838, as epiphytic on water mites. KEYWORDS — Trombidiformes; Prostigmata; Hydrachnidia; Hydrachnidiae; LT-SEM; Cocconeidaceae INTRODUCTION Herein, we describe Torrenticola trimaculata Fisher n. sp. (Fig. 1) from eastern North Amer- The present study is the first in a series of descrip- ica, which contains two color morphs (Fig. 2). This tions from an ongoing taxonomic project on North description is intended as a reference for future de- American Torrenticolidae Piersig, 1902. We have scriptions that will be streamlined for time/space direct access to specimens across the United States efficiency. Toward this end, we have included back- and Canada from the substantial holdings of the ground information intended to help future stu- Canadian National Collection (CNC). These exten- dents of Torrenticolidae including discussions of sive collections provide ample specimens preserved taxonomic history, methods, morphology, and a siz- using traditional methods as material preserved in able reference list. ethanol for molecular analysis. Our ultimate goal is to open Torrenticolidae to other researchers so this Torrenticolidae are common and distinctive wa- ubiquitous taxon can be explored with other disci- ter mites found worldwide, excepting Antarctica. plines like stream ecology, behavior, and environ- Larvae are ectoparasites of adult midges (esp. Chi- mental assessment. ronomidae) and adults are reported to feed on http://www1.montpellier.inra.fr/CBGP/acarologia/ 71 ISSN 0044-586-X (print). ISSN 2107-7207 (electronic) Fisher J.R. et al. FIGURE 1: Torrenticola trimaculata n. sp. habitus of types (montaged from iPhone steromicrographs): A – Holotype (female): dorsal and ventral habitus, Morph 1; B – Allotype (male): dorsal and ventral habitus, Morph 1. Coloration is not indicative of sex. 72 Acarologia 55(1): 71–116 (2015) FIGURE 2: Torrenticola trimaculata n. sp. morphs (A-D compound light micrographs; E-F stereomicrographs): A – Morph I female, note large dorsal spots, pigmented gnathosoma and venter (within area of primary sclerotization), and orange legs; B – Morph II female, note small dorsal spots, and colorless gnathosoma, legs, and venter (except for genital plate); C – Morph I male (note same coloration as female); D – Morph II male (note same coloration as female but with hind coxae pigmented); E-F – Dorsal habitus of Morph I & II, respectively. 73 Fisher J.R. et al. microcrustaceans (Goldschmidt 2007, Smith et al. east. However, based on previous collections we 2010). As is typical for lotic-dwelling water mites have identified many putative species from across (Smith et al. 2010), torrenticolids are heavily scle- the continent, highlighting the need for this type of rotized, dorsoventrally flattened, and possess lati- research. grade legs with robust tarsal claws for crawling rather than swimming. Many torrenticolids have distinct color patterns, the adaptive utility of which remains unknown, but perhaps serves as disrup- MATERIALS AND METHODS tive coloration. Most are denizens of fast-flowing streams, but several species occupy lentic habitats; Sampling these are considered recent invasions since they re- tain lotic-typical morphology. As a group, Torrenti- Mites were collected using protocol detailed in colidae are among the most abundant and species- Smith et al. (2010, p.516-518). This involves dig- rich animals in fast-flowing streams; nevertheless, ging a trench (typically 1-2m) upstream of a 250 µm- most species remain unknown. mesh collection net. Digging depth is determined Torrenticolidae comprises six genera, two of by a lack of organic debris visible in the water col- which are speciose (Torrenticola Piersig, 1896 and umn during a dig, but sediment is generally dis- Monatractides Viets, 1926) and four others are less turbed several feet below the substrate surface. To than thirty species combined (Testudacarus Wal- reduce sediment accumulation, the sample is trans- ter, 1928; Pseudotorrenticola Walter, 1906; Neoatrac- ferred into either a gallon bag or large jar. The con- tides Lundblad, 1941; and Stygotorrenticola Peši´c tainer is swirled so that mites and organic debris and Gerecke, 2014). Torrenticola–the largest genus– are suspended in the water column and sediment contains nearly 250 described species worldwide, remains at the bottom. The top solution is then with 76 species known from North America. Most poured through a stacked combination of coarse North American species are from Central Amer- (2mm) and fine (250 µm) sieves. This process is re- ica, as Goldschmidt (2007) described 36 new species peated until organic matter is no longer visible in from Costa Rica (raising the total number known the jar. The course sample is discarded and the fine from Central America from 19 to 55). sample is transferred to a water-filled site-specific container. The container is cooled until the samples In North America, only 22 described Torrenti- can be processed, thus keeping the mites alive. cola occur north of Mexico, most of which were described by Ruth Marshall (1869-1955) and Her- Processing involves pouring the live material bert Habeeb (1917-1987). Marshall described five of through a 250 µm sieve or hand net and transferring the nine known western species (four from Califor- the resulting clump to a shallow water-filled white nia and one from Wyoming), as well as T. occiden- tray (such as darkroom developing trays). Most wa- talis, which is now known from Indiana, Ohio, and ter mites swim away from