AQUATIC MITES: FROM GENES TO COMMUNITIES AQUATIC MITES FROM GENES TO COMMUNITIES Editor HEATHER C. PROCTOR University ofA lberta, Edmonton, Canada Reprinted from Experimental and Applied Acarology Volume 34 Numbers 1-2, 2004 . . , ~ Springer-Science+B usiness Media, B.V. A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-90-481-6710-4 ISBN 978-94-017-0429-8 (eBook) DOI 10.1007/978-94-017-0429-8 Prill ted 011 acid-Fee paper All Rights Reserved © 2004 Springer Science+ Business Media Dororecht Originally published by Kluwer Academic Publishers in 2004 Softcover reprint of the hardcover 1s t edition 2004 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner. Cover photograph: With their often brilliant colours, water mites are strikingly con spicuous compared to most other freshwater invertebrates. Many species, such as Limnochares americana Lundblad (Limnocharidae), are bright red, and are also dis tasteful to fish. The origin and function of this apparent aposematism are discussed in Proctor & Garga in this volume. Photo by Heather Proctor; L. americana specimens from Hasse Lake, Alberta, Canada. TABLE OF CONTENTS H.C. Proctor / Aquatic mites: from genes to communities - an introduction 1-2 G. Sevik / The biology and life history of arctic populations of the littoral mite Ameronothrus lineatus (Acari, Oribatida) 3-20 DJ. Marshall and P. Convey / Latitudinal variation in habitat specificity of ameronothrid mites (Oribatida) 21-35 1. Bartsch / Geographical and ecological distribution of marine halacarid genera and species (Acari: Halacaridae) 37-58 1. Rey, B.A. Dorda and A.G. Valdecasas / Traditional water mite fixatives and their compatibility with later DNA studies 59-65 D.D. Edwards, D.E. Deatherage and B.R. Ernsting / Random amplified polymorphic DNA analysis of kinship within host associated populations of the symbiotic water mite Unionicola Joili (Acari: Unionicolidae) 67-77 M.R. Forbes, K.E. Muma and B.P. Smith / Recapture of male and female dragonflies in relation to parasitism by mites, time of season, wing length and wing cell symmetry 79-93 P. Martin / Specificity of attachment sites of larval water mites (Hydrachnidia, Acari) on their insect hosts (Chironomidae, Diptera) - evidence from some stream-living species 95-112 B.P. Smith and J. Florentino / Communication via sex pheromones within and among Arrenurus spp. mites (Acari: Hydrachnida; Arrenuridae) 113-125 H.C. Proctor and N. Garga / Red, distasteful water mites: did fish make them that way? 127-147 A. Boulton, M. Harvey and H. Proctor / Of spates and species: responses by interstitial water mites to simulated spates in a subtropical Australian river 149-169 T. Goldschmidt/Environmental parameters determining water mite assemblages in Costa Rica 171-197 A. Di Sabatino, A. Boggero, F.P. Miccoli and B. Cicolani / Diversity, distribution and ecology of water mites (Acari: Hydrachnidia and Halacaridae) in high Alpine lakes (Central Alps, Italy) 199-210 Experimental and Applied Acarology © 2004 Kluwer Academic Publishers. Aquatic mites: from genes to communities - an introduction Although chelicerates originated in the sea, the vast majority of extant species are terrestrial. Since the invasion of land, only one species of spider has taken up the old subaquatic life (Argyroneta aquatica), and there are a few intertidal pseudoscorpions that can withstand inundation. It is among the mites that one finds the greatest number of species, indeed, of entire superfamilies, that have taken up a watery existence. Each aquatic taxon has close terrestrial relatives, and sometimes displays rudiments of terrestrial adaptations (e.g. closed stigmatal openings), and so it seems that invasion of the aquatic environment by mites has occurred repeatedly. Approximately 7000 species from the Mes ostigmata, Astigmata, Oribatida and especially the Prostigmata, now live in marine and freshwater habitats. There are even a few ticks that parasitize marine iguanas and sea snakes! In part because of their unusual lifestyle, and likely also because few have any obvious agricultural or medical importance, aquatic mites are usually relegated to habitat-specific journals together with various other aquatic invertebrates, and have rarely appeared in the pages of Experimental and Applied Acarology. We hope that this special issue will help to bring aquatic mites into 'main stream' Acarology. It is the product of a brief conversation between HP and EAA-editor Jan Bruin at the poster session of the International Congress of Acarology in Merida, Mexico, in September 2002. Jan asked Heather whether she would be interested in acting as guest editor for a special issue of Experi mental and Applied Acarology dealing with aquatic mites. Saying 'yes' required but a moment's consideration; bringing the issue into fruition has been a rather longer process! But the result was worth it. Here are 12 new papers that cover a wide range of taxa and a great diversity of themes. Marine and freshwater oribatids are featured in papers by Marshall and Convey and by S0vik, where we learn that the Arctic species Ameronothrus lineatus takes 5 years to reach maturity (twice as long as the average lifespan of many arctic rodents!). A summary of current knowledge about the distribution and ecology of marine halacarids is presented by Bartsch; this information will be extremely valuable given the increasing transportation of marine taxa by shipping, and the importance of assigning point of origin to animals found in ballast water. The remaining papers deal with the most species-rich group of aquatic mites, the 'true' water mites (Prostigmata: Parasitengona). These range from studies of genes (Rey et aI., Edwards et aI.), larval parasitism (Forbes et aI., Martin), mating behaviour (Smith and Florentino), evolution of warning colouration (Proctor and Garga), and relationship between environmental factors and 2 community composItion (Di Sabatino et aI., Boulton et aI., Goldschmidt). These articles raise as many interesting questions as they answer, and should provoke more studies of the biology of freshwater and marine Acari. I thank the authors and the many excellent reviewers who helped to create this special issue. Heather Proctor Department of Biological Sciences University of Alberta Edmonton Alberta T6G 2E9 Canada e-mail: [email protected] ... Experimental and Applied Acarology 34: 3-20, 2004. " © 2004 Kluwer Academic Publishers. Printed in the Netherlands. The biology and life history of arctic populations of the littoral mite Ameronothrus lineatus (Acari, Oribatida) GULDBORG S0VIK Institute of Marine Research, Tromso branch, P.O. Box 6404, N-9294, Tromso, Norway; (e-mail: [email protected]; phone: + 47-77-60-9753; fax: +47-77-60-9701) Key words: Latitudinal distribution, Life cycle, Microevolutionary adaptations, Multi-instar aggregations, Population dynamics, Reproductive biology, Temperature Abstract. The present study attempts to elucidate possible microevolutionary adaptations of life history traits of high-latitude populations of the hoi arctic, littoral oribatid mite Ameronothrus lineatus by comparing arctic and temperate populations. Additionally, the paper provides an overview of the limited research on general ecology and population biology of arctic populations. In the Arctic the larviparous A. lineatus has a 5-year life cycle (Iarva-to-Iarva), and adults survive a further 2-3 years. High survival to maturity is consistent with a low lifetime reproductive output of ca. 20 larvae. The life history can be regarded as an extreme version of the typical oribatid life history. However, several life-history features suggest specific adaptations of arctic populations. In particular, the pre-moult resting stage is synchronized with the warmest part of the arctic summer, which shortens this vulnerable part of development. High reproductive investment by females at relatively low temperatures may represent a physiological adaptation to the cool arctic summer. Finally, prolonged cold exposure positively affects reproduction and survival the following sum mer, suggesting adaptation of the species to the highly seasonal arctic environment. On the other hand, the ability of all life-cycle stages to overwinter, and a flexible life history with the species being able to take advantage of favourable climatic conditions to accelerate development and larviposition, seem to be ancestral features. Thus, the success of A. lineatlls in arctic habitats is probably attributable to a combination of derived and ancestral life-history traits. Studies of conspecific temperate populations are required to elucidate further local adaptations of arctic populations. Introduction The diversity of the arctic arthropod fauna is fairly well known (Danks 1981; Coulson and Refseth 2004), but information on population biology and life history strategies of component species is fragmentary (Danks 1981, 1999). Central to our understanding of terrestrial polar arthropods is knowledge about possible life-history adaptations to the harsh polar environment. Many of the typical life-history traits of polar arthropods (e.g., extended life span and reduced reproductive output) agree with predictions from adversity selected life-history strategies (Convey 1996). However, many of these traits must be viewed as plesiotypic (ancestral) characters, enabling successful colonization of the arctic environment, or consequences of ecological or physiological limita tions (Danks 1981; Norton 1994; Convey 1996). 4 Oribatid mites are usually among the most abundant and species-rich ar thropods in arctic soils (Behan 1978; Danks 1981), however, little information exists about their demography and life histories in cold regions. In the Ant arctic only one species, Alaskozetes antarcticus (Michael), has been studied in detail (Block and Convey 1995), whereas the holarctic Ameronothrus lineatus (Thorell 1871) is the only oribatid mite inhabiting arctic regions, for which detailed knowledge on life history and demography exists (S0vik et al. 2003; S0vik and Leinaas 2003a, b). The latter species is found in littoral habitats across a wide latitudinal gradient extending from warm-temperate to high arctic regions. This makes it a good model organism for studies of local adaptation, as population-specific differences in life history can be examined across a correspondingly wide environmental gradient. Warm-temperate coastal regions have a uniform climate with precipitation distributed evenly throughout the year. Growing seasons are long whereas winters are short and mild (average temperatures of 0-3 °C in December-February) (www.metof fice.gov.uk; www.dwd.de). In comparison, summers in the high Arctic are short (2-4 months) and cold with restricted time for reproduction and com pletion of life cycles. The winter is long with low soil temperatures (0 to -30°C) (Coulson et al. 1995, 2000), depending on air temperature and snow cover. Arctic habitats are generally arid because of low precipitation and high winds (Danks 1981, 1999). The present study attempts to elucidate possible local life-history adapta tions of A. lineatlls to the arctic environment by comparing arctic and tem perate populations. Additionally, the paper provides an overview of published research on the general biology of arctic populations of A. lineatus. Taxonomy and distribution Ameronothrus lineatus (Figure 1), first described from Svalbard as Eremaeus lineatus (type species), belongs to Ameronothridae Willmann 1931, which comprises species found in intertidal and terrestrial habitats in both hemi spheres (Schulte and Weigmann 1977). Ameronothrus Berlese 1896 is pre dominately northern. The 10 species (Gilyarov 1975; Schubart 1975; Weigmann and Schulte 1975) are mainly aquatic or semiaquatic, being dis tributed on arctic, temperate and subtropical coastlines (Schuster 1966, 1988; Schulte et al. 1975; Schulte and WPoigmann 1977). The latitudinal distribution of A. lineatus stretches from southern England to the high Arctic, covering almost 30° of latitude (Coli off 1984). In North America the equally wide distribution is shifted southwards into northern California (Schulte et al. 1975; Schulte 1978). No reports exist from the Canadian high Arctic (Danks 1981), probably due to limited sampling in those inaccessible regions. Thus, A. lineatus has so far been found in Iceland, the Faroe Islands, Greenland, Jan Mayen, Svalbard, Novaja Semlja, arctic Siberia, 5 Figure 1. Ameronothrus lineatlls. Lateral view of a female (from Colesbukta, Spitsbergen). Fennoscandia, Great Britain, Ireland, Germany, Canada, Alaska, and Cal ifornia (Hammer 1944; Strenzke 1955; Weigmann and Schulte 1975; Behan 1978; Danks 1981; Karppinen and Krivolutsky 1982; Colloff 1984; Coulson and Refseth 2004). It is the only ameronothrid reported from the high-arctic Sval bard (Coulson and Refseth 2004), where it has been sampled on Bear Island and along the west and north coast of Spitsbergen (Summerhayes and Elton 1923, 1928; Karppinen 1967; S0vik et al. 2003). The life-history studies referred to in the present work were carried out using specimens from Adventdalen (78°0'N 15°30'E) and Colesbukta (78°5'N 14°57'E) on West Spitsbergen. Life history Life-cycle stages Oribatid mites have six life-cycle stages: pre-larva, larva, proto-, deuto-, tri tonymph and adult. The pre-larva does not hatch from the egg (Norton 1994; Walter and Proctor 1999), and in Ameronothrus is seen as a layer of cuticle within the eggshell (Schubart 1975). The majority of oribatid species deposit eggs, but some retain the progeny until the larval stage (Iarviparity) (Norton 1994). This seems to be a plesiotypic trait of the genus Ameronothrus (Schubart 1970, 1975; Weigmann and Schulte 1975; Pugh and King 1986; Tilrem 1994; Biicking et al. 1998). Strictly speaking, A. lineatus is ovoviviparous as the larvae hatch from the eggs some hours after deposition (Haq et al. 1991; S0vik