DOCSLIB.ORG

Asellota, Asellidae)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Asellota, Asellidae) The Freshwater lsopods of the Genus Lirceus (Asellota, Asellidae) LESLIE HUBRICHT and J. G. MACKIN V Reprinted from "THE AMERICAN MIDLAND NATURALIST" Vol. 42, No. 2, pp. 334-349, September, 1949 Notre Dame, Ind. The Freshwater lsopods of the Genus Lirceus (Asellota, Asellidae) Leslie Hubricht 912 Main St., Danville, Virginia J. G. Mackin Texas A & M Research Foundation, Grande Isle, Louisiana In the genus Asellus we have, in the first and second pleopoda of the male, characters which can be relied upon to distinguish the species, but in Lirceus these appendages are so similar in different species that they are, with one exception, useless as a means of separation. This is not because the species of Lirceus are less distinct than Asellus, but requires that the animal as a whole be studied rather than a single appendage. To an experienced observer the various species are easily distinguished in the field by those subtile differences in form and color which are almost impossible to describe. Difficulties begin when one brings specimens into the laboratory and attempts to define the dif- ferences. The commonest cause of difficulty is depauperate specimens. Under adverse conditions the animals are stunted, the gnathopoda do not develop their processes, and the uropoda remain in juvenile form. When this depau- perization is extreme the collection cannot be determined, but must be as- sumed to belong to the species in the range of which it was found. The isopods discussed herein have, in the past, been treated under the generic name Mancasellus Harger, rather than the prior Lirceus of Rafinesque. Rafmesque's description, though very poor, is sufficient to determine the genus. Since only one species of asellid occurs in the vicinity of Lexington, Kentucky, the type locality, there is no doubt as to the identity of Rafinesque's species. AN EVALUATION OF THE CHARACTERS USED TO DISTINGUISH SPECIES IN LIRCEUS Because appendages and other structures of taxonomic value are so much better developed in males than in the females, determinations can more advan- tageously be made from them. Therefore, in the following discussion and in the descriptions the females have been ignored, and of the males only those well developed are used as a basis for description. General body form.—Young specimens about 'A inch long are about 3.5 times as long as broad. In some species they become proportionately broader as they grow older until they may be a little less than twice as long as broad, so that this is a useful character in fully developed specimens but useless with depauperates. Whether or not the body is contracted or relaxed affects these 334 1949 HUBRICHT ET AL.: FRESHWATER ISOPODS 335 proportions and it was found that they could be expressed better by the pleo- telson alone. Color.—The basic color pattern is quite similar in all the species. There is a median zone which may or may not be mottled, on each side of this is a wide lateral zone which is mottled with yellowish and in some species has a dark border on both sides giving the animal the appearance of having four longitudinal bands, and there is a usually lighter marginal zone. Although some of the species are rather distinctly colored the differences are difficult to describe and must be seen to be really understood. Head.—In some species the head is incised but in others it is entire; in still others both conditions occur with occasional intermediates. Antennae.—The differences in the antennae between species are so slight and the age differences so great that they are useless as taxonomic characters and have not been used in this paper. Mouth Parts.—There are no specific peculiarities in the mouth parts other than those pertaining to the mandibulary palp. Most species are without a palp but some have a three-jointed palp and in others the structure has only one joint. In L. hoppinae the palp may consist of three joints, two, or only one, or the entire structure may be absent. Gnathopoda.—In the gnathopoda one finds the best characters for the dif- erentiation of species, but the study of immature or dwarfed specimens may be most confusing. The effects of depauperization are most noticeable in modification of the propodi and these structures are most subject to aberrations. In depauperate specimens the processes of the propodi do not develop fully, or in extreme cases not at all, on the other hand, in animals of normal size one or more processes may become over-developed. This is particularly true of the proximal process—when it becomes enlarged it usually produces a reduc- tion in the distal process. These aberrations are apparently of somatic origin as they rarely affect both gnathopoda. The palmar margin is usually armed with three processes, the proximal, median, and distal, and comparison of the relative development of these has proved most valuable in delimiting species. Pleopoda.—The first and second pleopoda of the male which have been found so useful in separation of species of Asellus are of doubtful, value in Lirceus. The tip of the endopodite of the second peopoda which in Asellus differs so completely from species to species, in Lirceus differs only by slight variations in a single basic pattern. The tip is usually bent forward but some- times it is twisted inwards which gives it a quite different aspect, but the differ- ence is more apparent than real. Uropoda.—The uropoda vary considerably with age, also they are easily lost and the regenerated ones are never as large as the originals, and in some species dimorphism occurs. However, the uropoda of mature specimens con- tribute important characters for delimiting species. 336 THE AMERICAN MIDLAND NATURALIST 42 (2) Genus LIRCEUS Rafinesque 1820. Lirceus Rafinesque, Annals of Nature, 1: 7. 1874. Asellopsis Harger, Amer. Jour. Sci. & Arts, III, 7: 601-602. (non) Asellopsis Brady at Robertson, Ann. & Mag. Nat. Hist., IV, 12: 137-138. 1873. 1876. Mancasellus Harger, Amer. Jour. Sci. & Arts, III, 11: 304-305. Description.—With the characters of the family Asellidae. Head laterally expanded and flattened and with a well-defined median anterior keel projecting forward between the antennae. Epimera broad, coalesced with their segments. Mandible without a palp, with a three-jointed palp, or of various intermediate conditions. Peni set close together. Suture between the basal and distal seg- ments of the exopodite of the third pleopod very oblique, the distal segment triangular or half-moon shaped. Type species.—Lirceus fontinalis Rafinesque. Distribution.—Southern Canada and eastern United States west to the Great Plains. Remarks.—The genus Lirceus probably consisted originally of a single entity which under the influence of geographical and ecological isolation has evolved into a number of distinct species which, with a few exceptions, replace each other geographically. This divergence is without pattern or geographical trends. Species inhabiting adjacent areas are apt to differ most. Unlike Asellus, in which the majority of the species are subterranean, Lirceus has produced no true cave forms. It is rarely found in caves, and in only one instance is it known to have become modified by cave life. KEY TO THE SPECIES I. Mandible with a palp 2 Mandible without a palp 7 2. Mandibular palp of a stub or one or two joints 3 Mandibular palp with three joints 5 3. Pleotelson distinctly broader than long L. hoppinae ozarkensis Pleotelson only very slightly wider than long 4 4. Median propodal process acutely pointed, distinctly longer and more strongly developed than the proximal process; distal process present, small L. fontinalit Median process blunt, and little, if any longer than the proximal process; distal process absent L. bidentatus 5. Both median and distal propodal processes bicuspid_ L. bicuspidatus Neither median nor distal propodal processes bicuspid 6 6. Pleotelson wider than long L. hoppinae hoppinae Pleotelson longer than broad L. alabamae 7. Median and distal propodal processes absent L. brachyurus Median process and usually also the distal process of the propodi present 8 8. Uropodal sinuses of the pleotelson acutely incised L. trilobus Uropodal sinuses of the pleotelson not acutely incised, represented by rounded con- cavities or absent 9 9. Endopodite of the uropoda equal to or longer than the basal segment 10 Endopodite distinctly shorter than the basal segment 15 10. Proximal process of the propodi as large as or larger than the median process 11 Proximal process distinctly smaller than the median process 12 1949 HUBRICHT ET AL.: FRESHWATER ISOPODS 337 11. Proximal and median processes of the propodi crowded close together, the distance between them being little if any greater than the width of the proximal process L. garmani Proximal and median processes widely separated, the distance between them being sensibly greater than the width of the proximal process L. hargeri 12. Uropoda flattened 13 Uropoda cylindric in form 1,. lineatus 13. Median process of the propodi bicuspid or squarely truncate terminally L. richardsonae Median process either rounded terminally or acutely pointed 14 14. Uropodal sinuses of the pleotelson weakly developed; tip of the median propodal process acutely pointed; pleotelson only slightly broader than long L. fontinalis Uropodal sinuses of the pleotelson moderately well developed, the pleotelson dis- tinctly broader than long; median process of the propodi rounded truncate ter- minally L. hoppinae ouachitaensis 15. Pleotelson longer than broad 16 Pleotelson as broad as long or very distinctly broader 17 16. Proximal process of the propodi large, well developed, larger than the median process L. megapodus Proximal process absent, represented by a blunt spine at the angle of the palm L louisianae 17. Uropoda flattened L. fontinalis Uropoda cylindric L. lineatus As a further aid in the determination of specimens the species are arranged geographically from east to west and from north to south.
Load more

Recommended publications
  • Species of Greatest Conservation Need
    APPENDIX A. VIRGINIA SPECIES OF GREATEST CONSERVATION NEED Taxa Common Scientific Name Tier Cons. Opp. Habitat Descriptive Habitat Notes Name Ranking Amphibians Barking Hyla gratiosa II a Forest Forests near or within The Virginia Fish and Wildlife Information System indicates treefrog shallow wetlands the loss suitable wetlands constitute the greatest threats to this species. DGIF recommends working to maintain or restore forested buffers surrounding occupied wetlands. These needs are consistent with action plan priorities to conserve and restore wetland habitats and associated buffers. Recently discovered populations within its known range, may indicate this species is more abundant than previously believed. An in-depth investigation into its status may warrant delisting. This species will be prioritized as Tier 2a. Amphibians Blue Ridge Desmognathus IV c Forest High elevation seeps, This species' distribution is very limited. Other than limiting dusky orestes streams, wet rock faces, logging activity in the occupied areas, no conservation salamander and riparian forests actions have been identified. Unless other threats or actions are identified, this species will be listed as Tier 4c. Amphibians Blue Ridge Eurycea III a Wetland Mountain streams and The needs of this species are consistent with priorities for two-lined wilderae adjacent riparian areas maintaining and enhancing riparian forests and aquatic salamander with mixed hardwood or habitats. This species will be listed as Tier 3a. spruce-fir forests up to 6000 feet. Amphibians Carpenter Lithobates III a Wetland Freshwater wetlands with The needs of this species are consistent with action plan frog virgatipes sphagnum moss priorities to preserve and restore aquatic and wetland habitats and water quality.
    [Show full text]
  • 1994 IUCN Red List of Threatened Animals
    The lUCN Species Survival Commission 1994 lUCN Red List of Threatened Animals Compiled by the World Conservation Monitoring Centre PADU - MGs COPY DO NOT REMOVE lUCN The World Conservation Union lo-^2^ 1994 lUCN Red List of Threatened Animals lUCN WORLD CONSERVATION Tile World Conservation Union species susvival commission monitoring centre WWF i Suftanate of Oman 1NYZ5 TTieWlLDUFE CONSERVATION SOCIET'' PEOPLE'S TRISr BirdLife 9h: KX ENIUNGMEDSPEaES INTERNATIONAL fdreningen Chicago Zoulog k.J SnuicTy lUCN - The World Conservation Union lUCN - The World Conservation Union brings together States, government agencies and a diverse range of non-governmental organisations in a unique world partnership: some 770 members in all, spread across 123 countries. - As a union, I UCN exists to serve its members to represent their views on the world stage and to provide them with the concepts, strategies and technical support they need to achieve their goals. Through its six Commissions, lUCN draws together over 5000 expert volunteers in project teams and action groups. A central secretariat coordinates the lUCN Programme and leads initiatives on the conservation and sustainable use of the world's biological diversity and the management of habitats and natural resources, as well as providing a range of services. The Union has helped many countries to prepare National Conservation Strategies, and demonstrates the application of its knowledge through the field projects it supervises. Operations are increasingly decentralised and are carried forward by an expanding network of regional and country offices, located principally in developing countries. I UCN - The World Conservation Union seeks above all to work with its members to achieve development that is sustainable and that provides a lasting Improvement in the quality of life for people all over the world.
    [Show full text]
  • •Not! Ptdition, X:213-230
    78 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY Carman, S. Knjyer, H. 1889. Cave Animal j from South we item Missouri. Bulle­ 1838. Gronlands Amphipoder. Kongelige danske viden* tin of the Museum of Comparative Zoology, skabernes Selskabbiologiske Skrifter, 7:229-326. 17(6):225-239. Latreille, P. A. Geoffrey Saint-Hilaire, E. L. 1803. Histoire naturelle, ginirale et particuliire, des 1764. Histoire abrigie dts Insectes qui se troitvcnt aux Cruslacis et dts Insectes, 6:1-391. Paris.* environs de Paris. Pari*.* Leonard, A. B,, and L. H. Ponder Gould, A. A, 1949. Crustacea of Eastern Kansas. Transactions of the 1841. Report on the Invertebrate Animals of Massachu­ Kansas Academy of Science, 52:168-204. setts. Cambridge: Massachusetts. Levi, H. W. Gruner, H. £. 1949. Two New Species of Cave Isopods from Pennsyl­ 1965. Die Tierwelt Deutschlands. Krebstiere oder Crus­ vania. Notulae Naturae, 220:1-fi. tacea. V, Isopoda. 53. Teil, 2 Lf. Jena. Linnaeus, C. Hansen, H. J. 1758. Systema Naturae. 10th Edition, 824 pages* 1888. Oversigt over det vestlige Gronlands Fauna. Mac Lin, J. G. Videnskabelige Meddeletier jra dansk Naturhis- 1940. A Key to the Oklahoma Species of the Family torisk Forening Kjobenhacn, 1887:177-198. Asellidae. Proceedings of the Oklahoma Academy Harford, W. G. W. of Science, 20:17-18. 1877. Description of a New Genus and Three New Spe­ Mackin, J. G, and L. Hubricht cies of Sessile Eyed Crustacea. Proceedings of the 1938. Records of Distribution of Species of Isopods in California Academy of Science, 7:53-55. Central and Southern United States, with Descrip­ Harger, O. tions of Four New Species of Mancasellus and 1874.
    [Show full text]
  • And Community Structure
    studet reasol food , and ir comp fauna and S the re and I classr other unde paras Th simp SpeciesInteractions this r inter and CommunityStructure short from Ti Questions concerning the nature and importance of species interac- vari< tions have become increasingly controversial. In the mid-1960sit was tive thought that interspecific competition was the major organizing factor ond in many communities. Through the pioneering work of the late Robert and MacArthur and his students,many aspectsof the structure and dynam- com ics of bird communities seemedbest explained by competitive interac- ied r tions, which could be describedin a generalway by the Lotka-Volterra spec competition equations. This work, or at least its generality, has been ofn challengedon three levels. First, there is the question of how important species interactions are in general and whether the interactions are competitive, parasitic, predatory, or mutualistic. For example, Connell whi (1975)noted that a significantfraction of, but by no means all, commu- nities are physically rather than biotically controlled. In addition, there As has been a tendency in the last few years to concentrate on single- dyn species demography. While interactions between species can still be the considered in the guise of age-specificfecundity and mortality effects, (va the emphasisis away from a coevolutionary perspective and toward a hos individualistic concept of communities. the Second, the question of which type of interaction is most important sor in structuring a particular community is very much open. Many ecol- tha ogists have pointed out that the birds studied by MacArthur and his wit SPECIESINTERACTIONS 97 studentswere at or near the top of the food chain.
    [Show full text]
  • Endemic Flora and Fauna of Arkansas Henry W
    Journal of the Arkansas Academy of Science Volume 36 Article 17 1982 Endemic Flora and Fauna of Arkansas Henry W. Robison Southern Arkansas University Kenneth L. Smith Arkansas Natural Heritage Commission Follow this and additional works at: http://scholarworks.uark.edu/jaas Part of the Terrestrial and Aquatic Ecology Commons Recommended Citation Robison, Henry W. and Smith, Kenneth L. (1982) "Endemic Flora and Fauna of Arkansas," Journal of the Arkansas Academy of Science: Vol. 36 , Article 17. Available at: http://scholarworks.uark.edu/jaas/vol36/iss1/17 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact [email protected], [email protected]. Journal of the Arkansas Academy of Science, Vol. 36 [1982], Art. 17 THE ENDEMIC FLORA AND FAUNA OF ARKANSAS HENRY W. ROBISON Department of Biological Sciences Southern Arkansas University Magnolia, Arkansas 71753 KENNETH L.SMITH Arkansas Natural Heritage Commission Suite 500, Continental Building Little Rock, Arkansas 72201 ABSTRACT Arkansas has an amazing diversity of plants and animals contained within its political boundaries. Forty-seven taxa are reported as Arkansas endemics, including seven plants, thirteen crustaceans (two amphipods, three isopods, eight crayfishes), nine insects (one mayfly, one caddisfly, three stoneflies, four beetles), ten snails, six fishes, and two salamanders.
    [Show full text]
  • Annotated Checklist of the Isopoda (Subphylum Crustacea: Class Malacostraca) of Arkansas and Oklahoma, with Emphasis Upon Subterranean Habitats
    1 Annotated Checklist of the Isopoda (Subphylum Crustacea: Class Malacostraca) of Arkansas and Oklahoma, with Emphasis Upon Subterranean Habitats G. O. Graening Department of Biological Sciences, California State University at Sacramento, Sacramento, CA 95819 Michael E. Slay Arkansas Field Office, The Nature Conservancy, 601 North University Avenue, Little Rock, AR 72205 Danté B. Fenolio Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33124 Henry W. Robison Department of Biology, Southern Arkansas University, Magnolia, AR 71754 All known records of isopod crustaceans (Order Isopoda) in the states of Arkansas and Oklahoma are summarized, including new state, county, and site records. This updated checklist recognizes 47 taxa in 9 families: 2 taxa in Armadillidiidae; 1 in Armadillidae; 30 in Asellidae; 1 in Cylisticidae; 1 in Ligiidae; 1 in Oniscidae; 4 in Porcellionidae; 1 in Trachelipodidae; and 6 in Trichoniscidae. This faunal inventory includes 17 taxa that are subterranean obligates (troglobites or stygobites), and 14 taxa that are endemic to this geographical region. Current distributions and conservation statuses are summarized, and new rarity rankings are suggested. © 2007 Oklahoma Academy of Science INTRODUCTION these two states are closely associated with subterranean habitats, and those species This study assembles the first checklist restricted to hypogean habitats are typically of the entire Order Isopoda (Subphylum troglomorphic (i.e., exhibiting loss of pig- Crustacea: Class Malacostraca)
    [Show full text]
  • Lee County Cave Isopod Lirceus Usdagalun
    U.S. Fish & Wildlife Service Lee County Cave Isopod Lirceus usdagalun Description and integrity of the underground The Lee County cave isopod is an environment is completely dependent obligate cave water dwelling organism on the management of the surface documented in only four caves in environment and the activities that Lee County, Virginia. Three of the occur there. caves are connected by groundwater, resulting in a single cave system. The What you can do to help fourth cave is located approximately If you reside on property that borders six miles northeast of that system, but a stream or other waterway, avoid as a result of groundwater pollution using chemicals or fertilizers. To the isopod no longer occurs there. This help control erosion and reduce L. Koch isopod lacks a hard body cover, eyes, runoff, maintain a buffer of natural References and pigmentation and possesses vegetation along waterbodies and Reynolds, R. and J.R. Holsinger. seven pairs of leg-like appendages. sinkholes. Never place anything into 1995. Lee County cave isopod. Its total length is up to 0.3 inches. sinkholes. Install fencing to prevent Page 56 in K. Terwilliger, J.R. Tate, livestock from entering streams, this and S.L. Woodward, eds. A guide to Life History will reduce siltation and input of endangered and threatened species This freshwater crustacean is found on waste products. Properly dispose of in Virginia. McDonald and the surfaces of small rocks and gravel household wastes, including used Woodward Publishing Company, in cave streams or similar habitat at motor oil, at recycling facilities and Blacksburg, Virginia.
    [Show full text]
  • The Subterranean Fauna of the Arbuckle Mountains Ecoregion of Oklahoma, USA
    Graening, Fenolio & Harris The subterranean fauna of the Arbuckle Mountains Ecoregion of Oklahoma, USA Gary O. Graening1, Danté B. Fenolio2 & Keith A. Harris3 1Department of Biological Sciences, California State University, Sacramento, 6000 J Street, Sacramento, CA 95819-6077, USA [email protected] (corresponding author) 2Department of Conservation and Research, San Antonio Zoo, 3903 N. St. Mary’s Street, San Antonio, TX 78212, USA [email protected] 3Tulsa Regional Oklahoma Grotto, National Speleological Society, 2813 Cave Avenue, Huntsville, AL 35810, USA [email protected] Key Words: Allocrangonyx pellucidus, amphipod, Arbuckle Mountains ecoregion, Asellidae, biodiversity, Caecidotea acuticarpa, Chaetaspis, Crosbyella, Desmoniella curta, Etheostoma microperca, isopod, Macrosternodesmidae, Miktoniscus oklahomensis, Oklahoma, Phalangodidae, Sphaeriodesmidae, stygobiotic, Stygobromus alabamensis, range extension, new record, Trichoniscidae, troglobiotic. The Arbuckle Mountain Uplift, and the Arbuckle PlainsSPBN to a lesser extent, hosts an impressive density of caves in karstified limestone formations (e.g., West Spring Creek and Kindblade) of the Ordovician Period. These caves serve as karst windows into the extremely deep and productive Arbuckle-Simpson Aquifer (Graening et al. 2011). The fauna found within subterranean habitats within the Arbuckle Mountains Ecoregion of Oklahoma (Carter, Coal, Johnston, Murray, and Pontotoc counties) were investigated as part of a larger bioinventory program (Graening et al. 2008; Graening et al. 2011). Previous studies of subterranean habitats in or near this ecoregion include Creaser and Ortenberger (1933), Mackin (1935), Mackin and Hubricht (1940), Hall (1956), Chamberlin and Hoffman (1958), Harrel (1960, 1963), Vandel (1965, 1977), Black (1971, 1973, 1974), Holsinger (1971, 1989), Fleming (1972), McKinley et al. (1972), Reisen (1975), Matthews et al. (1983), Vaughn (1996), Gaskin and Bass (2000), Lewis (2002), The Nature Conservancy (2004), Graening et al.
    [Show full text]
  • Section 8. Appendices
    Section 8. Appendices Appendix 1.1 — Acronyms Terminology AWAP – Arkansas Wildlife Action Plan BMP – Best Management Practice CWCS — Comprehensive Wildlife Conservation Strategy EO — Element Occurrence GIS — Geographic Information Systems SGCN — Species of Greatest Conservation Need LIP — Landowner Incentive Program MOA — Memorandum of Agreement ACWCS — Arkansas Comprehensive Wildlife Conservation Strategy SWG — State Wildlife Grant LTA — Land Type Association WNS — White-nose Syndrome Organizations ADEQ — Arkansas Department of Environmental Quality AGFC — Arkansas Game and Fish Commission AHTD — Arkansas Highway and Transportation Department ANHC — Arkansas Natural Heritage Commission ASU — Arkansas State University ATU — Arkansas Technical University FWS — Fish and Wildlife Service HSU — Henderson State University NRCS — Natural Resources Conservation Service SAU — Southern Arkansas University TNC — The Nature Conservancy UA — University of Arkansas (Fayetteville) UA/Ft. Smith — University of Arkansas at Fort Smith UALR — University of Arkansas at Little Rock UAM — University of Arkansas at Monticello UCA — University of Central Arkansas USFS — United States Forest Service 1581 Appendix 2.1. List of Species of Greatest Conservation Need by Priority Score. List of species of greatest conservation need ranked by Species Priority Score. A higher score implies a greater need for conservation concern and actions. Priority Common Name Scientific Name Taxa Association Score 100 Curtis Pearlymussel Epioblasma florentina curtisii Mussel 100
    [Show full text]
  • Aquatic Invertebrate Report
    Aquatic Invertebrate Report Caecidotea fonticulus Class: Malacostraca Order: Isopoda Family: Asellidae Priority Score: 23 out of 100 Population Trend: Unknown G Rank: G? — Uncertain global ranking S Rank: S1 — Critically imperiled in Arkansas Distribution Ecoregions where the species occurs: Ozark Highlands Mississippi Valley Loess Plains Boston Mountains Mississippi Alluvial Plain Arkansas Valley South Central Plains Ouachita Mountains Element Occurrence Records Taxa Association Team and Reviewers ANHC Mr. Michael Warriner, AGFC Mr. Brian Wagner Caecidotea fonticulus Page 713 isopod Aquatic Invertebrate Report Ecobasins where the species occurs Ecobasins Ouachita Mountains - Ouachita River Habitats Weight Natural Groundwater: Headwater - Small Data Gap Natural Seep: Headwater - Small Data Gap Natural Spring Run: Headwater - Small Obligate Problems Faced Threat: Habitat destruction or conversion Source: Forestry activities Threat: Toxins/contaminants Source: Municipal/Industrial point source Data Gaps/Research Needs Need to obtain baseline information on distribution and population status. Conservation Actions Importance Category More data is needed to determine conservation actions. Medium Data Gap Monitoring Strategies Surveys to locate additional populations and protection of stream habitats Comments An Arkansas endemic isopod known only from Abernathy Spring in Polk County (Lewis 1983). Caecidotea fonticulus Page 714 isopod Aquatic Invertebrate Report Pyrgulopsis ozarkensis Class: Gastropoda Order: Neotaenioglossa Family: Hydrobiidae Priority Score: 80 out of 100 Population Trend: Unknown G Rank: G1 — Critically imperiled species S Rank: S1? — Critically imperiled in Arkansas (inexact numeric rank) Distribution Ecoregions where the species occurs: Ozark Highlands Mississippi Valley Loess Plains Boston Mountains Mississippi Alluvial Plain Arkansas Valley South Central Plains Ouachita Mountains Element Occurrence Records Taxa Association Team and Reviewers ANHC Mr.
    [Show full text]
  • Caecidotea Burkensis, New Species, a Unique
    Salisa L. Lewis, Julian J. Lewis and William Orndorff. Caecidotea burkensis, new species, a unique subterranean isopod from Burke’s Garden, with a synthesis of the biogeography and evolution of southwestern Virginia asellids. Journal of Cave and Karst Studies, v. 83, no. 2, p. 78-87. DOI:10.4311/2020LSC0126 CAECIDOTEA BURKENSIS, NEW SPECIES, A UNIQUE SUBTERRANEAN ISOPOD FROM BURKE’S GARDEN, WITH A SYNTHESIS OF THE BIOGEOGRAPHY AND EVOLUTION OF SOUTHWESTERN VIRGINIA ASELLIDS Salisa L. Lewis1, Julian J. Lewis2,C and William Orndorff3 Abstract Caecidotea burkensis, a new species of subterranean asellid isopod, is described and illustrated from material collect- ed from Lawson Cave, in Burke’s Garden, Tazewell County, Virginia. The type-locality in Burke’s Garden is located within the highest mountain basin in the southern Appalachians. Burke’s Garden is a unique, geologically isolated area encompassing one of the headwater streams of the New River basin. Phylogenetically, the isopod is a member of the forbesi Group, a clade comprised primarily of epigean species. The complex mountain valleys and coves of south- western Virginia are an area of intense speciation among asellids that have produced a bizarre array of cavernicolous species belonging to groups of otherwise epigean isopods. In addition to a few subterranean species of the Caecidotea cannula and stygia Groups, the Lirceus hargeri Group possesses over a dozen species endemic to caves and springs in the region, mostly only now in the process of being discovered and described. With so much species richness, syn- topy of two, or even three, asellid species is commonplace in caves and springs in southwestern Virginia.
    [Show full text]
  • The Scutocoxifera Tax. Nov. and the Information Content of Nuclear Ssu Rdna Sequences for Reconstruction of Isopod Phylogeny (Peracarida: Isopoda)
    JOURNAL OF CRUSTACEAN BIOLOGY, 22(2): 217–234, 2002 THE SCUTOCOXIFERA TAX. NOV. AND THE INFORMATION CONTENT OF NUCLEAR SSU RDNA SEQUENCES FOR RECONSTRUCTION OF ISOPOD PHYLOGENY (PERACARIDA: ISOPODA) Hermann Dreyer and Johann-Wolfgang Wägele Lehrstuhl Spezielle Zoologie, Fakultät für Biologie, Ruhr-Universität Bochum, Universitätstr. 150, 44780 Bochum, Germany (corresponding author (JWW) e-mail: [email protected]) ABSTRACT The nuclear ssu rRNA gene of several isopods (Crustacea, Peracarida) was sequenced to study its phylogenetic information content. Several areas had to be cut out of the alignment of 31 isopod se- quences and selected outgroup arthropod sequences due to the lack of alignable patterns. The final alignment had 2,533 positions and 43 sequences. The length of the isopod nuclear ssu rRNA genes varies between 2,098 and 3,402 bp. In some clades the gene length increases; in others like the cy- mothoids and bopyrids, long deletions occur. Some insertions are specific for major groups (e.g., amphipods, isopods). Most elongation areas evolve rapidly and are not alignable among higher taxa. Information content is visualized with spectra of supporting positions. Only a few groups are unambiguously supported with a signal distinctly higher than background noise. The results of maximum parsimony analyses are congruent with major aspects of earlier hypotheses on isopod phylogeny. Some contradictions are discussed. The latter are mainly based on a lack of reliable in- formation. A major monophyletic group found in the molecular phylogenies and also supported by distinct morphological characters is named Scutocoxifera tax. nov., composed of the Oniscidea, Valvifera, Sphaeromatidea, Anthuridea, and Cymothoida.
    [Show full text]