MOLLUSKS OF UTAH

A SIMPLE GUIDE

White-lip Dagger ©Rick Fridell

UTAH DIVISION WILDLIFE RESOURCES

2017

ii

TABLE OF CONTENTS

Acknowledgements…………………………………….......v

Introduction……………………………………………….vi

What to do if you find Mollusks…………………..........viii

Gastropods…………………………………….……….…..1

Freshwater snails………………………….…………….....2

Amnicolidae…………………………………….….2

Cochliopidae……………………………………….4

Hydrobiidae……………………………………......5

Lithoglyphidae………………………….………...12

Valvatidae……………………………….…….......13

Lymnaeidae…………………………….…………14

Physidae……………………………….…………..21

Planorbidae………………………….……………25

Viviparidae………………………….…………….31

Thiaridae…………………………….……………32

Tateidae…………………………….…………… 33

iii

Terrestrial snails…………………………….…….………34

Succineidae………………………….………..…...34

Cochlicopidae……………………….…………….37

Pupillidae…………………………….……………38

Vallonidae…………………………….…………...41

Vertiginidae…………………………….…………43

Punctidae……………………………….…………47

Discidae……………………………….……...…...48

Helicodiscidae…………………….………………49

Oreohelicidae………………………………….….50

Gastrodontidae…………………………………...54

Euconulidae………………………………………55

Oxychilidae……………………………………….56

Pristilomatidae…………………………………...58

Vitrinidae…………………………………………60

Thysanophoridae………………………………...61

Subulinidae………………………….……………62

Helicidae………………………………………….63

iv

Polygyridae………………………………………64

Agriolimacidae…………………………………..65

Limacidae………………………………………..66

Bivalves …………………………………………………..67

Freshwater Mussels……………………………………...68

Margaratiferidae………………………………...69

Unionidae………………………………………...70

Dreissenidae……………………………………...72

Freshwater Clams………………………………….……..73

Sphaeriidae……………………………….………73

Corbiculidae……………………………………...79

Glossary …………………………………………………..80

References…………………………………………………91

v

ACKNOWLEDGMENTS

We would like to thank several folks for their contribution to this guide: Lisa Graham, Dr. Robert Hershler, Peter Hovingh, Sarra Jones, Pam Martin, George Oliver, Mark Ports, Dr. David Richards, Dr. Donald W. Sada, and Sarah Seegert. We spent countless hours searching the internet, other states’ guides, and published literature to compile as much known information as available into this guide. We credited the source of pictures and information, as much as possible and as available.

We hope you find this guide a useful tool in identification of the mollusk species in Utah.

Krissy Wilson Assistant Wildlife Program Chief, Salt Lake Office krissywilson@utah.gov 801-538-4756 Kevin Wheeler Native Aquatic Biologist, Washington County Field Office kevinwheeler@utah.gov 435-879-8694 Erin Bertram Native Aquatic Biologist, Salt Lake Office ebertram@utah.gov 801-538-4828

vi

INTRODUCTION

Utah’s mollusks are a unique and diverse group of animals that that occupy both terrestrial and aquatic habitats in Utah. These species provide vital ecosystem functions in the habitats they occupy, with some evolving highly specialized traits and occupying only a narrow range of habitat conditions. Utah’s snails play an important ecological role as primary consumers and detritivores in the terrestrial or aquatic habitat they occupy, while mussels and clams may contribute greatly to water quality through their filtering activities. They then convert these materials into forms of usable energy for other species that consume mollusks such as insects, fish, waterfowl, and many mammals. Mollusks are part of Utah’s wildlife that generally go unnoticed. This is partially because most are so small that most people overlook them. Little is understood about mollusk identification and life history, not only by the public, but also by wildlife professionals. Very few studies have been conducted on Utah mollusks, and the most recent comprehensive publication was written over 80 years ago (Chamberlain & Jones 1929). Many mollusks are difficult to identify in the field, and may require thorough examination to identify correctly. An excellent example is the small springsnail (genus Pyrgulopsis), a group of snails that are closely related, but have evolved into different species because of their isolated habitats. Most Utah springsnails are distinguished only by examining the male reproductive organs. Mollusk taxonomy (the naming and grouping of mollusks to a specific taxon) is confusing. Historically, mollusks were grouped together with those of similar shell shape (morphology). Recently, however, genetic analysis has revealed that there is great plasticity in shell morphology based on habitat and functionality, not only relatedness. Mollusks also show a great amount of convergent evolution, that is, species that are not closely related evolve similar traits, including shell shapes, to fill similar habitat niches.

vii

This leads to species that appear similar, but are not closely related. Recent (and ongoing) genetic studies have therefore re-assigned many species to different or newly recognized families, and there have been many lumps (combining of species previously recognized as distinct into one species) and splits (separation of distinct populations of a species as distinct species of their own). Because there is little agreement on nomenclature (names, both common and genus with species) for mollusks, this guide follows Johnson et al. (2013), which provides standardized names for all freshwater snails of the United States and Canada. Mollusks that are found in Utah can be easily divided into two groups: bivalves (Class Bivalvia), consisting of mussels and clams, and gastropods (Class Gastropoda), consisting of snails and slugs. Gastropods are commonly separated into freshwater snails and terrestrial snails (including slugs), although there are multiple evolutionary lines within both groups, so this grouping is not based on genetic relatedness. Also, the assignment of some mollusks as “terrestrial” is somewhat misleading, as all mollusks require moisture to survive, and many species in this group are commonly found in wetlands. Utah species are taxonomically grouped into currently recognized families in this guide. Photographs or illustrations of many species are shown, although these resources were not found for some of the species. The purpose of this guide is to provide information for anyone interested in learning basic identification of Utah’s mollusks at least to family level and then be able to document the distribution of mollusks throughout Utah.

viii

WHAT TO DO IF YOU FIND MOLLUSKS BASIC STEPS AND GUIDELINES

1. Don’t destroy mollusks or their habitats. Walking around

in water bodies crushes and kills the mollusks. Turning surface cover (rocks, logs) and failing to replace the cover objects as they were dries out and otherwise destroys the moist, critical microhabitats beneath the cover. Always replace cover objects as they were, and be sure to replace them gently and carefully so that you don’t crush the snails and other organisms that live under them. Never displace or roll rocks down hillsides. Never leave turned cover (logs, rocks, boards, trash) over-turned or up-turned; replace cover objects as they were (even trash such as cardboard).

2. If you find live mollusks—especially live native mussels (floaters or pearlshells), or other mollusks as well—don’t immediately collect them.

3. Put native mussels (floaters or pearlshells) back in the substrate exactly as you found them. If you put them back upside down, they’ll die. Some mollusks are very long-lived and take a very long time to reach sexual maturity. Floaters, for example, live for decades; pearlshells live well over a hundred years.

4. If you find live mollusks, you usually can find their dead remains (shells). Exceptions include slugs and some of the small aquatic species, such as springsnails and ancylids.

5. Look for empty shells (snails) or valves (bivalves), and collect a few of these instead. Raccoons and muskrats are extremely effective predators of mussels and leave the empty valves along the banks of water bodies. Where there are live snails, there are almost always some or many shells. Shells of aquatic snails often float and/or are washed up on the shores of the water body. Exceptions include many of the small aquatic species, such as springsnails and ancylids. Shells of terrestrial snails can be found by carefully scraping through duff (leaf litter) or by looking under

ix

surface cover objects. Be aware that snails (including many aquatic species and most terrestrial species) aestivate. Aestivating terrestrial species may appear to be dead even though they are alive. If they are “stuck” (attached) to anything, they’re aestivating. If they have a dry, clear or opaque (whitish) membrane over the aperture (opening), they’re aestivating. Leave live, aestivating or non-aestivating terrestrial snails alone. Instead, look for dead, empty, often weathered shells, and collect a few of these. We don’t need 10 or 20 or 100 shells of the same kind; one or two will do. If possible put specimens in rigid containers, such as vials, so that the shells won’t risk being broken or crushed. A plastic bag containing crushed shell fragments is worthless.

6. If you can’t find any dead, empty shells or valves, photograph live ones, and put them back as you found them and where you found them. (See comment 2 above concerning mussels.

7. If you collect dead shells or photograph live mollusks, or even take notes about finding them, record the locality as precisely as possible (UTM coordinates if possible), a verbal description of the locality, the date, and anyone else, in addition to yourself, who also was there.

8. Send dead specimens or photographs, with data (location, date, your name), to the NAS Program, SLO. Contact Krissy Wilson, 801-538-4756 or Erin Bertram 801-538-4828.

If the dead, empty shells or the photographs are—or appear to be—species of interest or species of conservational concern, we’ll let you know what the next step(s) should be.

1

GASTROPODS Kingdom: Animalia Phylum: Mollusca Class: Gastropoda Gastropods are the largest group of mollusks that include snails and slugs. Most have a single spiral shell (which may be flattened or reduced), whereas, slugs have no shell. There are many types of gastropods: marine, freshwater, or terrestrial. Aquatic gastropods have gills and terrestrial snails breathe air with simple lungs. Depending on the species, gastropods may reproduce sexually or asexually. Gastropods have a muscular “foot” for moving and burrowing, distinct heads with tentacles, eyes, and mouths containing teeth like radula for scraping algae. In Utah, this group includes 11 families of freshwater snails (including three families that are introduced) and 20 families of terrestrial snails (including four introduced families).

Roy Averill-Murray

2

FRESHWATER SNAILS All aquatic snails in Utah have shells. Most use gills, but some need to surface to breathe. Most species are dextral (opening on the right), with the Physidae family being the exception. Phylum: Mollusca Class: Gastropoda

Family: Amnicolidae These are referred to as amnicolas and duskysnails. These are small snails with an operculum. These species can be fairly tolerant to warmer waters and low oxygen. Populations are typically found in lentic environments, sometimes in slow-moving rivers, and on woody debris. Mud Amnicola Amnicola limosus

• Shell small, 3.5-4.1 mm • 4 rounded whorls, blunt spire • Oval aperture with black

operculum

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Amnicola_limosa.htm

3

Rocky Mountain Duskysnail Colligyrus greggi • Shell small, 1.7-3.3 mm • Shell clear to white with 3.75-4.5 whorls • Well-developed shoulder • Ovate or circular aperture • Region: N

4

Phylum: Mollusca Class: Gastropoda

Family: Cochliopidae These snails are called tryonias. They are small snails with an operculum that live in rivers or brackish waters. The single Utah representative of this family has a longer shell and more whorls than similar species of this family. Desert Tryonia Tryonia porrecta

• Long shell (10 mm) with 7-8 whorls

• Shell often has ridges or ribs

• Occurs in springs and spring outflows

• Found in Fish Springs of Juab county, Tooele, and Utah counties

• Region: C

5

Phylum: Mollusca Class: Gastropoda

Family: Hydrobiidae

Hyrdobiidae is a very large family consisting of over 100 genera. These are springsnails that are very small (up to 4mm in height), dextral, usually dark in color, with coiled shells, and round operculae. Most species have 4 whorls. They are found in most freshwater habitat types. Longitudinal Gland Pyrg Pyrgulopsis anguina

• 2-3.5 mm long, 3-5 whorls • Sub-globose shell • Endemic to springs of Lake Creek • Region: S

Hershler 1998

6

Smooth Glenwood Pyrg Pyrgulopsis chamberlini

• 2.3-4.3 mm long, 4.5-6 whorls • Well-developed shoulders • Ovate shell and aperture • Occurs in same habitats with

Carinate Glenwood Pyrg • Region: S Hershler 1998

Desert Springsnail Pyrgulopsis deserta

• 1.2-2.5 mm long, 3.5-4.25 whorls • Globose shell • Shouldered • Aperture angled above, may be

slightly separated from body whorl • Only found in Virgin Drainage

Otter Creek Pyrg Pyrgulopsis fusca • 2.5-4.5 mm, 4.25-5.25 whorls • Ovate shell • Shoulders • May have faint spiral striae • Aperture often slightly disjunct

from body whorl • Aperture ovate • Only found in springs adjacent to

Otter Creek and tributaries Hershler 1998

7

Hamlin Valley Pyrg Pyrgulopis hamlinensis • Very small only reaching up to 1.6-2 mm • Narrow conical shell • Aperture ovate, usually disjunct • Only found in White Rock Cabin Springs

Krissy Wilson, UDWR Hershler 1998

Carinate Glenwood Pyrg Pyrgulopsis inopinata

• 2.9-3.5 mm, 5-5.75 whorls • Narrow conical shell • Sutures shallow • Final whorls have weak angulation or

narrow keel • Aperture ovate, slightly disjunct from

whorl • Only known springsnail in Utah with

carinate shell • Endemic to springs near Glenwood,

Sevier drainage • Occurs in same habitats with

Smooth Glenwood Pyrg

Hershler 1998

8

Toquerville Springsnail Pyrgulopsis kolobensis • 2.8-4 mm, 3.75-4 whorls • Ovate shell • Aperture ovate • Similar to pyrgs throughout Great

Basin, only found in Ash Creek, Virgin Drainage

• Region: S Hershler 1998

Lindahl’s Pyrg Pyrgulopsis lindahli

• 3.0-3.7 mm, 4-4.75 whorls • Ovate shell • Aperture ovate • Documented only in Zion National

Park • Region: S

Hershler et al. 2017

Ninemile Pyrg Pyrgulopsis nonaria • 2.5-2.9 m, 4.5-5 whorls • Ovate shell • Aperture ovate, slightly disjunct

from whorl • Only found at springs near

Ninemile Reservoir • Region: C Hershler 1998

9

Nuwuvi Pyrg Pyrgulopsis nuwuvi • 3.2-4 mm, 4.5-5 whorls • Narrow conic shell • Aperture ovate • Documented only in Pine Valley

Mountains • Region: S

Hershler et al. 2017

Bifid Duct Pyrg Pyrgulopsis peculiaris

• 1.7-3 mm • Ovate shell • Ovate aperture, slightly disjunct

from whorl • Only found in Millard County, UT

and White Pine County, NV • Region: S

Hershler 1998

Bear Lake Springsnail Pyrgulopsis pilsbryana • 3.5-4 mm, 4 whorls • Ovate shell • Last suture very deep • Only found in Bear Lake and Bear

River Drainages • Region: N

10

Pine Grove Pyrg Pyrgulopsis pinetorum • 2.8-3.6 mm, 4-4.5 whorls • Ovoid shell • Only found in Pine Valley

Mountains • Region: S

Taylor 1987

Black Canyon Pyrg Pyrgulopsis plicata

• 2.3-2.9 mm, 4-4.5 whorls • Ovate shell • Aperture large, ovate, often

disjunct from body whorl • Endemic to springs in Black

Canyon adjacent to East Fork Sevier River Hershler 1998

• Region: S

Santa Clara Pyrg Pyrgulopsis santaclarensis

• 3-3.75 mm, 4-4.5 whorls • Ovate to narrow conic shell • Aperture ovate • Documented only in Pine Valley

Mountains • Region: S Hershler et al. 2017

11

Sub-globose Snake Pyrg Pyrgulopsis saxatilis • 1-1.4 mm, 3.5-4 whorls • Sub-globose shell • Aperture ovate • Shoulders well-developed • Endemic to Gandy Warm Spring

Hershler 1998

Southern Bonneville Pyrg Pyrgulopsis transversa

• 2-3.1 mm, 4.25-5.25 whorls • Ovate shell • Aperture ovate, disjunct from

body whorl Hershler 1998 • Region: C

Northwest Bonneville Pyrg Pyrgulopsis variegata

• 2.2-3 mm, 4.25-5 whorls • Ovate shell • Body whorl disjunct from aperture • Aperture ovate • Regions: N, C Hershler 1998

12

Phylum: Mollusca Class: Gastropoda

Family: Lithoglyphidae This family consists of pebblesnails. They are small snails with squat shells. Green River Pebblesnail Fluminicola coloradoensis

• Larger than springsnails (7-9 mm), 4-5 whorls • Sub-globose shell • Sutures indistinct • Aperture teardrop-shaped • Found in Green River and Wasatch Front • Regions: NE, SE

13

Phylum: Mollusca Class: Gastropoda

Family: Valvatidae Valvatas or valve snails are very small snails (4 to 8 mm) with a deep umbilicus. Their whorls increase in size or diameter from the apex or center. The apertures are round and the operculum is circular and translucent. Glossy Valvata Valvata humeralis

• Small shell, > 5 mm • More compressed than

Desert Valvata • Lacks ridge

http://www.stitchingnature.com Desert Valvata Valvata utahensis

• Small, 4-7 mm • Somewhat top-shaped • Ridge along spiral almost to

aperture • Historically found in Utah Lake • Likely extirpated from Utah Lysne 2009

14

Phylum: Mollusca Class: Gastropoda

Family: Lymnaeidae Lymnaeids are marshsnails or pondsnails. They occur in lakes, swamps, or springs. They have dextral apertures and lack opercula. They usually have thin, elongate shells. The columellar lip often curves to the outside. Prairie Fossaria Galba bulimoides

• 5-10 mm • Spire conical with large

distended body whorl • Columellar lip folded back • Region: S

http://www.conchology.be

Dusky Fossaria Galba dalli • Less than 7 mm, 5 whorls • Whorls shouldered • Aperture elongate and elliptical • Records from Temple of

Sinewava in 1977 (mis- identified?)

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Fossaria_dalli.htm

15

Rock Fossaria Galba modicella • 7-10.5 mm, 4-5 whorls • Aperture ovate, narrowed above

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Fossaria_modicella.htm

Golden Fossaria Galba obrussa • 9-13 mm, 5 whorls • Thin shell • Pointed spire • Body whorl very large (half

length of shell) • Inner lip oppressed to aperture

about the middle of the aperture _

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Fossaria_obrussa.htm

16

Pygmy Fossaria Galba parva • 4.5-9 mm • 5 whorls • Shell solid and turreted • Sutures deep • Round aperture • Regions: N, C, SE

Rusty Fossaria Galba rustica

• 7.5-10 mm • 5 whorls • Long, acute spire • Sutures impressed

Unnamed Fossaria Galba techella

• Probably similar to Prairie Fossaria- considered by some to be a subspecies

• Regions: NE, S

http://www.boldsystems.org

17

Swamp Lymnaea Lymnaea stagnalis • 7 whorls • Large shell (30-53 mm) • Long spire • Sutures distinct, may be

impressed • Two subspecies described in

Utah: jugularis and wasatchensis

Fat-whorled Pondsnail Stagnicola bonnevillensis

• Less than 30 mm • 4 whorls • High cone-shaped

shell • Region: N

Moonlight Limnology, North Logan, Utah

18

Wrinkled Marshsnail Stagnicola caperata

• 9-13 mm • 6 whorls • Shell solid • Spiral lines give latticed

appearance • Sutures heavily impressed • Inner lip folded over in a

triangle http://www.fwgna.org/species/lymnaeidae/l_caperata.html

Marsh Pond Snail Stagnicola elodes

• Large shell up to 32 mm • Up to 7 whorls • May have spiral bands • Aperture is kidney shaped • Aperture is much smaller than the

length of entire shell • Columella is highly twisted

http://www.fwgna.org/species

/lymnaeidae/l_elodes.html

19

Mountain Marshsnail Stagnicola montanensis • Globose shape • Columella lightly twisted

Fish Springs Marshsnail Stagnicola pilsbryi NO PHOTO AVAILABLE

• Probably extinct • Was found only from Fish Springs, Juab County

Unnamed lymnaeid Stagnicola sumassi

NO PHOTO AVAILABLE • Narrow, elongate shell • Only record from Echo Canyon, Summit Co.

Widelip Pondsnail Stagnicola traski NO PHOTO AVAILABLE

• Short spire • Rotund body whorl • Known from two sites: Ogden Canyon, and Garfield

20

Thickshell Pondsnail Stagnicola utahensis • Last observed in Utah Lake in

1930s • 4 Whorls • Irregularly ribbed • Globose shell • Small spire • Oval aperture

Big-ear Radix Radix auricularia • INVASIVE – native to

Europe and Asia • 23-30 mm • Globose shape • Ear-shaped aperture • Thin shell • Shell tan or yellow • Usually found in reservoirs,

ponds

21

Phylum: Mollusca Class: Gastropoda

Family: Physidae

Physids are the most abundant and widespread family of gastropods in North America. They can be found in all aquatic habitat types and their abundance is indicative of food availability and space. They typically have a large body whorl and lack an operculum. Unlike Lymnaeids, the spires are not as elongate and they are sinistral (left-handed aperture opening). Lance Aplexa Aplexa elongata

• Up to 20 mm • 6 whorls • Spindle-shaped • Aperture elongate, half the

length of shell • Thin transparent shell

http://www.personal.umich.edu/~daviscj/species%20pictures.html

22

Cloaked Physa Physa megalochlamys • Up to 11 mm • Low, cone-shaped shell • Glossy • Only Utah record is in Bishop

Springs, Millard Co. • Gills cover part of shell in living

individuals • Region: S

Glass Physa Physa skinneri

• Regions: N, C

Tadpole Physa Physella gyrina • About 20 mm, 5-6 whorls • Smooth surface • Oval aperture • Extremely variable

hhttp://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Physella_gyrina.htm

23

Polished Physa Physella mexicana

• Oval-shaped shell • Shell dull (not glossy) • Columellar fold widely

expanded http://www.bagniliggia.it/WMSD/HtmSpecies/5602000029.htm

Fish Lake Physa Physella microstriata NO PHOTO AVAILABLE

• Probably extinct • Documented only from Fish Lake

Rocky Mountain Physa Physella propinqua NO PHOTO AVAILABLE

• Prefers permanent cool habitats like lakes • Many observations in Southern Idaho (Bear Lake) • Only one record of occurring in Box Elder Co.

Utah Physa Physella utahensis

• Up to 14 mm • Low cone-shaped shell • Glossy • Regions: N, C, S

24

Protean Physa Physella virgate • 4-5 whorls • Shell elongate • Shell ash-colored with stripes

Wet-rock Physa Physella zionis

• 4.5 mm • 2.5 whorls • Egg-shaped shell (nearly spherical) • Aperture nearly as long as shell • Glossy • Only found in tributaries of North Fork

Virgin River Narrows

Photo Copyright Ann Buddenhagen

25

Phylum: Mollusca Class: Gastropoda

Family: Planorbidae

Planorbids are ramshorns, gyros, and ancylid snails. They can be found in many habitat types but prefer lakes or ponds on firm mud substrate with decaying vegetation for food. They have flattened helical shells with the spire sunken in the middle. They are sinistral (although difficult to tell because of shape). They have no operculum.

Disc Gyro Gyraulus circumstriatus

• 3-5 mm diameter • 4-5 whorls • Flattened shell, nearly same on

both sides • Aperture roughly circular

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Gyraulus_circumstriatus.htm

26

Ash Gyro Gyraulus parvus • Up to 7 mm diameter • Shell not completely flattened • Narrow umbilicus • Whorls enlarge gradually

www.personal.umich.edu/~ www.jaxshells.org daviscj/gyraulus_parvus_crane_top.jpg

Two-ridge Ramshorn Helisoma anceps

• Up to 22 mm diameter • 4-5 whorls • Strong shell • Distinctive ridge on both sides • Deep umbilicus • Aperture ear-shaped

www.fwgna.org/species/planorbidae/h_anceps.html

27

Great Basin Ramshorn Helisoma newberryi

• 13 mm diameter • Stout shell • Spire convex • Sharply angled shoulders • Formerly in Utah Lake • May now be extirpated

from Utah Button Sprite Menetus opercularis

• Ridge along outer edge of whorls

Course Ramshorn Planorbella binneyi

• Large: up to 36 mm • Very wide whorls • Whorls increase rapidly

http://www.stitchingnature.com/Snails/Mollusca/Gastropoda/Planorbidae/Planorbidae006.htm

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Planorbella binneyi.htm

28

Meadow Ramshorn Planorbella campestris • Prefers vegetated

wetland or ephemeral pools

• 3-4 whorls • Round aperture • Last report in UT

is from Burch, 1989

Lamb Ramshorn Planorbella oregonensis NO PHOTO AVAILABLE

• Only Utah record from Salt Springs but identification is questionable

• Region: C Rough Ramshorn Planorbella subcrenata

• Up to 32 mm diameter

• Less than 10 mm high

• Loosely coiled whorls (3)

• Sutures deep • Spire sunken

http://explorer.natureserve.org/servlet/NatureServe?searchName=Planorbula+campestris

29

Marsh Ramshorn Planorbella trivolvis

• Up to 32 mm diameter • Less than 10 mm high • 4 whorls • Whorls on one plane • Aperture moon-shaped

Sharp Sprite Promenetus exacuous

• Up to 6 mm diameter • 4 whorls • Very flattened, with ridge

along outside edge of last whorl

• All whorls in same plane

http://www.uwlax.edu/biology/faculty/perez/wifwsnailkey/Promenetus_exacuous.htm

http://www.inaturalist.org/observations/150119

30

Creeping Ancylid Ferrissia rivularis • Up to 7 mm length, 4 mm

width • Fragile, limpet-like shell • Apex leans slightly to right

31

Phylum: Mollusca Class: Gastropoda

Family: Viviparidae

Commonly referred to as river or mystery snails, these large aquatic snails have an operculum and gills. They are grazers as well as filter feeders competing with clams and mussels. They occur globally with 17 species in North America, 14 in India, 12 in China, and 6 in Australia, Africa, and Europe. Chinese Mystery Snail Bellamya chinensis

• INVASIVE. Native to East Asia • Large shell, up to 65 mm • Smooth shell surface • 6-7 whorls • Documented in Goshen Ponds, Utah Co.

http://en.wikipedia.org/wiki/Chinese_mystery_snail

32

Phylum: Mollusca Class: Gastropoda

Family: Thiaridae Also referred to as the melanias, this is a family of tropical freshwater snails that occur worldwide and are invasive in some regions. They are long, turreted snails with an operculum. Some species in this family are parthenogenic. Red-rimmed Melania Melanoides tuberculata

• INVASIVE. Native to northern Africa and southern Asia

• Slender, high-spired shell, 30-40 mm. • Shell has reddish spots and “flames” • Found in isolated warm springs • Spiral operculum

33

Phylum: Mollusca Class: Gastropoda

Family: Tateidae Tateidae is a family of minute snails with an operculum, including the New Zealand Mudsnail. This family was formerly part of Hydrobiidae. New Zealand mudsnail Potamopyrgus antipodarum

• INVASIVE. Native to New Zealand • 3-6 mm long, 5-7 whorls • Whorls thin, may have weak keel • Sutures distinct but not deep • Oval aperture sitting to the right of

the spire • High, narrow spire • Parthenogenic • Can live in all aquatic habitat types • Notify UDWR Salt Lake office immediately if found

http://www.tsusinvasives.org/home/database/potamopyrgus-antipodarum

34

TERRESTRIAL SNAILS

In general, terrestrial snails are more land-dwelling, although many are amphibious, living in wet habitats. Most have lungs and breathe air and lack opercula classifying these snails as pulmonates. Most have dextral shells, although this group includes slugs that do not have shells. Phylum: Mollusca Class: Gastropoda

Family: Succineidae This family consists of the ambersnails. These are fragile, translucent snails usually with amber-colored shells. They have a large body whorl and dextral aperture. They mostly occur in damp habitats like marshes. Suboval Ambersnail Catinella avara

• Up to 6 mm • 3 whorls • Deep sutures • Spire prominent • Aperture oval

http://www.bagniliggia.it/WMSD/HtmSpecies/4270000000.htm

35

Sierra Ambersnail Catinella stretchiana

• Only Utah record near Brigham City

• Region: N Niobrara Ambersnail Oxyloma haydeni

NO PHOTO AVAILABLE • Similar to Kanab Ambersnail, which is sometimes

considered a subspecies • Short spire • Up to 21 mm • 3 whorls

Kanab Ambersnail Oxyloma kanabensis

• ENDANGERED • Up to 19 mm • Short, drawn-out spire and larger long body whorl

Only Utah location is Three Lakes near Kanab • Genetics in question; may be synonymous with

Niobrara Ambersnail • Region: S

http://en.wikipedia.org/wiki/Kanab_ambersnail Jeff Sorenson, AZGF

36

Oblique Ambersnail Oxyloma nuttallianum

• Oblong-ovate shell • 17mm long x 9mm width • Short spire with 3 whorls

Blunt Ambersnail Oxyloma retusa

• Reported from Kane, Garfield counties

http://www.conchology.be/?t=66& family=SUCCINEIDAE&species= Oxyloma%20retusa

Santa Rita Ambersnail Succinea grosvenori

• Shell oval, 4 whorls • Sutures impressed • Aperture large and rounded • Columella bent in and twisted • Regions: N, C, SE

Rustic Ambersnail Succinea rusticana

NO PHOTO AVAILABLE • Elongate shell, Course growth lines • Regions: N, C

37

Phylum: Mollusca Class: Gastropoda

Family: Cochlicopidae These are also referred to as pillars. These are land snails with pillar-like, smooth, glossy shells that they cleanse themselves with their radula. They can be found in valley meadows, flood plains, hiding under grasses, duff, rotten wood and leaf litter. Glossy Pillar Cochlicopa lubrica

• Up to 6 mm • Small, thin shell • 5-6 whorls • Body whorl rounded

http://academic.evergreen.edu/proj ects/ants/TESCBiota/mollusc/key/ coc_lub/coc_lub.htm

38

Phylum: Mollusca Class: Gastropoda

Family: Pupillidae These snails are also referred to as columns and daggers with very small cylindrical shells but typically larger than whorl snails (Vertiginidae). These are also called chrysalis snails as their shells resemble a butterfly chrysalis. Some may also have “teeth” within their aperture. They are globally widespread.

Rocky Mountain Column Pupilla blandi • Shell oval-cylindrical • 6 whorls • Small, nearly circular aperture • Three teeth (one far within

aperture) • Could be misidentified;

range in central plains of North America.

Crestless Column Pupilla hebes • Similar to Rocky

Mountain Column • Short • No teeth

http://snailstales.blogspot.com/2006_04_01_ archive.html

http://www.bagniliggia.it/WMS

39

Widespread Column Pupilla muscorum

• About 4 mm • 6-7 whorls • Anterior 4 whorls similar

width • Could be misidentified; © Copyright Malcolm Storey

range in NE USA

Top-heavy Column Pupilla syngenes

• Shell sinistral (although some are dextral)

• 8 whorls • Cylindrical, but somewhat

wider at top • Oval aperture • Utah records in Zion National

Park and Torrey • Region: S • May be lumped with Crestless Column

40

White-lip Dagger Pupoides albilabris • 5 mm • Shell tapers • 6 whorls • Oval aperture, white • Utah records from Zion National

Park • Region: S ©Rick Fridell

Ribbed Dagger Pupoides hordaceus NO PHOTO AVAILABLE

• Region: S

41

Phylum: Mollusca Class: Gastropoda

Family: Vallonidae Also referred to as vallonias or midget snails, these are tiny snails with helix-shaped shells. Less than 3 mm diameter. Indecisive Vallonia Vallonia albula

• 2.7 mm diameter • Thin shell, nearly white • Sharp ribs encircling whorls • Circular aperture

Silky Vallonia Vallonia cyclophorella • 2.6-3.3 mm diameter • Lips of aperture turned out • Oval aperture • Fine, sharp ribs

42

Multirib Vallonia Vallonia gracilicosta • 2.6 mm diameter • Transparent or white shell • Thick white lips turning out • Aperture oval • Fine, sharp ribs

h http://www.mollus.ca/canada/ species/gallery/valgra.htm

Thin-lip Vallonia Vallonia perspectiva

• Approx 2 mm wide • White to colorless shell • Utah records from

Washington and Garfield Counties

• Region: S

Lovely Vallonia Vallonia pulchella

• Non-native according to Chamberlin & Jones

• Up to 3 mm • Shell slightly convex above • Thin and transparent shell • 4 whorls

http://en.wikipedia.org/wiki/Vallonia_pulchella

http://mypage.siu.edu/mlcopp/images/spp_images/Vallonia_perspectiva.jpg

43

Phylum: Mollusca Class: Gastropoda

Family: Vertiginidae

These are also called columns, snaggletooths, or whorl snails. They are minute, columnar snails. Most have tooth projections in aperture. Mellow Column Columella columella

• 2.5-3.5 mm • 7-8 whorls • Long, cylindrical • Light brown with lighter apex • Last whorl (closest to aperture) a

little larger than following 3 whorls

• No teeth http://en.wikipedia.org/wiki/Columella_columella

Sluice Snaggletooth Gastrocopta ashmuni

• Only Utah record in Zion National Park

• Region: S

http://www.madrean.org/symbfauna/imagelib/imgdetails.php?imgid=191993

44

Slim Snaggletooth Gastrocopta pellucida • Parietal denticle long and bilobed • Region: SE

RosGaryenberg, 2005-2011

Montane Snaggletooth Gastrocopta pilsbryana

• 2.1 mm • 5 whorls • Teeth present • Region: S

http://www.madrean.org/symbfauna/imagelib/imgdetails.php?imgid=192018

Cross Snaggletooth Gastrocopta quadridens NO PHOTO AVAILABLE

• Region: C, S

45

Mitered Vertigo Vertigo concinnula

• 2 mm • 5 Whorls • Blunt apex • Chestnut brown, shiny • Region: C, S

http://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=304140

Tapered Vertigo Vertigo elatior

• 2.1-2.2 mm • 5 teeth in aperture • Tan or cinnamon shell • Region: NE

http://bioweb.uwlax.edu/bio210/2011/schmidt_holl/

Variable Vertigo Vertigo gouldii

• Brown, shiny shell • 4 brown teeth within aperture • Regions: N, S, SE

© Gary Rosenberg, 2005-2011

46

Cross Vertigo Vertigo modesta • 4-5 whorls • Large aperture with 4-5 thick teeth

Ovate Vertigo Vertigo ovata

• Only Utah record from Fruita • Region: S

http://www.carnegiemnh.org/ science/default.aspx?id=21713

47

Phylum: Mollusca Class: Gastropoda

Family: Punctidae Also referred to as spots. These are very minute snails with umbilicated shells (having a depression in the middle).

Small Spot Punctum minutissimum

• 1 mm, 4 whorls • Utah’s smallest snail • Shell subglobose • Shell reddish, shiny

http://en.wikipedia.org/wiki/Punctum_minutissimum

48

Phylum: Mollusca Class: Gastropoda

Family: Discidae

These are also considered discs or tiger snails. Striate Disk Discus shimekii

• 5-6.5 mm, 4 whorls • Thin, greenish shell,

streaked and dotted

• Irregular striations on whorls

• Convex spire • May prefer high

elevation habitats

Forest Disk Discus whitneyi • 5 mm • 3 ½ whorls • Strongly ribbed

https://bioweb.uwlax.edu/bio210/2011/check_ryan/classification.htm

49

Phylum: Mollusca Class: Gastropoda

Family: Helicodiscidae

Also called coils, this family is made up of small-shelled snails with an open umbilicus. Mexican Coil Helicodiscus eigenmanni

• Striated ridges or lines around the shell • Open or semi sunken umbilicus

Region SE

https://www.inaturalist.org/observations/2648746

50

Phylum: Mollusca Class: Gastropoda

Family: Oreohelicidae Oreohelicidae encompasses the mountain snails. These snails typically have solid, opaque shells, unreflected lip, and a widely open umbilicus. Many species have dark bands circling with the whorls. The genus Oreohelix is ovoviviparous (eggs hatch internally). Eureka Mountainsnail Oreohelix eurekensis

• 9-10 mm • 4 ½ whorls • Spire slightly elevated • Endemic to Utah • Can be found around

8,000 ft. elevation and on dead leaf matter and base of aspen trees

• 4 populations known • Regions: C, NE, SE

51

Lyrate Mountainsnail Oreohelix haydeni

• 18-23 mm • Vary variable shell

characteristics • Sharp spiral ribs • Regions: N, C

White Pine Mountainsnail Oreohelix hemphilli

• 8-12 mm diameter • Keeled outer body whorl • Whorled ridges on both

top and bottom • Known from Deep Creek Range

Ports 2004

Mill Creek Mountainsnail Oreohelix howardi

• Known only from Mill Creek Canyon, Salt Lake County

• Region: C

52

Brian Head Mountainsnail Oreohelix parawanensis • 5-10 mm diameter • Known only from Brian

Head Peak • Region: S

Deseret Mountainsnail Oreohelix peripherica

• 29-23 mm diameter • Shell appears wrinkled • O.p. wasatchensis

former candidate for listing

• Region: N

Rocky Mountainsnail Oreohelix strigosa

• Up to 20 mm diameter • Spire elevated • Several color bands • Widespread

53

Subalpine Mountainsnail Oreohelix subrudis • Statewide, records in

mountains Yavapai Mountainsnail Oreohelix yavapai

• 12-14 mm diameter • Found only on Navajo

Mountain and Abajo Mountains

• Region: SE

54

Phylum: Mollusca Class: Gastropoda

Family: Gastrodontidae These are also referred to as the glosses. They are small helical snails with shiny, sometimes colorful shells. These snails are also called the dagger snails as they have a “love-dart” and a dart sac as a reproductive stimulator in males. Quick Gloss Zonitoides arboreus

• 5 mm diameter • 4-5 whorls • Very slightly convex • Smooth, amber-colored shell • Deep umbilicus

Black Gloss Zonitoides nitidus • 6-7.5 mm diameter • 5 or more whorls • Red or brown shell

with radial growth lines and orange mantle gland

• Umbilicus is very wide and convex • Prefers humidity found in wet meadows or alluvial

forests • Regions: N, C

http://www.molluskennrw.de/forschung/artenliste.htm

55

Phylum: Mollusca Class: Gastropoda

Family: Euconulidae These are the hive snails. They are minute snails most only get up to 3 mm in size with conical, broad-based shells that resemble a hive and are usually amber colored and translucent. Brown Hive Euconulus fulvus

• 4 mm diameter • 4-5 whorls • Spire elevated • Shiny yellowish

shell

http://bioweb.uwlax.edu/bio210/2011/ fitzsimm_alec/

56

Phylum: Mollusca Class: Gastropoda

Family: Oxychilidae These are also called glass snails. They are small helical snails similar to hive snails. Indented Leaf Snail Glyphyalinia indentata

• 4-6 whorls • Smooth, shiny shell • Umbilicus indented

Texas Glyph Glyphyalinia umbilicata

• 4-6 whorls • Smooth, shiny shell • Narrow umbilicus

hhhttp://www.jaxshells.org/last1.htm

57

Amber Glass Nesovitrea electrina: • Slightly rounded apex • Shiny, amber-colored,

translucent shell • Irregularly spaced

grooves that fade from top to bottom

© Robert Forsyth (Photo ID #15495)

Cellar Glass-Snail Oxychilus cellarius

• INVASIVE. Native to Western Europe

• Larger than native Oxychilidae; 9-14 mm

• May be seen in parks, urban areas

58

Phylum: Mollusca Class: Gastropoda

Family: Pristilomatidae These are called gems. They are small helical snails also similar to hive snails. Minute Gem Hawaiia minuscula

• Domed spire • Shell surface appeared wrinkled • Umbilicus about 1/3 shell diameter • Known from Deep Creek Range • Region: C

http://commons.wikimedia.org/wiki/File:Hawaiia_minuscula_shell.jpg Striate Gem Hawaiia neomexicana

NO PHOTO AVAILABLE • Region: S

59

Southern Tightcoil Ogaridiscus subrupicola 3-4 mm

• Only Utah record in Clinton’s Cave, Tooele County.

• Region: C

60

Phylum: Mollusca Class: Gastropoda

Family: Vitrinidae These are considered semi-slugs. They are small snails with shells so small that they are not able to retract.

Western Glass-Snail Vitrina pellucida • Small, shiny,

transparent shell • Short spire • 2-3 whorls • Aperture moon-

shaped

© Richard Fridell

61

Phylum: Mollusca Class: Gastropoda

Family: Thysanophoridae These woodland snails are common in North America. They are small helical or flattened snails with thin or fragile shells. Spruce Snail Microphysula ingersolli

• Many whorls (6 or more)

• Flat or nearly flat spire • Small umbilicus • Moon-shaped aperture

http://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=320971

62

Phylum: Mollusca Class: Gastropoda

Family: Subulinidae

These are small tropical land snails that are non-native to Utah but are distributed worldwide. The only species of this family in Utah is the decollate snail, a predatory species. Decollate Snail Rumina decollata

• INVASIVE. Native to Mediterranean Europe

• Often introduced as a biological control for Brown Garden Snail

• Long, cone-shaped shell • Top of spire nearly always

broken off • Established in urban areas

of Washington County • Notify UDWR Salt Lake office immediately if found

63

Phylum: Mollusca Class: Gastropoda

Family: Helicidae

Helicidae is a large and diverse family of various-sized land snails, typically referred to as garden snails or typical land snails. Brown Garden Snail Cornu aspersum

• INVASIVE. Native to Europe

• Large shell (25-40 mm in diameter)

• 4-5 whorls • Shell often brown

with yellow stripes, flecks, or streaks

• Shell is globular in shape http://en.wikipedia.org/wiki/Helix_aspersa

64

Phylum: Mollusca Class: Gastropoda

Family: Polygyridae Southern Flatcoil Polygyra cereolus

• INVASIVE Native to SE United States

• Flat shell, usually about 8mm diameter

• 6-8 whorls • Documented in

Washington County

65

Phylum: Mollusca Class: Gastropoda

Family: Agriolimacidae This family consists of small and medium-sized land slugs; terrestrial pulmonate gastropod mollusks. Mantle has concentric ridges. Mantle has pnuemostome (a hole for breathing). Tail may be keeled. Marsh Slug Deroceras laeve

• 25-35 mm long • Bluish-black tentacles • Dissection of genitalia

may be required to tell from Gray Fieldslug

http://idtools.org/id/mollusc/factsheet.php?name=Deroceras%20laeve

Gray Fieldslug Deroceras reticulatum

• INVASIVE. Native to Western Europe • Widespread in populated areas • Up to 50 mm long • Gray or cream-colored

with dark reticulations • Dissection of genitalia

may be required to tell from Marsh Slug http://idtools.org/id/mollusc/factsheet.php?

name=Deroceras%20reticulatum

66

Phylum: Mollusca Class: Gastropoda

Family: Limacidae

These are also called Keeled slugs. These are large air-breathing slugs. Utah has only one species of this family and it is invasive. Giant Gardenslug Limax maximus

• INVASIVE. Native to Europe

• Large (longer than 25 mm) • Striped and spotted and thus

also called leopard slug

http://en.wikipedia.org/wiki/Limax_maximus

67

BIVALVES Kingdom: Animalia Phylum: Mollusca Class: Bivalvia

Utah bivalves include freshwater mussels and clams although this class also includes marine clams, oysters, scallops, and mussels. None are terrestrial. All have two shells (valves) and a laterally hinged body. Bivalves are diecious and reproduce sexually, although females of some species can be hermaphroditic when males are limited. Bivalves are suspension or filter feeders by use of anterior siphons and/or cilia to pass water and food over their internal gills which are used for respiring as well as feeding. Most bivalves have a muscular “foot” that can reach out of the shell to be used to burrow or move although bivalves are mostly sedentary.

http://www.molluscs.at/bivalvia/index.html?/bivalvia/lesser_mussels.html

68

FRESHWATER MUSSELS Freshwater mussels are a very diverse group of mollusks that are found globally with the most diversity in North America, yet are also highly imperiled. They are sensitive to pollution and climate change, making them indicator species. They also provide vital ecosystem services in aquatic systems such as water filtering and particle suspension. Most freshwater mussels have a unique life-history which involves the use of a host-fish. Once a female is fertilized, she will release her larvae, called glochidia, into the water column in masses or mucus-like sacs for their specific species of host-fish or fishes to ingest. The glochidia then encyst onto the gills of the fish where they develop into juveniles and eventually detach from their host-fish. This co-evolutionary relationship allows for mussel dispersal by traveling on fish as well as protection during development. The two families of freshwater mussels in Utah include the pearlshells and unionids or river mussels.

69

Phylum: Mollusca Class: Bivalvia Order: Unionoida Family: Margaratiferidae Margaratiferidae are the pearlshells as their inner nacre is able to produce pearls. They are usually dark brown or black mussels with shells slightly concave and a ventral margin. Western Pearlshell Margaritifera falcata

• Large (80+ mm) long • Thick, kidney shaped shell • Inflated shell • Regions: N, C • Host-fish: Rainbow trout,

Brown trout, Cutthroat trout, Chinook Salmon, Steelhead trout

http://www.jaxshells.org/falco.htm

http://mkohl1.net/Margaritiferidae.htmlesg.montana.edu/aim/mollusca/marfal.html

70

Phylum: Mollusca Class: Bivalvia Order: Unionoida Family: Unionidae Unionidae is the largest family in the order Unionoida. These are also called unionids or river mussels. The only unionid genus in Utah is the floater (Anodonta). These are large oval and elongate freshwater mussels with thin shells, a simple hinge, slightly curved line, and no hinge teeth. Winged Floater Anodonta nuttalliana

• Large (70+ mm) • Thin shell with a dorsal “wing” • Flattened, egg-shaped shells • Regions: N,C, S • Floaters found in Utah were formerly known as

California Floater, but have been lumped with Winged Floater.

• Host-Fish: speckled dace, torrent sculpin, redside shiner, stickleback

71

Paper Pondshell Utterbackia imbecillis • Non-Native • Native to Mississippi and eastern U.S. drainages • 60-80 mm length • Documented in Cutler Reservoir, northern region • Thin shell, flattened beak (umbo)

http://www.jaxshells.org/1113xr.htm

72

Phylum: Mollusca Class: Bivalvia Order: Veneroida Family: Dreissenidae Dreissenidae are a family of freshwater mussels that are non-native to North America. Two species, Zebra Mussels and Quagga Mussels, have invaded North America and have adapted to living in various regions of the country. Drissenids reproduce sexually. Instead of glochidia or use of host-fish, they have free swimming veligar larvae that mature to adults. They use bissall threads to attach to surfaces. They are triangular-shaped shells with a distinct inside curve and a ridge. They are about 25-40 mm. Some have stripes on outer shells. Quagga Mussel Dreissena bugensis

• INVASIVE • Native to Eastern

Europe • Dark concentric rings

on shells • Two valves are

asymmetrical • Established in Lake

Powell • Notify UDWR Salt Lake office immediately if found

http://www.100thmeridian.org/zebras.asp

73

FRESHWATER CLAMS Freshwater clams are a diverse group of small bivalves, all with a very similar size, shape, and color. They are also filter feeders, sedentary, and burrowers. They also reproduce sexually and release hatched juveniles into the substrate to mature to adults. Phylum: Mollusca Class: Bivalvia Order: Veneroidia Family: Sphaeriidae Shpaeriidae are the peaclams, pill clams, and fingernail clams which are small freshwater bivalves, most are less than 12 mm in length with very thin shells. These species appear very similar, and recent taxonomic information is sparse. This family now includes clams that were formally placed in Pisidiidae. Lake Fingernailclam Musculium lacustre

• Small, triangular shells • Includes former

Musculium ryckholti http://www.biolib.cz/en/image/id1599/

74

Swamp Fingernailclam Musculium partumeium • Rhombic

(diamond-shaped) shell

• Reported as Musculium truncatum from S. Cottonwood Canyon

• Region: C http://mkohl1.net/Sphaeriidae.html

Ubiquitous Peaclam Pisidium casertanum

• 3-3.5 mm long • Thin, oval shell • High, well-rounded shell • Found statewide • Includes former “species”

P. abditum, P. concinnulum, P. huachucanum

Ridgebeaked Peaclam Pisidium compressum

• 3.1-3.5 mm long • Triangular shells • Hinge side of shells pronounced • Shell height is greater than

length http://www.museumoftheearth.org/outreach.php?page=s_hsh_top/s_hsh_s3_biodiv/s_hsh_s3_flip1&id=8

75

Lilljeborg Peaclam Pisidium lilljeborgi • Characteristic of lakes at

high altitudes • Heavy striae • Distinct off center beak

Quadrangular Pillclam Pisidium milium

• Small shell 3-4.5mm • Very inflated and rectangular

in shape • Shape is tumid or swollen • Broad swollen umbo • Glossy with irregular striae

Fat Peaclam Pisidium rotundatum

• Small, glossy shell • Shell inflated, pea-like • Umbo subcentral

https://idfg.idaho.gov/species/taxa/25122

https://www.latvijasdaba.lv/gliemji/pisidium-lilljeborgii-clessin/

https://idfg.idaho.gov/species/taxa/22303

76

Short-ended Peaclam Pisidium subtruncatum • Small, well inflated

shell • Reported as Pisidium

marci from Mount Leidy

• Region: NE Triangular Peaclam Pisidium variabile

• Large, solid, glossy shell • Anterior end pointed

http://www.boldsystems.org/ index.php/Taxbrowser_Taxon page?taxid=600789 Globular Peaclam Pisidium ventricosum

• Round, thin, inflated shell • Swollen beak, light striae • Prefers muddy substrate with

vegetation • Found in most aquatic habitat

types

http://www.animalbase.uni-goettingen.de/zooweb/servlet/AnimalBase/home/picture?id=2387

http://www.invertebase.org/portal/taxa/index.php?taxon=20922

77

Arctic Fingernailclam Sphaerium nitidum

• Shell small, thin, rounded • Swollen beak • Reported as Musculium

uintaense from a lake in the Uinta Mountains

• Regions: N, NE http://www.stitchingnature.com/SpeciesPage/SphaeriumNitidum.htm

Herrington Fingernailclam Sphaerium occidentale

• Small <8mm • Very light striae that

fades towards the beak

• Distinct beak • Darker in color

https://canadianmuseumofnature.wordpress.com/2015/07/21/tiny-clams-that-thrive-in-dry-ponds/

78

Striate Fingernailclam Sphaerium striatinum

• Large, equilateral shell • Distinct striae • Reported as Sphaerium

pilsburyanum from Bear Lake and Utah Lake, and probably S. mormonicum from Salt Lake

http://www.stitchingnature.com/SpeciesPage/sphaeriumStriatinum.htm

79

Phylum: Mollusca Class: Bivalvia Order: Veneroidia Family: Corbiculidae These are commonly known as good luck clams or basket clams. These are nonnative to North America. They are medium to large in size with inflated and rounded shells. Usually have distinct ribbed shells that are brown or dark in color. They are ovoviviparous with internal fertilization and hatching of juveniles that are then released. Asian Clam Corbicula fluminea

• INVASIVE. Native to Asia • 50-65 mm in length • Oval shell with thick growth rings • Prominent beak or umbo

Illinois Natural History Survey Mollusk Collection

80

Glossary Illustrations by Pamela Wheeler

shell anatomy of a conical/ bulimoid snail

shell anatomy of a heliciform snail

81

exterior anatomy of a mussel valve

interior anatomy of a mussel valve anterior – situated on the body toward the head aperture – the opening of a snail shell, from which the snail extends its head and foot

82

apex – the top or most central whorls of a snail shell, where the earliest growth occurred apical – on the top of a shell, opposite the base base – the underside or ventral side of a shell, opposite the apical side basal – refers to the lower or ventral surface of the shell beehive – shell shaped as a traditional beehive bivalve – a mollusk with two hinged shells, including freshwater and saltwater clams, mussels, and oysters body whorl – the outermost and larges whorl of a shell; a complete round from the aperture bulimoid – a shell shape that is higher than wide

83

callus – a thickened area of shell material columella – the central axis of a spiral shell conical – a shell shape that is broad at the base and tapers to a point depressed heliciform - a shell shape that is wider than high dextral - “right-handed.” Used to describe the direction of the twist of the shell for snails. If, when holding a snail with the spire up and the aperture toward you, if the aperture is on your right, then the shell is dextral. Opposite of sinistral

84

diecious – having male or female reproductive organs in distinct individuals; having separate sexes discoidal – a very flattened, disk-like wider-than-high shell shape

epiphragm – a thin membrane of dried mucous that seals the aperture of a snail without an operculum when it is dormant foot – the flat, muscular surface of the body of a snail used for crawling gastropod – a one-shelled mollusk; includes both aquatic and terrestrial snails, slugs, and limpets

globose – a shell shape that is rounded overall

85

glochidium – parasitic larvae of some bivalves that attaches itself to the gills or fins of fish. Plural: glochidia growth lines – crosswise ridges on the shell surface that are formed during growth of a snail head – the portion of the body of a snail that contains the tentacles and mouth; anterior height – the measurement of a shell from the apex to the most basal part of the shell, parallel to the columella hermaphroditic – an organism having both male and female reproductive organs hinge – the dorsal part of a bivalve where the left and right valves attach hirsute – a descriptive term for having hairs on the surface of the shell inflated- To describe a bivalve shell as puffed up versus flat keel (of the shell) – a sharp edge of the shell, particularly prominent in some families keel (of the tail) – a ridge on the tail, present in some species

86

lip/ apertural lip/ parietal lip – the rim of the aperture of the shell, may be either sharp or thickened lirae – raised spiral cords on a snail shell

malacology – the study of mollusks mantle – the tissue that covers the organs of a mollusk. In most snails, it is within the shell, and only the edge of the mantle is visible at the aperture. In native slugs, it is located behind the head and forms a hump microsculpture – fine textural features on the surface of a shell that are best seen with a microscope mollusk – a member of the animal phylum mollusca. They have a soft body, and most have a shell or shells. They live in aquatic or moist habitats. Mollusks include snails, slugs, clams, octopi, and similar animals nacre- composite material making up an inner shell layer. The color of the nacre can be used to describe some species operculum – a hardened plate that covers the aperture when the snail is withdrawn into its shell. Common in several aquatic snails, not present in most terrestrial snails ovate – egg-shaped

87

palatal – refers to the area of the lip aperture furthest from the columella parietal denticle (tooth) – a projection from the body whorl within the aperture, present in some terrestrial species parthenogenesis – asexual reproduction where a female develops embryos without fertilization of eggs by a male to produce clone offspring periostracum – the outer layer of a snail shell; contains any color (pigment) or texture that the shell has pneumostome – the opening in the mantle that allows air to pass and allows gas exchange through the vascular tissue posterior – directional term meaning toward the tail protoconch – the smallest whorl or whorls of a shell within the center of the coil, formed during embryonic stages pseudocardinal teeth – triangular, often serrated structures located near the hinge of some bivalves radula – teeth like structures in the mouths of gastropods that are used to scrape algae from surfaces or feed in other ways ribs – raised ridges on the surface of a shell that run in an axial or crosswise direction

88

shoulder – the shelf created adjacent to the sutures of a shell before tapering downward sinistral – “left-handed.” Used to describe the direction of the twist of the shell for snails. If, when holding a snail with the spire up and the aperture toward you, the aperture is on your left, then the shell is sinistral. Opposite of dextral slug – a snail with a shell that is absent or much reduced spire – the pointed top of the shell of a snail, includes all the whorls except for the body (last) whorl spiral – the direction of the coil of the whorls; opposite of axial striae – indented lines or grooves on the surface of a shell; can be in spiral or axial direction

89

subcylidrical – a shell shape that is higher than wide subglobose – rounded or nearly spherical sublenticular – lens-shaped (bi-convex) succiniform – a shell shape that is higher than wide with a very large aperture and last body whorl sulcus – a shallow depression on the outer surface of a bivalve shell that extends from the beak to the posterior or ventral margin suture – the seam where the whorls of a shell join. Sutures may be deeply or shallowly impressed, depending on species tentacles – the sensory appendages of a snail containing the eyes turbinate – shaped like a top

90

umbilicus – an opening in the middle of the whorls at the base (bottom) of a snail shell; may or may not be present umbo – the raised portion of the dorsal portion of a bivalve shell near the hinge. Also called the beak valve – one shell of a two-shelled mollusk (bivalve) veliger – the free-swimming larvae of many mollusks whorl – one complete round of the spiral of a snail shell. Whorls are counted from the smallest central whorl outward toward the last body whorl width – the width of a shell is measured as the maximum distance across the axis perpendicular to the columella

91

REFERENCES

Bouchet, P., J.-P. Rocroi, J. Frýda, B. Hausdorf, Á. Valdés, and A. Warén. 2005. Classification and nomenclator of gastropod families. Malacologia: International Journal of Malacology 47 (1-2): 1-397.

Chamberlin, R.V. and D.T. Jones. 1929. A descriptive

catalog of the mollusca of Utah. Bulletin of the University of Utah, 19(4): 1-203.

Harrold, M.N. and R.P. Guralnick. 2010. A guide to the

freshwater mollusks of Colorado. 2nd edition. Colorado Division of Wildlife. Denver, Colorado. 132 pp.

Hershler, R. 1998. A systematic review of the Hydrobiid

snails (Gastropoda: Rissooidea) of the Great Basin, western United States: Part 1: Genus Pyrgulopsis. The Veliger 41(1): 1-132.

Hershler, R. and H.-P. Liu. 2017. Annotated checklist of

freshwater truncatelloidean gastropods of the western United States, with an illustrated key to the genera. Technical note 449. U.S. Department of the Interior, Bureau of Land Management, National Operations Center, Denver, Colorado. 141 pp.

92

Johnson, P.D., A.E. Bogan, K.M. Brown, N.M. Burkhead, J.R. Cordeiro, J.T. Garner, P.D. Hartfield, D.A.W. Lepitzki, G.L. Mackie, E. Pip, T.A. Tarpley, J.S. Tiemann, N.V. Whelan, E.E. Strong. 2013. Conservation status of freshwater gastropods of Canada and the United States. Fisheries 38(6): 247-282.

Lysne, S. 2009. A guide to southern Idaho’s freshwater

mollusks. U.S. Fish and Wildlife Service, Idaho Office. 43 pp.

Oliver, G.V. and W.R. Bosworth, III. 1999. Rare, imperiled,

and recently extinct or extirpated mollusks of Utah: a literature review. Utah Division of Wildlife Resources, Publication Number 99-29. Salt Lake City, Utah. 230 pp.

Perez, K.E. J.R. Cordeiro (Eds.). 2008. A guide for

terrestrial gastropod identification. American Malacological Society. Carbondale, Illinois. 72 pp.

Pilsbry, H.A. 1948. Land Mollusca of North America (north

of Mexico). Monographs of the Academy of Natural Sciences of Philadelphia. 4 volume set.