Zoology

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Entries - Entry Category: Zoology

Dipteran Parasites

aka: Parasitic Dipterans
aka: flies
aka: mosquitos
aka: gnats
The order Diptera belongs to the Phylum Arthropoda and Class Insecta. The order ranks number two among all insect orders—only behind beetles (Coleoptera)—with about 125,000 described species (there are an estimated 1,000,000 total species), many of which are considered parasitic or serve as vectors for diseases. There are two main groups (suborders): the Nematocera with seven infraorders and Brachycera with six infraorders. Dipterans—including the sixty species of mosquitoes that occur in Arkansas and Missouri—can be irritating to humans and harmful to livestock and other animals. A major repository of voucher specimens of dipterans in Arkansas is the Entomology Arthropod Museum at the University of Arkansas in Fayetteville (Washington County). It houses the largest research and reference collection of insects and …

Dipterans

aka: True Flies
The order Diptera belongs to the Phylum Arthropoda, Subphylum Labiata, Superclass Hexapoda, and Class Insecta. Among all insect orders, the order is number two in total number of species, ranked only behind beetles (Coleoptera), with about 125,000 described species (and an estimated 1,000,000 total species). They include house flies, blow flies, mosquitoes, gnats, black flies, midges, crane flies, horseflies, fruit flies, and others. Arkansas is home to many of these species. The first true fossil dipterans are known from the Middle Triassic Period (about 240 million years ago [mya]), and became more widespread during the Middle to Late Triassic. Although modern flowering plants did not appear until the Cretaceous (around 140 mya), the original dipterans may have had a different …

Dog Heartworms

aka: Dirofilaria immitis
The canine heartworm (Dirofilaria immitis) is a filarial parasite that belongs to the Phylum Nematoda, Class Secertenea, Order Spirurida, and Family Onchocercidae. There are two subgenera: Dirofilaria and Nochtiella. This parasite is often found in wild and domestic canids throughout the world, especially in the United States where it is endemic from the East to the Midwest, the southeastern Atlantic seaboard, and the southern Gulf Coast. Transmission of the parasite occurs throughout the United States (even Alaska) and in the warmer regions of Canada. In the United States, the highest infection rates are found within 241 km (150 mi.) of the coast from Texas northeast to New Jersey, and along the Mississippi River Valley and its major tributaries. The parasite …

Earwigs

Earwigs belong to the Phylum Arthropoda, Class Insecta, and Order Dermaptera. It is one of the comparatively species‐poor insect orders, as there are about 2,200 extant species within eleven families. About twenty-five species occur in North America, sixty in Australia, and forty-five in Europe. Earwigs are found on all continents except Antarctica and occur in northern latitudes as far north as Greenland. Earwigs exhibit their major diversity in the tropics and have a strong preference for warm and moist environments; few survive winter outdoors in cold climates. The overwhelming majority of earwig species are in the suborder Forficulina, grouped into nine families of 180 genera, including the common European earwig, Forficula auricularia. As of 2020, no earwigs have been reported …

Elk

Among the many success stories involving wildlife in Arkansas, a high-profile example is the elk of the Buffalo National River country. Wiped out in pioneer and early settlement days, the elk were brought back beginning in 1981, and, since then, the big animals have become well enough established that they can be hunted on a limited basis. The elk have also become a reliable tourist attraction in Newton County and the surrounding area. Elk were native to Arkansas but were wiped out by changing habitat, mostly the clearing of land. The variety in the area in the early days was the eastern subspecies of elk, which is extinct. By the time Arkansas became a state in 1836, elk were dwindling, …

Endemic Darters

Forty species/subspecies of darters live in Arkansas; many of them are beautifully colored, especially males during the breeding season. Of these forty, five species are endemic to Arkansas, meaning that they occur nowhere else on the planet. Those five endemic darters are the beaded darter (Etheostoma clinton), strawberry darter (Etheostoma fragi), yellowcheek darter (Etheostoma moorei), paleback darter (Etheostoma pallididorsum), and the most recently described Ouachita darter (Percina brucethompsoni). The beaded darter, Etheostoma clinton (named after Bill Clinton, the forty-second president of the United States) was described (elevated) by Richard Mayden of St. Louis University in Missouri and Steven Layman of Kennesaw, Georgia, from specimens collected in the upper Ouachita and Caddo rivers. It was formerly known as the speckled darter …

Endemic Isopods

Isopods belong to the Phylum Arthropoda, Subphylum Crustacea, Class Malacostraca, and Order Isopoda, and include pillbugs, sowbugs, woodlice, and their relatives. Isopods are cosmopolitan organisms that inhabit saltwater and freshwater habitats, including subterranean waters, but they can also be found in terrestrial environments. There are over 10,000 species of isopods worldwide in eleven suborders with about 4,500 species found in marine environments, 500 species in freshwater environments, and 5,000 species on land. Their fossil record dates back to the Carboniferous Period of the Paleozoic (some 300 million years ago) when they lived in shallow seas. Isopods range in length from thirty micrometers (microcerberid isopods) to 500 mm (19.7 in.) for the giant Antarctic isopod (Bathynomus giganteus). The majority of North …

Endemic Madtoms

aka: Ouachita Madtoms
aka: Caddo Madtoms
Two miniature catfishes are endemic to Arkansas—that is, they occur only in Arkansas and nowhere else on Earth. Both of these endemic fishes, the Ouachita madtom (Noturus lachneri) and the Caddo madtom (Noturus taylori), are taxonomically placed in the genus Noturus, the madtoms, which are contained within the catfish family Ictaluridae. Noturus lachneri was originally described by William Ralph Taylor in 1969 from the type locality of the Middle Fork of Saline River at State Highway 7, 11.2 miles (18.1 kilometers) north of Mountain Valley in Garland County. It was believed to be confined to the upper Saline River drainage until a Northeastern Louisiana University graduate student discovered it in a small tributary of the main Ouachita River just below …

Esocids

aka: Pikes
Esocids belong to the order Esociformes and family Esocidae. They were endemic to the Northern Hemisphere of North America and Eurasia during the Paleogene (66 to 23 million years before present). The only living genus is Esox (pikes and pickerels) and it includes seven species; four of those species occur in North America, and five (one introduction) of the seven can be found in Europe and Asia. In the United States, the natural range of esocids is restricted to regions east of the Rockies; however, many introductions have been made in the west. In Arkansas, there are four species: the grass pickerel (Esox americanus), northern pike (E. lucius), muskellunge (E. masquinongy), and chain pickerel (E. niger). Two of these, E. …

Exotic Fish

An exotic (or invasive) species is any plant or animal that is not native to an ecosystem and that can potentially cause economic or environmental harm, as well as damage to native animal or human health. Several species of exotic fishes in Arkansas have the capability to cause significant economic losses to fisheries and reduce opportunities for effective uses of valued aquatic natural resources. These include seven species within the minnow family Cyprinidae (now considered Leuciscidae), five species in the trout and salmon family Salmonidae, a single species of cichlid (Cichlidae), snakehead (Channidae), smelt (Osmeridae), and yellow perch (Percidae), and two species of pikes (Esocidae). CYPRINIFORMES: CYPRINIDAE (LEUCISCIDAE) Rudd or pearl roach (Scardinius erythrophthalmus). This fish apparently entered the United …

Extinct Animals [Historic Period]

Arkansas has undergone many changes over geologic time. The climate has ranged from tropical, supporting dinosaurs in the Mesozoic period, to the cold period at the end of the Cenozoic period, known as the Pleistocene epoch. The most recent drastic climate change began about 1.6 million years ago during the Pleistocene epoch, the planet’s most recent ice age. Glaciers covered much of North America. They did not reach Arkansas but occurred as far south as the Missouri River. During warm periods, the glaciers melted and sent millions of gallons of water through Arkansas on its way to the sea. Many types of animals that lived here have disappeared. If they had a hard shell or a bony skeleton, fossil records …

Extinct Animals [Prehistoric Period]

Fossils and sedimentary rock layers contribute to current knowledge of the animals that lived in Arkansas in the geologic past. A careful examination of these layers and the types of fossils contained in them reveals clues about the age of the rock and the different environments of the past. In the older deposits, evidence indicates that all of Arkansas was covered by the ocean at various times; fossils of marine animals are found as well as sequences of rock that display patterns only found in marine sedimentary deposits. In some of the most recent deposits, the remains of land animals that walked the earth just a few thousand years ago have been found. All but the most recent of the …

Fairy Shrimps

aka: Anostraca
The Order Anostraca (Phylum Arthropoda, Subphylum Crustacea, Class Branchiopoda) includes the fairy or brine shrimps. Worldwide, there are 300 species within twenty-six genera placed in eight families: Artemiidae (one genus, nine species), Branchinectidae (one genus, forty-five species), Branchipodidae (five genera, thirty-five species), Chirocephalidae (nine genera, eighty-one species), Parartemiidae (one genus, thirteen species), Streptocephalidae (one genus, fifty-six species), Tanymastigidae (two genera, eight species), and Thamnocephalidae (six genera, sixty-two species). In Arkansas, seven anostracan species are known: Eubranchipus neglectus, E. serratus, E. moorei, Branchinecta packardi, Thamnocephalus platyurus, Streptocepalus sealii, and S. texanus. Fairy shrimps are very primitive organisms believed to have diverged during the Ordovician period from the main line of the Branchiopoda. Their fossil record dates back to the Devonian, although …

Fish

Arkansas fishes are a combination of abundant and rare species—primitive and ancestral, commercial and sport, game and non-game, native and introduced, and transplanted and exotic. There are approximately 233 fish species in Arkansas. Arkansas has a relatively rich fish fauna compared to neighboring states (which range between 148 and 319 fish species). Some species, such as the western mosquitofish (Gambusia affinis), are common statewide, whereas other species, such as the yellowcheek darter (Etheostoma moorei), have more restricted distributions. Distinct differences in topography and geology between northwestern (upland) and southeastern (lowland) Arkansas have led to distinctly different groups of fish species developing in each of these regions. For example, because of an abundance of clear, gravel-bottom, flowing streams in northwestern Arkansas, …

Fleas

Fleas are small, wingless, hematophagous (blood-feeding) ectoparasites that belong to the Phylum Arthropoda, Class Insecta, and Order Siphonaptera. There are four recognized suborders—Ceratophyllomorpha, Hystrichopsyllomorpha, Pulicomorpha, and Pygiopsyllomorpha—with about 246 recognized genera and over 2,500 described species within sixteen families. Adult fleas feed on blood of mostly mammals (about ninety-four percent of known species), including dogs, cats, and humans, with the remainder of species parasitizing birds. Fleas are an important component of the worldwide biota. In addition, they can be nuisance biters, and some serve as vectors or intermediate hosts of flea-borne disease agents and parasites. The most recent summary listed twenty-nine species of fleas in Arkansas. Fleas are most closely related, evolutionarily speaking, to insects in the orders Diptera (true …

Fourche Mountain Salamander

aka: Plethodon fourchensis
The Fourche Mountain salamander (Plethodon fourchensis) is a slender, large (115–178 millimeters in total length) terrestrial salamander that is one of twenty or so members of the caudate family Plethodontidae that can be found in Arkansas. This species is one of three endemic salamanders known to exist in Arkansas and is confined to Fourche Mountain and Irons Fork Mountain in the south-central region of the Ouachita Mountains. Normally, these salamanders can be found beneath the surface rock of hillsides and valleys within these mountains; however, they can also be found under rotting logs on the forest floor. Adults of this species possess two longitudinal rows of large, white blotches on the back; the dorsal body color is, otherwise, uniformly black. …

Freshwater Drum

aka: Grunter
aka: Gaspergou
The freshwater drum (Aplodinotus grunniens) belongs to the order Perciformes and family Sciaenidae; it is the only freshwater member of the family. Freshwater drum are endemic to freshwater environs of the Americas, and their distributional range extends as far north as the Hudson Bay of Canada and reaches as far south as the Usumacinta River Basin of Guatemala. In the United States, eastward distribution includes the eastern Appalachians westward as far as Kansas, Oklahoma, and Texas. This fish appears to have the greatest latitudinal range of any freshwater fish in North America. In Arkansas, A. grunniens occurs throughout the state but mainly is found in the larger lakes and rivers. The closest living relatives of A. grunniens are a group …

Gars

aka: Garfish
aka: Garpikes
Gars are a primitive group of euryhaline fishes dating back to the late Jurassic to early Cretaceous Period, about 150 million years ago. Gars are one of the most recognizable fishes because of their slender torpedo-shaped bodies, ganoid scales, and long snouts with numerous teeth. Dorsal and anal fins are set far back on the body, and the caudal fin is rounded, with a condition known as abbreviate-heterocercal. Gars are unusual among fishes in that their vascularized swim bladders can function as lungs; they must surface periodically to take a gulp of air. Arkansas hosts four gar species: the alligator gar (Atractosteus spatula), spotted gar (Lepisosteus oculatus), longnose gar (L. osseus), and shortnose gar (L. platostomous). Fossilized gar specimens have …

Gastrotrichs

aka: Hairybacks
The Phylum Gastrotricha (commonly called “hairybacks”) comprises about 800 species of marine, brackish, and freshwater microscopic invertebrates. Twelve genera and fewer than 100 species of freshwater gastrotrichs are known from North America. However, in North America, perhaps 75 to 90 percent of the probable diversity of freshwater gastrotrichs species are undescribed. Gastrotrichs are widely distributed cosmopolitan organisms that are divided into two orders: the Macrodasyida (with nine families), which, except for two freshwater species (Marinellina flagellata and Redudasys fornerise), are marine, and the Chaetonotida (seven families), some of which are marine, estuarine, and semi-terrestrial forms, while others are primarily found in freshwater. The Chaetonotida can be further broken down into two suborders: the Multitubulatina (Nesodasys) and the Paucitublatina (Chaetonotus, Dasydytes, …

Geckos

Geckos are lizards that belong to the Class Reptilia, Order Squamata, Suborder Sauria (Lacertilia), and Infraorder Gekkota within seven families, including Carphodactylidae (seven genera, thirty species), Diplodactylidae (twenty-five genera, 137 species), Eublepharidae (six genera, thirty species), Gekkonidae (fifty-four genera, 1,264 species), Pygopodidae (eight genera, thirty-five species), Phyllodactylidae (nine genera, 100 species), and Sphaerodactylidae (twelve genera, 200 species). By far, the true geckos (Gekkonidae) are the largest family of lizards. Many common geckos are members of this family, including dtellas (Gehyra), house geckos (Hemidactylus), true geckos (Gekko), and day geckos (Phelsuma). Geckos are cosmopolitan in distribution and are particularly species-rich in the tropics. At least one type of gecko is found in Arkansas. Geckos probably evolved in the Lower Cretaceous, and …

Goldeyes and Mooneyes

aka: Mooneyes and Goldeyes
aka: Hiodontid Fishes
North American freshwater fishes of the family Hiodontidae (order Hiodontiformes or Osteoglossiformes) include the goldeye (Hiodon alosoides) and mooneye (H. tergisus). The goldeye ranges from James Bay (bordering the provinces of Ontario and Quebec) in Canada and the Mississippi River basins from the Northwest Territory to western Pennsylvania and Ohio south to Louisiana. In Arkansas, H. alosoides is found sporadically in lakes and the larger turbid rivers of the state, including the Arkansas and Mississippi, and the smaller Black River. The mooneye (also called the “freshwater tarpon”) ranges from the St. Lawrence–Great Lakes, Mississippi River, and Hudson Bay basins from Quebec and Alberta, Canada, east to western North Carolina and south to Louisiana. In Arkansas, H. tergisus occurs in large …

Grotto Salamander

aka: Eurycea spelaea
aka: Ghost Lizard
aka: Ozark Blind Salamander
The grotto salamander (Eurycea spelaea) is a species of lungless salamander in the Phylum Chordata, Subphylum Vertebrata, Class Amphibia, Order Caudata, and Family Plethodontidae. It was originally described as Typhlotriton spelaeus but is now considered a member of the genus Eurycea. It is endemic to wet caves, sinkholes, and karst regions beneath the Springfield and Salem Plateaus of the Ozark Mountains of 120 individual sites in northern Arkansas, 124 sites in southwestern Missouri, forty-three sites in northeastern Oklahoma, and one county (Cherokee) in extreme southeastern Kansas. Its natural habitats are freshwater springs, inland karsts, and caves. It is not listed by the federal government as endangered or threatened, but it is vulnerable to changes in groundwater quality and a reduction …

Haemogregarines

Haemogregarines are protist parasites that belong to the Phylum Apicomplexa, Class Conoidasida, Order Eucoccidiorina, and Suborder Adeleorina, and include the following seven families: Adeleidae, Dactylosomatidae, Haemogregarinidae, Hepatozoidae, Karyolysidae, Klossiellidae, and Legerellidae. There are two major genera, Haemogregarina and Hepatozoon, in addition to several minor ones, including Babesiosoma, Bartazoon, Cyrilia, Dactylosoma, Desseria, Hemolivia, and Karyolysus. As a group, these parasites are cosmopolitan in their range of infected hosts (such as turtles, crocodiles, birds, reptiles, and mammals) and geographic distribution. In general, haemogregarines sensu lato (meaning, in a broad sense) are elongate to fusiform ovoidal organisms that occur within the erythrocytes (red blood cells) of various animals, mostly poikilothermic vertebrates (animals whose internal temperatures vary widely). They form a group of diverse …

Harris, Ernest James

Ernest James Harris was an accomplished entomologist known for his work on breeding Biosteres arisanus, a species of wasp that parasitizes fruit fly eggs. Thanks to the work done by Harris, B. arisanus has been bred on a large scale for the purposes of pest eradication. More than twenty nations have adopted use of the “Harris strain” of the wasp for fruit fly eradication. Harris was inducted into the Arkansas Black Hall of Fame in 1999. Ernest J. Harris was born on May 24, 1928. His parents had a farm in North Little Rock (Pulaski County), where Harris’s interest in insects first developed. After graduation, he attended Arkansas AM&N (now the University of Arkansas at Pine Bluff). There, he majored …

Harvestmen

aka: Daddy Long-Legs
aka: Granddaddy Long-Legs
Harvestmen belong to the Phylum Arthropoda, Subphylum Chelicerata, Class Arachnida, and Order Opiliones. They represent the third most diverse order in Arachnida. The order Opiliones includes five suborders as follows: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi. They are often referred to as “daddy long-legs.” They are found throughout the world (except Antarctica), and there are over 6,650 species. Their common name is derived from the fact that they are common during the harvesting season. They are traditionally akin with the Order Acari (ticks and mites) or the Novogenuata (the Scorpiones, Pseudoscorpiones, and Solifugae); however, others suggest the Opiliones forms a clade with the scorpions and two smaller orders. As such, they are considered the sister group of scorpions. In addition, …

Hemipterans

aka: True Bugs
Hemipterans, or true bugs, belong to the Phylum Arthropoda, Superclass Hexapoda, Class Insecta, Order Hemiptera, and four suborders: Auchenorrhyncha, Coleorrhyncha, Sternorrhyncha, and Heteroptera. Hemiptera is the largest order of hemimetabolous insects (those not undergoing complete metamorphosis), although male scale insects (Coccoidea) do undergo a form of complete metamorphosis. The number of species in the order is about 75,000, with a great diversity of forms, including aphids, cicadas, leafhoppers, planthoppers, and shield bugs. The three largest families of Heteroptera are Miridae (plant bugs), Lygaeidae (seed bugs), and Pentatomidae (stink bugs). The largest family, Miridae, contains major insect pests and predatory groups that can be used as biological control agents. Although hemipterans inhabit a wide variety of habitats, most are generally terrestrial, …

Herrings

aka: Clupeids
Herrings (Order Clupeiformes) belong to a large family (Clupeidae) of about 200 species within fifty-four genera of cosmopolitan ray-finned fishes that are mostly marine; a few inhabit freshwater, and some are anadromous—that is, they migrate up rivers from saltwater habitats for purposes of spawning. The family includes herrings, menhadens, sardines, and shads. Most herrings are small fishes, generally being less than 300 mm (12 in.), but some may reach 750 mm (30 in.). Many are valuable food fishes and are collected for production of fish meal and oil, protein concentrate, and fertilizer. Some commercially important species include Atlantic herring (Clupea harengus) found in the north Atlantic, Pacific sardine (Sardinops sagax), and Atlantic menhaden (Brevortia tyrannus). In the fossil record, clupeid …

Hymenoptera

aka: Ants
aka: Bees
aka: Wasps
Hymenopterans belong to the Phylum Arthropoda, Subphylum Labiata, Superclass Hexapoda, Class Insecta, and Order Hymenoptera. It is a large order of insects with over 150,000 described species comprising the sawflies, woodwasps, ichneumonids, chalcids, wasps, bees, and ants. In addition, there are over 2,000 extinct taxa. The order ranks third in the top five orders of insects in terms of total number of species. Many examples of this order are found in Arkansas, including the invasive fire ant. The Hymenoptera are divided into two suborders: the Symphyta (which have no waist) and the Apocrita (which have a narrow waist). Symphytans include the horntails, sawflies, and parasitic wood wasps. They have an unconstricted junction between the thorax and abdomen and a serrated …

Ictaluridae

aka: Catfishes
aka: Bullheads
aka: Madtoms
The Ictaluridae is a family of North American native fishes belonging to the Class Siluriformes. The Ictaluridae family also belongs to the Superorder Ostariophysi, the second-largest superorder of fish. This diverse group, present on all continents except Antarctica, contains 10,758 species—more than twenty-eight percent of known fish species in the world and seventy-two percent of all freshwater species. The family proper includes about seven genera and fifty-one species, some commonly known as bullheads, catfishes, and madtoms. As such, it is the largest family of freshwater fishes endemic to North America. In Arkansas, they are easily recognized as the only fishes in the state with four pairs (two on the snout, two on the end of maxillae, and four on the …

Insects

Insects account for over half of all species described thus far worldwide, and they are the dominant form of life in terrestrial environments. It is estimated that 35,000 to 40,000 species of insects live in Arkansas, including around 10,000 species of beetles, around 9,000 species of flies, nearly 8,000 species of bees and wasps, and around 5,000 species of moths and butterflies. The remainder make up small orders such as the bristletails, mayflies, dragonflies and damselflies, cockroaches, mantids, termites, stoneflies, grasshoppers and crickets, earwigs, stick insects, book and bark lice, chewing and sucking lice, and true bugs and lacewings and their relatives. It is still not uncommon to find species in Arkansas that are unnamed and new to the scientific …

Invasive Animals

aka: Alien Animals
An “invasive species” is defined as a species that is non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental problems or harm to human health. It typically matures and reproduces quickly and increases its geographic range rapidly, establishing populations and persisting over large areas. There are several reasons for this spread, including favorable environmental conditions and lack of natural predators, competitors, and diseases that normally regulate their populations, allowing invasive species to thrive. Invasive biota not only includes a variety of plants but also incorporates a wide variety of invertebrates and higher taxa from their native sites. As invasive species extend and dominate ecosystems, they invariably reduce native biodiversity …

Ivory-billed Woodpeckers

aka: Campephilus principalis
Long believed to be extinct, the ivory-billed woodpecker (Campephilus principalis) was apparently rediscovered in the Big Woods of east Arkansas in 2004. More than sixty years after the last confirmed sighting in the United States, a research team announced on April 28, 2005, that at least one male ivory-bill survived in the vast bottomland swamp forest. Published in the journal Science, the findings included multiple sightings of the elusive woodpecker and frame-by-frame analyses of brief video footage. The evidence was gathered during an intensive year-long search in the Cache River and White River National Wildlife Refuges in eastern Arkansas, involving more than fifty experts and field biologists working as part of the Big Woods Conservation Partnership, led by the Cornell …

James, Douglas Arthur

Douglas Arthur James served as a professor of biological sciences at the University of Arkansas (UA) in Fayetteville (Washington County) from 1953 to 2016. He was considered the authority of the birds of Arkansas, co-authoring Arkansas Birds with Joseph C. Neal in 1986, and became one of the state’s leading conservationists in the second half of the last century, helping to start the Arkansas Audubon Society in 1955 and the Arkansas Audubon Society Trust in 1972. He arranged the first meeting of what would become the Ozark Society, which was responsible for saving the Buffalo River from damming. Starting with studies of scrubland birds in northwestern Arkansas, James expanded to studying scrubland birds in Africa, Nepal, and Belize. He was …

Jumping Bristletails

aka: Archeognatha
aka: Microcoryphia
The Archaeognatha (formerly Microcoryphia) are an order of apterygotes belonging to the Superclass Hexapoda, Class Insecta, Subphylum Labiata, and Phylum Arthropoda. They are known by various common names, such as jumping bristletails. The order is cosmopolitan and includes about 500 species (thirty-three species within twelve genera are Nearctic) in two families (Machilidae and Meinertellidae). None are currently evaluated as being a conservation risk. Little is known about the archaeognaths of Arkansas, as only Machiloides banksi and Pedetontus gershneri have been reported from the state, both from Mount Magazine (Logan County). Among extant arthropod taxa, they are some of the most evolutionarily primitive insects. The fossil record of Archaeognatha is sparse and often represented by fragmentary material. They first appeared in …

Lampreys

aka: Jawless Fishes
Lampreys are primitive jawless fishes in the Family Petromyzontidae, Order Petromyzontiformes, Class Petromyzontida, and Superclass Cyclostomata. The common name “lamprey” is almost certainly derived from the Latin lampetra, which likely means “stone licker” (lambere “to lick” + petra “stone”). They are also sometimes called lamprey eels, although they are not eels. Instead, lampreys are the direct descendants of the first armored jawless fishes or ostracoderms, which first appeared over 400 million years ago during the Silurian and Devonian periods. Today, there are only two remaining groups of jawless fishes: the lampreys and the hagfishes (Order Myxiniformes, Class Myxini). Hagfishes, which resemble lampreys, are the sister taxon of lampreys based on DNA evidence. There are about forty-two living lamprey species in …

Leeches

Leeches are segmented worms belonging to the Phylum Annelida, Class Clitellata, Subclass Hirudinida. Leech classification is primarily based on the presence or absence of setae (bristles) and the morphology of the mouth, proboscis (feeding organ), jaws, and suckers. Leeches are thought to have evolved from certain oligochaete worms; however, the systematics and taxonomy of leeches are in need of review. Twenty-two species within five families (Erpobdellidae, Glossiphoniidae, Haemopidae, Hirudinidae, Piscicolidae) have been reported from northern Arkansas, but, as of 2018, there are no summaries of leeches from the southern part of the state. Leeches are bilaterally symmetrical, with thick muscular bodies. Usually, they are dorsoventrally flattened and segmented. Some leeches are long and worm-like (ranging in size from about seven …

Lice

Lice belong to the Phylum Arthropoda, Class Insecta, Order Phthiraptera, with four suborders: Anoplura (sucking lice), occurring on mammals exclusively; Rhynchophthirina, parasites of elephants and warthogs; Ischnocera, which are mostly avian lice, though one family parasitizes mammals; and Amblycera, a primitive suborder of chewing lice, widespread on birds but also infesting South American and Australasian mammals. The chewing lice (suborders Rhynchophthirina, Ischnocera, and Amblycera) were previously combined in the order Mallophaga, which did not reflect natural grouping. There are nearly 5,000 described species of lice, with about 4,000 being parasitic on birds and 800 on mammals, within about twenty-six families of described species of phthriapterans. Many mammal species can be infested by sucking lice, including seals and walruses. These “marine …

Mammals

Arkansas’s assemblage of mammals contains both domesticated and wild species, as well as humans. The agriculture and pet industries within Arkansas are enhanced by domesticated mammals. Wild mammals can be grouped into two categories: game (species with hunting seasons) and non-game (species without hunting seasons). All mammals are classified into the class Mammalia. Mammals—along with birds, fish, amphibians, and reptiles—belong to a large group known as the vertebrates (animals possessing a backbone). Mammals share common features with each other, including being homeothermic (constant internal body temperature), having hair, having mammary glands (milk-producing structures in females), and being able to give live birth. Some mammals found outside of Arkansas, such as dolphins and whales (order Cetacea), have very small amounts of …

Mantodea

aka: Mantids
aka: Mantises
Mantises belong to the Phylum Arthropoda, Class Insecta, and Order Mantodea. The order contains over 2,400 species within about 430 genera in fifteen families. The largest family is the cosmopolitan Mantidae. Mantises are distributed worldwide in mostly tropical but also temperate habitats. Little has been published on the mantises of Arkansas, although the Carolina mantid, Stagmomantis carolina, has been investigated in the central part of the state. In the fossil history of mantises, fossils of the group are rare. For example, by 2007, only about twenty-five fossil species were known. The earliest, from Siberia, are about 135 million years old. Fossil mantises, from Cretaceous amber, include a specimen from Japan with spines on the front legs, as in modern mantises. …

Mayflies

aka: Ephemeropterans
Mayflies belong to the Phylum Arthropoda, Class Insecta, and Order Ephemeroptera. They are a small, wide-ranging, primitive order of insects that is well known to entomologists, biologists, naturalists, and fly fishermen. There are approximately 3,000 species of mayflies described worldwide; these are grouped into over 400 genera within forty-two families. As of 2019, approximately 676 species within twenty-one families were recognized from North America. The southeastern United States has nearly 400 mayfly species, which is more than half of those known from the United States and almost half of those known from North America alone. No single study summarizing mayflies exists specifically for Arkansas, but an investigation from 2010 noted about 117 species of mayflies reported from the state. The …

Megaloptera

aka: Alderflies
aka: Dobsonflies
aka: Fishflies
Megaloptera is an order that is included within the Phylum Arthropoda and Class Insecta. There are about 300 extant species of megalopterans, and these include the alderflies, dobsonflies, and fishflies. There are six families: Corydalidae, Corydasialidae (extinct), Euchauliodidae (extinct), Nanosialidae (extinct), Parasialidae (extinct), and Sialidae. Megalopterans can be found in several Arkansas counties. The Megaloptera were once regarded as a part of a group of insects called Neuroptera, together with the lacewings and snakeflies; however, they are now generally considered to be separate orders, with Neuroptera only referring to the lacewings and their relatives (formerly Planipennia). The former Neuroptera, particularly the lacewing group, are very closely related to each other, and the new name for this group is Neuropterida. This …

Millipedes

There have been around 7,000 species of millipedes (sometimes spelled millipeds) described scientifically, with a projected estimate of possibly 80,000 total species occurring around the globe. Around 900 species have been described from the United States and Canada. However, the family Parajulidae, the largest group from North America, has not been studied thoroughly, suggesting that numerous more species exist in North America. Arkansas has a diverse array of millipede species. Some of them are fairly common, while others are rare. Millipedes—their name meaning “thousand feet”—make up a group of invertebrates (lacking a backbone) in the phylum Arthropoda. Within the Arthropoda phylum, millipedes belong in the subphylum Myriapoda, which includes four classes: Chilopoda (centipedes), Diplopoda (millipedes), Paurapoda (paurapods), and Sumphyla (symphylans). …

Mites

Mites are small arthropods (Phylum Arthropoda) belonging to the Class Arachnida (Subclass Acari) with two or three Superorders as follows: Acariformes (or Actinotrichida), Parasitiformes (or Anactinotrichida), and Opilioacariformes. There are four Orders, Mesostigmata, Prostigmata, Orbatida, and Astigmata. Among the more well-known mites are ticks (Ixodida). There are an estimated 48,200 species of described mites. The phylogeny of the Acari is still debatable, and several different taxonomic schemes have been proposed for their classification. The diversity of the Acari is extraordinary, and its fossil history goes back to at least the early Devonian Period (about 419 million years ago). Mites are very common in Arkansas, with chiggers being a particular pest of humans during warmer months. Historically, references to mites/chiggers go …

Moles

The mammalian family Talpidae includes seventeen genera and forty-two species of moles worldwide in the order Eulipotyphla. Of these, there are four genera and seven species in North America alone. Moles are found in most parts of North America, Asia, and Europe. The family contains all the true moles, and some of their close relatives—including desmans, but these are not normally called “moles” and belong to the subfamily Talpinae. Those species called “shrew moles” denote an intermediate form between the moles and their shrew ancestors. There are three subfamilies of moles, including the Scalopinae (New World moles) with five genera, Talpinae (Old World, desmans, and shrew moles) with nine genera, and Uropsilinae (Asian shrew-like moles) with a single genus. The …

Molluscs

aka: Mollusks
The phylum Mollusca is a major invertebrate group known commonly as “molluscs” (sometimes spelled “mollusks”), which includes about 85,000 living species (although this number varies), with another 60,000 to 100,000 additional fossil species. This phylum is ranked second only to the Phylum Arthropoda in number of living species. Included within the diverse phylum are snails, slugs, cowries, squids, clams, mussels, limpets, oysters, scallops, octopi, cuttlefish, and a myriad of additional groups such as the little-known chitons, monoplacophorans, and tusk shells. Malacology is the scientific study of molluscs, and a specialist who studies them is known as a malacologist. Two classes of molluscs inhabit Arkansas: the Gastropoda and the Bivalvia. Approximately eighty-five species of bivalves are known from the state, while …

Monogeneans

The class Monogenoidea is a fairly large group of parasitic flatworms belonging to the phylum Platyhelminthes. Monogeneans are generally found on bony fishes in freshwater and marine habitats. Although some are endoparasites in the urinary bladder and eyes, most monogeneans are ectoparasites that attach to their host’s skin or gills by a special posteriorly positioned attachment organ called a haptor. The class contains about nine orders, fifty families, and 4,000–5,000 species. The genus Dactylogyrus is one of the largest genera, with nearly 1,000 species. Some taxonomists divide the Monogenoidea into two or three subclasses based on the complexity of their haptor. Those in the subclass Monopisthocotylea have one main part to the haptor, often with hooks or a large attachment …

Mullets

aka: Gray Mullets
aka: Flathead Gray Mullets
Fishes commonly known as mullets, of the Family Mugilidae and Order Mugiliformes, are a group of more than seventy mostly marine species within some fifteen to twenty-five genera. The genus Mugil is cosmopolitan in distribution except in upper latitudes, and at least five species occur in North America. The latest evidence suggests that mullets are most closely related to atherinomorph fishes (silversides and topminnows). Although most mullets are strictly marine, the striped mullet (Mugil cephalus) has the physiological ability to travel between freshwater and salt water, spending much of its life in streams. It is a cosmopolitan resident of estuaries, temperate and tropical oceans, salt marshes, and shoreline areas along the Atlantic Coast of Nova Scotia south to Mexico and Brazil. …

Mysid Shrimps

aka: Opossum Shrimps
Mysida is an order of small, shrimp-like crustaceans in the Class Malacostraca and Superorder Peracarida, with two families, Mysidae (nine subfamilies) and Petalopthalmidae (two subfamilies); 178 genera; and 1,132 species. Most are marine species, but there are about 72 freshwater species, being predominantly found in the Palearctic and Neotropical biogeographical realms. The first report of a species of mysid shrimp documented in Arkansas was in 2012. Species within the order are found throughout the world across a broad range of habitats, such as subterranean, freshwater, and brackish. They can also be found in shallow coastal waters and in surface to deep-sea habitats. In marine waters, they can be benthic (living on the seabed) or pelagic (living in mid-water), but they …

Myxozoans

Myxozoans are a group of microscopic, oligocellular, obligate endoparasites that belong to the Phylum Cnidaria, which also includes sea anemones, box jellies, corals, true jellies, sea pens, and hydrozoans. There are two parasitic classes, the Malacosporea and Myxosporea, and more than 2,200 nominal species of myxozoans classified into sixty-four genera and seventeen families. Myxozoans were, for years, placed within their own phylum (Myxozoa). Similarities to cnidarians had been noted at various times but not firmly until 2007. Although morphological and genetic evidence support placement of the Myxozoa as cnidarians, and this taxonomy has been followed by some authorities, others have not reached the same conclusion; exactly where the Myxozoa fit in this taxonomic scheme is not yet entirely known. Less …

Nematodes

aka: Roundworms
The phylum Nematoda includes three classes (Anoplea, Chromodorea, and Rhabditida), sixteen to twenty orders, and about 27,000 described species (and possibly up to one million) of mostly dioecious, elongate, bilaterally symmetrical pseudocoelomate worms. They can be found in abundance in nearly every habitat on Earth, with a diverse array of species existing in both marine and terrestrial habitats. Most are free-living, with less than half considered to be parasitic. Nevertheless, many species threaten the health of plants and animals (including humans) on a global scale. Nematodes are variable in size from less than one millimeter to more than one meter in length. They have been in existence for an estimated one billion years, having evolved from simple animals some 400 …