Zoology

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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 …

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, …

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 …

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 …

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, …

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 …

Ivory-billed Woodpeckers

aka: Campephilus principalis
Long believed to be extinct, the ivory-billed woodpecker (Campephilus principalis) was 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 Laboratory …

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 …

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 …

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 …

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 …

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. …

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 …

Nematomorpha

aka: Horsehair Worms
aka: Hairworms
Horsehair worms belong to the phylum Nematomorpha and are typically obligate parasites of terrestrial arthropods (e.g., beetles, crickets, cockroaches, locusts, grasshoppers, and mantids). As adults, however, they are free-living in aquatic environments. These worms are sometimes found in coiled clusters termed “Gordian knots” from the intricate legendary knot of Greek mythology. Another myth is related to the common name given these worms, “hairworms” or “horsehair worms,” originating from the idea that horse hairs that fell into water became worms. This belief was not disproved scientifically until American anatomist and paleontologist Joseph Leidy (1823–1891) noted in 1870 that horse hairs placed in water for many months did not come to life. The first published report of a horsehair worm from Arkansas …

Nemertea

aka: Ribbon Worms
The phylum Nemertea is an invertebrate phylum that contains over 1,000 species within 250 genera of mostly marine organisms known variously as ribbon, proboscis, or nemertean worms. Only a few taxa inhabit freshwater, and there are several terrestrial species. Most are free living; however, a few are known to be parasitic. The name means one of “Nereis” (unerring one), which refers to the unerring aim of the proboscis. Ribbon worms are unique in having an eversible muscular proboscis that is used for grasping prey. It lies free inside of a cavity above the alimentary canal known as the rhynchocoel. This muscular tube can be swiftly thrust out to catch prey items. This phylum is also occasionally called the Rhynchocoela, which …

Northern Snakehead

aka: Channa argus
aka: Snakehead
The northern snakehead (Channa argus) is a modern bony fish belonging to the family Channidae. It is native to China, eastern Russia, and parts of the Korean peninsula. The fish was discovered in Arkansas in 2008, leading to attempts to eradicate it. The northern snakehead has an elongate body, with long dorsal and anal fins, and a truncated tail. Coloration is dark tan to brown with darker spots laterally, extending above and below the midline. The jaws have sharp, pointed teeth. The fish can reach a size of one meter and weigh as much as eight kilograms. The northern snakehead breathes with gills but also possesses a suprabranchial organ, which consists of chambers filled with folded tissue that allow atmospheric …

Odonates

aka: Dragonflies
aka: Damselflies
Odonates belong to the Phylum Arthropoda, Subclass Pterygota (winged insects), Class Insecta, and Order Odonata. The famous entomologist Johan Christian Fabricius (1745‒1808), who was the first to provide the name Odonata, apparently used that name because they have “teeth” on their mandibles. Odonates are considered a wide-ranging, primitive order of carnivorous aquatic insects. About 102 species have been documented in Arkansas. One of the two extant suborders of the Odonata (the order to which dragonflies and damselflies belong) is the Epiprocta. This new classification was proposed relatively recently to accommodate the inclusion of the suborder Anisozygoptera. The latter taxon has been shown not to be a natural suborder but somewhat of a paraphyletic collection of lineages, so it has been …

Official State Dinosaur

aka: Arkansas Dinosaur
aka: Arkansaurus fridayi
In August 1972, Joe B. Friday discovered the remains of the right hind foot of a dinosaur in a shallow pit on his land in Lockesburg (Sevier County). He found the bones in rocks belonging to the Lower Cretaceous Trinity Group, which consists of deposits of clay, sand, gravel, limestone, and the evaporite minerals gypsum and celestite. Friday donated the bones to the University of Arkansas (UA) in Fayetteville (Washington County), where they are kept in the University Museum Collections at the Arkansas Archeological Survey. UA professor James Harrison Quinn gave the bones the informal name “Arkansaurus fridayi” in 1973. He cleaned and assembled the bones and compared them to the feet of two similar-appearing dinosaurs previously described in the …

Opalinids

Opalinids are a small group of peculiar cosmopolitan organisms that belong to the kingdom Protista. Recent classification places the opalinids as heterotrophic stramenopiles (heterokonts) within the phylum Placidozoa, class Opalinea, and order Slopalinida. There are over 200 species, and, although opalinids are typically endocommensals (that is, living within the host without affecting it) in the large intestine and cloaca of anurans (frogs and toads), they have also been reported from fish, salamanders, reptiles, and some invertebrates (mollusks and insects). They are of no medical or economic importance, but they are interesting because their reproductive cycles are apparently controlled by the host’s hormones. In addition, opalinids are routinely encountered in dissections of frogs in college biology laboratories, and most students are …

Opossums

aka: Possums
aka: Didelphis virginiana
Arkansas opossums (commonly referred to as “possums”) are of the Virginia opossum species Didelphis virginiana and can be found in both rural and urban habitats. The Arkansas Game and Fish Commission tracks opossum populations and oversees an opossum hunting season during the winter months. As the only marsupials found in North America, opossums have existed for 70–80 million years. They are highly adaptable omnivores who eat a variety of foods including insects, rodents, berries, grasses, leaves, and carrion. The females can have twenty to twenty-five babies in one litter and carry their young in their pouches for up to three months. Opossums have opposable thumbs on their rear feet and can also grasp with their tails. Contrary to popular belief, …

Ostracods

aka: Seed Shrimps
aka: Mussel Shrimps
Ostracods belong to the Class Ostracoda within the Subphylum Crustacea and Phylum Arthropoda. Commonly called “seed or mussel shrimps,” the class encompasses over 33,000 described species and subspecies, and many more remain unknown to science and await formal description. There are two subclasses with living representatives: the Myodocopa and Podocopa. The former is exclusive to marine environments but occupies the benthos as well as the plankton, whereas podocopans occur in marine, brackish, and freshwater environments and occupy almost exclusively the benthos (but also the benthopelagic zone). The main orders are the Archaeocopida, Leperditicopida, Palaeocopida, Podocopida, and Myodocopida. As of 2019, there is no comprehensive list of extant ostracods in Arkansas. Ostracods are important fossil organisms, as they are the most …

Ozark Cavefish

aka: Amblyopsis rosae
The Ozark cavefish (Amblyopsis rosae) is found in the Springfield Plateau of the Ozark Mountains. Its geographic distribution covers approximately 8,200 square miles (21,000 square kilometers), comprising an area drained by the White River on the south and the east, the Neosho River (Arkansas River basin) on the west, and the Osage River (Missouri River basin) to the north. This species has been reported in at least fifty-two caves over three states: Missouri, Arkansas (originally in ten but now in seven sites in Benton County), and northeast Oklahoma. It has been proposed that there are two subspecies of this fish: Amblyopsis rosae whitae for the White River drainage region and Amblyopsis rosae arkansasus for the middle Arkansas River drainage region. …

Ozark Hellbender

aka: Cryptobranchus alleganiensis bishopi
The salamander called the Ozark hellbender (Cryptobranchus alleganiensis bishopi) is one of two subspecies of hellbender (Cryptobranchus alleganiensis). Historically, the eastern hellbender (C.a. alleganiensis) is found throughout much of the upland areas of the United States east of the Mississippi River; it also inhabits northern portions of the Ozark Mountains of Missouri. The Ozark hellbender occurs in several southern-flowing streams of the Ozark Mountains of Missouri and has a very restricted range in Arkansas, occurring only in the upper reaches of the Spring River, in portions of the Eleven Point River in Randolph County, and in the White River at Batesville (Independence County) and near the town of Norfork (Baxter County). The hellbender, North America’s largest salamander, sometimes grows to …

Ozark Pocket Gopher

aka: Geomys bursarius ozarkensis
The Ozark pocket gopher is a small mammal that belongs to the family Geomyidae (pocket gophers) and the order Rodentia (rodents). It is endemic to Arkansas, occurring in Izard County. The common name “pocket gopher” comes from the fur-lined cheek pouches that these animals use to carry food. Two species of pocket gophers live in Arkansas. Geomys bursarius can be found from southern Manitoba southward through the central plains of the United States toward Arkansas and Texas, with the subspecies G. b. ozarkensis found in the southwestern one-third of Izard County in Arkansas. Although a few individuals have been captured on the southern side of the White River in adjacent Stone County, no current population resides in any other county …

Paddlefish

aka: Spoonbill Catfish
Paddlefish belong to the family Polyodontidae and order Acipensiformes. There are six known species—four are extinct (three from western North America, one from China) and known only from fossil remains, while two extant species include the paddlefish (Polyodon spathula), which is native to the Mississippi River basin in the United States, and the gigantic critically endangered Chinese paddlefish (Psephurus gladius) endemic to the Yangtze River Basin in China, where they lived primarily in the broad-surfaced main stem rivers and shoal zones along the East China Sea. Paddlefish are basal Chondrostean ray-finned fish; they are archaic and have been referred to as “primitive fish” because they have evolved with few unique morphological changes since the earliest fossil records of the late …

Parasitic Crustaceans

The Subphylum Crustacea (Phylum Arthropoda) represents a diverse group of animals with members within several classes and orders, including the Amphipoda, Branchiura, Cirripedia, Copepoda, Isopoda, and Tantulocarida. (The Pentastomida, composed of parasites, are sometimes included in this subphylum and sometimes considered a separate phylum.) There are two classes with parasites: the Maxillopoda and Malacostraca. The majority of crustaceans are aquatic, living in either marine environments or fresh water, but a few groups have adapted to a terrestrial existence, such as some species of crabs and woodlice. Most crustaceans move about independently and live a free existence, although some are parasitic (about 30,000 named species) and live attached as ectoparasites to their hosts, including fish, sea, and whale lice, as well …

Passenger Pigeons

aka: Ectopistes migratorius
The passenger pigeon (Ectopistes migratorius) was a North American bird species in the order Columbiformes (pigeons and doves) that became extinct in the early twentieth century. The fate of the passenger pigeon serves as a graphic lesson in the misuse of natural resources, as the species went from an almost indescribable abundance to extinction in only a few decades. The decline came primarily as a result of relentless persecution of its breeding colonies by market hunters, largely for meat, with no (or ineffectual) regulation that might have maintained a stable population. The passenger pigeon had the same general body shape as the common and familiar mourning dove (Zenaida macroura) but was larger and somewhat more colorful, with areas of slate-blue …

Pentastomes

aka: Tongue Worms
The phylum Pentastomida (some consider it a class) includes four orders, seven families, and about 144 species, including eight extinct species from the Paleozoic Era. They are wormlike obligate parasites, meaning that they cannot complete their life cycle without a host. As adults, they inhabit the respiratory tract (lungs and nasal passages) of vertebrates. Four species are known from intermediate host insects (three coprophagus cockroaches and one coleopteran). In addition, fishes are common intermediate hosts for pentastomes occurring in crocodilians and piscivorous chelonians, and rarely for some species of snakes. Definitive hosts include amphibians (few hosts) but mainly reptiles (lizards, snakes, freshwater turtles, and crocodilians), the latter making up about seventy percent of hosts. The most common genera of reptilian …

Percidae

The Percidae is a family containing three subfamilies and approximately 250 species within eleven genera of perciform fishes found mostly in freshwater and brackish waters of the Northern Hemisphere. Most are found in the Nearctic realm. It is one of the largest families in North America, making up about one-fifth of all fish biota, only outnumbered by the Cyprinidae. There are also some Palearctic (Eurasian) species in the genera Gymnocephalus (four species), Percarina (two species), Romanichthys (single species), and Zingel (four species). The family includes the perches and their relatives, with some well-known species such as the ruffe, sauger, walleye, and three species of perch. However, much smaller fishes restricted to North America known as darters are also an integral …

Pillstrom Tongs

Pillstrom Tongs were invented by Lawrence G. Pillstrom MD for the safe capture of snakes for scientific research. The company eventually began shipping these unique, safe herpetological tools all over the world. They are used by zoos, animal control agencies, specialty animal handlers, collectors, and others. The company expanded upon the line of original snake tongs and modified them to be used for hunting frogs, pruning trees, cooking outdoors, picking up aluminum cans, and more. In 1953, as a young student at what is now the University of Arkansas for Medical Sciences (UAMS) in Little Rock (Pulaski County), Pillstrom began some early studies and medical research of snake venom and its effects. As a key part of his doctoral work, …

Pirate Perch

The pirate perch (Aphredoderus sayanus) belongs to the order Aphredoderiformes (or by some sources, Percopsiformes) and family Aphredoderidae. There are two subspecies, A. s. sayanus and A. s. gibbosus. It is the only living member of the family and ranges from the Atlantic and Gulf slopes from Michigan, Wisconsin, Minnesota, and New York south to the Gulf of Mexico and west to the Brazos River drainage, Texas. In Arkansas, A. sayanus occurs throughout the Coastal Plain physiographic region extending westward into the central areas of the state. It is quite rare in the Ozark uplands, and there are no records from the northwestern part of the state. The Aphredoderidae contains one fossil genus, Trichophanes, with possibly two of three valid …

Planarians

aka: Triclads
There are at least seven species of planarians found in Arkansas, on land and in water. Planarians belong to the superphylum Lophotrochozoa, phylum Platyhelminthes, subphylum Catenulidea, class Rhabditophora (some consider the artificial grouping Turbellaria), order Tricladida, suborder Paludicola, and families Dugesiidae, Kenkiidae, Planariidae, and Dendrocoelidae. These flatworms are often simply referred to as triclads or triclad worms. Currently, the order Tricladida is split into three suborders, including the marine forms (Maricola); those found mostly in freshwater habitats of caves, although at least one species occurs in surface waters (Cavernicola); and land planarians/freshwater triclads (Continenticola). Scientists have argued about the systematics of platyhelminths for many years, and with the advent of molecular approaches (18S and 28S ribosomal DNA sequences), older classification …

Proturans

aka: Coneheads
Proturans belong to the Phylum Euarthropoda, Class Entognatha, and Class Protura. The Protura constitute a taxon of hexapods that were previously thought to be insects and now are considered as a class on their own. Proturans are cosmopolitan in distribution (except for both polar regions and snow zones of mountains) with more than 800 described species belonging to three distinct orders (Acerentomata, Eosentomata, and Sinentomata) and seven families (Acerentomidae, Antelientomidae Eosentomidae, Fujientomidae, Hesperentomidae, Protentomidae, and Sinentomidae). As of 2019, seventy-six genera are known worldwide, with nearly 300 species contained within the single cosmopolitan genus, Eosentomon. There are about twenty-six species in North America, though there is no exact number of species reported, to date, from Arkansas. However, four species of …

Razorback Hogs

Arkansas was known for its razorback hogs long before the University of Arkansas mascot came into being. These wild boars were called razorbacks because of their high, hair-covered backbone and ill-mannered temper. The razorback hog was considered ruthless and dangerous when backed into a corner. The true wild boar, also called the European or Russian boar, is not native to the United States. Christopher Columbus introduced their domesticated ancestors to the New World in 1493. Wild boars are thought to have arrived with explorer Hernando de Soto, who brought the original thirteen grunting hogs to the new world in 1539, though this theory has lately been cast into doubt by Charles Hudson, who reconstructs de Soto’s path in his book, …

Red-cockaded Woodpeckers

aka: Picoides borealis
With the exception of the recently rediscovered ivory-billed woodpecker, red-cockaded woodpeckers (Picoides borealis) are the rarest of Arkansas’s nesting woodpeckers. A century ago, the bird was common in mature, open pine stands. Its natural range included millions of acres of pine habitat throughout the southeast United States. An estimated ninety-nine percent of suitable habitat was lost because of logging, wildfire suppression, conversion to agricultural lands, and urbanization. Best estimates range-wide indicate an original population numbering over four million. By the time the bird was declared endangered, it had declined to an estimated 10,000. The Arkansas population dwindled to under 400 birds. The red-cockaded woodpecker was designated as endangered on October 13, 1970. It received formal legal protection with the passage …