Zoology

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Entries - Entry Category: Zoology - Starting with C

Caddisflies

aka: Trichopterans
Caddisflies (Phylum Arthropoda, Class Insecta, Order Trichoptera) make up the largest and most diverse group of aquatic insects. More specifically, caddisflies are a group of small to medium-sized (2 to 30 mm in length), moth-like insects with two pairs of hairy membranous wings; they have aquatic larval forms that metamorphose into terrestrial adults. The name for the order Trichoptera comes from the name Trichos, which means “hairy,” and ptera, which means “wings.” The word “caddis” dates back to The Compleat Angler, written by Izaak Walton (1594–1683) and published in 1653, in which “cod-worms or caddis” were named as being used for bait. Caddisflies are a favorite food of many fish, and therefore are attractive to anglers, particularly trout fly fishermen, …

Caddo Mountain Salamander

aka: Plethodon caddoensis
The Caddo Mountain salamander (Plethodon caddoensis) is a slender, medium-sized (90–100 millimeters in total length) terrestrial salamander. It is one of twenty or so members of the caudate family Plethodontidae that can be found in Arkansas. Adults of this species possess numerous tiny white spots and/or brassy flecks on the back and tail; the dorsal body color is otherwise uniformly black. The lateral body surfaces are creamy white in appearance. The throat region is distinctly pale or white. Juveniles may lack much of the lateral body coloration. This species is one of three endemic salamanders known to exist in Arkansas and is primarily confined to the Caddo Mountains area of the southern Ouachita National Forest and several outlying areas in …

Centipedes

Centipedes (class Chilopoda) are myriapods that include two subclasses, five living orders, and about 2,800 described species (out of an estimated worldwide fauna of approximately 8,000 species) within about twenty-three families. Their fossil history dates back over 410 million years ago to the late Silurian Period of the Paleozoic Era. In terms of worldwide geographic distribution, centipedes are found north of the Arctic Circle and inhabit all subarctic regions but are most abundant in temperate, desert, and tropical areas, where they are common terrestrial invertebrates. Humans have unintentionally introduced several species onto most oceanic islands. However, one order (Craterostigomorpha) is endemic to New Zealand and Tasmania. Members of the families Oryidae and Scutigeridae and of the subfamily Otostigminae have been …

Central Mudminnows

aka: Umbrids
The central mudminnow (Umbra limi) is a small (51 to 132 mm [2 to 5 in.]) fish that belongs to the Family Umbridae and Order Esociformes. There are three other North American members of the family: the eastern mudminnow (U. pygmaea) of the Eastern Seaboard and Atlantic Coastal Plain, the Alaska blackfish (Dallia pectoralis) that occurs in Alaska and adjacent Siberia, and the Olympic mudminnow (Novumbra hubbsi) of the Olympic Peninsula of Washington. All of these are strictly Northern Hemisphere freshwater species. A third Umbra species, the European Mudminnow (U. krameri), occurs widely throughout Europe. Mudminnows are most closely related to esocids (pikes and pickerels). The fossil record includes specimens that date back to the Oligocene of Eurasia and North …

Cestodes

aka: Tapeworms
Cestodes (tapeworms) include flatworms belonging to the phylum Platyhelminthes, class Cestoidea, subclasses Cestodaria (two orders) and Eucestoda (sixteen orders), and about fifty-nine families. The subclass Cestodaria includes monozoic (unsegmented) tapeworms containing only a single set of male and female reproductive organs; these are parasitic in the intestinal tract and body cavity of fishes and turtles. The subclass Eucestoda is made up of polyzoic (segmented) or monozoic cestodes of varying structure and parasitic in the intestines of vertebrates. To date, there are more than 5,000 described species that, as endoparasites, infect all vertebrate classes. The classification of tapeworms remains ambiguous using classical morphological studies alone, and, although some studies have been done recently using molecular tools, further attention is needed to …

Chordate Parasites

aka: Parasitic Chordates
Although the majority of the world’s parasites are protists, helminths, invertebrates, and other miscellaneous groups of organisms, parasitism has also arisen within animals of the phylum Chordata (subphylum Vertebrata). All chordates, at some time in their development, possess five derived morphological characteristics as follows: (1) a dorsal tubular or hollow nerve cord, (2) a notochord, (3) pharyngeal gill slits or pouches, (4) an endostyle, and (5) a post-anal tail. Some examples of parasitic chordates are remoras (which attach to sharks and rays); the jawless fishes (lampreys and hagfishes), which prey upon other fishes; some birds that practice brood parasitism; and vampire bats. The Superclass Agnatha has both extinct groups and extant species, including the “jawless” fish (lamprey and hagfish) that …

Cnidarians

aka: Hydroids
aka: Corals
aka: Jellyfishes
aka: Sea Anemones
Cnidarians (hydroids, jellyfishes, corals, and sea anemones) form a diverse phylum (Cnidaria, old Phylum Coelenterata) that contains more than 10,000 species. The phylum also includes the parasitic Myxozoa. Typical cnidarians inhabit aquatic (predominantly marine) environments. Cnidarians are divided into two major groups: the Anthozoa (corals, sea anemones, and sea pens), which live as sessile polyps, and the subphylum Medusozoa (Hydra, jellyfishes, and sea wasps), many of which form a free-swimming medusa as well as polyps. There are five main classes: Anthozoa, Cubozoa, Hydrozoa, Scyphozoa, and Staurozoa. Only a few cnidarians can be found in Arkansas, including a jellyfish seen in lakes and rivers. In terms of evolutionary relationships, modern molecular phylogenetic results support the notion that anthozoans represent the first …

Coccidia

aka: Apicomplexa
Coccidians are microorganisms belonging to the phylum Apicomplexa and suborder Eimeriorina, which includes eight to thirteen families, about 39 genera, and well over 2,000 species. These protists are intracellular (meaning they function inside the cell) parasites of medical and veterinary importance, including those in the genera Caryospora, Cryptosporidium, Cyclospora, Eimeria, Isospora, Sarcocystis, and Toxoplasma. Most are considered intestinal parasites that infect both invertebrates as well those animals in all vertebrate classes. These parasites cannot complete their life cycle without exploiting a host. Coccidiosis is a general term for the disease they can cause, and it is recognized as a major health concern in wild animal populations, domestic animals, and zoo animals. However, some infections appear not to cause any pathology …

Collembollans

aka: Springtails
Springtails (collembolans) belong to the phylum Arthropoda and subphylum Hexapoda. They form the largest (about thirty-five families and 9,000 different species) of the three lineages of modern hexapods that are no longer considered to be included in the class Insecta (the other two are the proturan and dipluran apterygotes). Since each has internal mouthparts, the three are sometimes grouped together into a class called Entognatha. However, they do not appear to be any more closely related to one another than they all are to insects, which have external mouthparts. Indeed, they do share some features of insects, such as a body divided into three parts, a head with antennae, a three-segmented thorax, and each segment having a pair of jointed …

Crustaceans

Crustaceans (subphylum Crustacea) are a very large and diverse group of arthropods (invertebrate animals having an exoskeleton, jointed appendages, and segmented bodies). Crustaceans are distinguished by having paired mandibular jaws and maxillae, along with two pairs of antennae. Recent classifications include six classes within crustaceans—Branchiopoda, Remipedia, Cephalocarida, Maxillopoda, Ostracoda, and Malacostraca. The Classes of Crustacea Class Branchiopoda includes several groups of primitive aquatic and marine animals, including clam shrimp, the small fairy shrimp (less than one centimeter in length and living in temporary pools), and the “living fossil” tadpole shrimp. The most noteworthy brachiopods are the cladocerans, or water fleas, that make up many of the zooplankton in Arkansas lakes and ponds. These small, free-swimming animals are a critical food …