Entry Category: Science and Technology - Starting with C

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 …

Cyprinids

The Cyprinidae is a diverse family of mainly freshwater fishes belonging to the ostariophysian order Cypriniformes, collectively called cyprinids. They include carps, true minnows, and their relatives. The Cyprinidae is the largest and most diverse fish family and, in general, the largest vertebrate animal family, with about 3,160 species, of which only 1,270 are extant, divided into about 376 genera. The family occurs in Africa, Eurasia, and North America (northern Canada to southern Mexico). Only two species of cyprinids occur in true marine waters, daces (Tribolodon brandtii and T. sachalinensis) from eastern Asia, and a few stray into brackish water only very rarely. More than sixty-two species of cyprinids are known from Arkansas, which represents almost a third of the …