Image
from article Forest ecosystem
Forest in Moran State Park on Orcas Island, Washington. (Credit: Chris Willig)
Search Results
Search Results
Refine this search
Search result paging links
2,465 results
Image
from article Forest ecosystem
Forest fire in No Name Creek area of Colorado. (Credit: Andrea Booher/FEMA)
Image
from article Forest ecosystem
Puma and cub in forest. (Credit: Grant Faint/Stockbyte/Getty Images)
Image
from article Forest ecosystem
Conceptual model of elemental cycling in a terrestial ecosystem, emphasizing the presence and activities of arthropod consumers. The indirect regulation of elemental movement by arthropods is indicated by the hourglass-shaped valves on these flows.…
Image
from article Forest ecosystem
The southern pine beetle (Dendroctonus frontalis) is a destructive insect pest of coniferous forests in the southern United States. (Credit: U.S. Forest Service)
Image
from article Forest ecosystem
Belowground food web. (Credit: Elaine Ingham)
Image
from article Vampyromorpha
Vampyroteuthis infernalis (vampire squid) living in the oxygen-minimum zone of Monterey Bay, California, at depths of 600–900 m (1970–2950 ft). (Photo courtesy of Kim Reisenbichler, Monterey Bay Aquarium Research Institute, Moss Landing, CA)
Image
from article Vampyromorpha
Vampyroteuthis infernalis (vampire squid) showing sensory filaments and photophores (light organs).
Image
from article Civet
Owston's palm civet (Chrotogale owston). (Photo copyright © by Mark Kostich)
Image
from article Patellogastropoda
Whitecap limpet (Acmaea mitra). (Photo by Douglas Eernisse)
Image
from article Patellogastropoda
Ribbed Mediterranean limpet (Patella ferruginea). (Photo by Georgina Rivera Ingraham)
Image
from article Patellogastropoda
Radula of the patellogastropod Notoacmea scapha.
Image
from article Bicosoecida
A bicosoecid, Codomonas annulata.
Image
from article Rhizocephala
Loxothylacus texanus (arrow) attached to the abdomen of the blue crab (Callinectes sapidus). (After E. G. Reinhard, Parasitic castration of Callinectes, Exp. Parasitol., 5:79–107, 1956)
Image
from article Polychaeta
Examples of polychaetes. (a) Platynereis dumerilii antipoda. (b) Branchiomma sp. (c) Arenicola bombayensi. (After P. L. Beesley et al., 2000)
Image
from article Polychaeta
Platynereis dumerilii antipoda, showing the antero-dorsal end with the pharynx everted. (After P. L. Beesley et al., 2000)
Image
from article Polychaeta
Hololepidella laingensis; scanning electron microscope view of the anterior end with the pharynx everted. An: antennae; Pa: palps; Prb: proboscis; Prs: prostomium; TeC: tentacular cirrus. Numbers refer to the segments of the trunk. Magnification,…
Image
from article Polychaeta
Gastrolepidia clavigera; scanning electron microscope view of the anterior end. Mo: mouth; Ja: jaw; Pa: palps; Prb: proboscis. Magnification, 30×.
Image
from article Polychaeta
Gastrolepidia clavigera, scanning electron microscope view of the two first parapodia (Pa1, Pa2). Ch: chaetae; Ci: cirrus; Nop: notopodium; Nep: neuropodium. Magnification, 40×.
Image
from article Polychaeta
Section through a polychaete. (After E. E. Ruppert and R. D. Barnes, Invertebrate Zoology, Saunders College Publishing, Orlando, 1994)
Image
from article Chaetonotida
Marine gastrotrichs of the order Chaetonotida; dorsal views. (a) Xenotrichula (courtesy of W. D. Hummon). (b) Chaetonotus (after W. D. Hummon, Intertidal marine Gastrotricha from Colombia, Bull. Mar. Sci., 24:396–408, 1974).
Image
from article Skink
Five-lined skink (Plestiodon fasciatus; formerly Eumeces fasciatus). (Credit: George W. Robinson; copyright © California Academy of Sciences)
Image
from article Ephemeroptera
Ephemeroptera. (a) Mayfly, adult male, Hexagenia sp., in usual resting position (after A. H. Morgan, Field Book of Ponds and Streams, G. Putnam's Sons, 1930). (b) Mayfly, subadult male, Callibaetis sp., newly emerged from water, standing on surface…
Image
from article Prairie dog
Black-tailed prairie dogs (Cynomys ludovicianus). (Photo by Ron Singer, U.S. Fish and Wildlife Service)
Image
from article Percopsiformes
Trout-perch (Percopsis omiscomaycus). (Photo by Konrad P. Schmidt)
Image
from article Percopsiformes
Pirate perch (Aphredoderus sayanus). (Photo by Konrad P. Schmidt)
Image
from article Percopsiformes
Ozark cavefish (Amblyopsis rosae). (Photo courtesy of U.S. Fish and Wildlife Service)
Image
from article Prosobranchia
Common gastropods. (Top left) Murex troscheli. (Middle) Conus gloriamaris. (Top right) Lambis crocata. (Bottom) Angaria vicdani.
Image
from article Sauropterygia
Ceresiosaurus calcagnii, ventral view.
Image
from article Zebu
Gray Brahman bull (Bos indicus). (Photo courtesy of Salinas Ranch, Carmine, Texas)
Image
from article Desertification
Overgrazing on North American rangelands contributes to soil compaction and alters the composition of vegetation. (Credit: Thomas Wikle)
Image
from article Desertification
Desertification can be accelerated by cultivation in areas better suited for herding, such as this field in Ethiopia. (Credit: Thomas Wikle)
Image
from article Desertification
Grazing animals have contributed to desertification in Africa’s Sahel region. (Credit: Thomas Wikle)
Image
from article Laminariales
Laminaria: (a) sporophyte; (b) cross section of blade, showing a sorus of unilocular sporangia interspersed with sterile hairs (paraphyses); (c) zoospore; (d) male gametophyte with antheridia; (e) antherozoid (sperm); (f) female gametophyte with…
Image
from article Laminariales
Giant kelp (Macrocystis pyrifera) can grow up to 0.6 m (2 ft) per day. Note the series of frond blades, with each subtended by a bladder. (Photo courtesy of Charlotte Stevenson, University of Southern California Sea Grant, Los Angeles)
Image
from article Diadematoida
Two ambulacral plates of Diadema. (After T. Mortensen, A Monograph of the Echinoidea, III, C. A. Reitzel, Copenhagen, 1943)
Image
from article Diadematoida
Diadema antillarum on coral reef. Spines are commonly black, but white spines, as shown here, are also frequently found. (Photo courtesy of J. E. Miller)
Image
from article Valvatida
Valvatid pedicellariae (valvate type) on marginal plates of Hippasteria trojana.
Image
from article Valvatida
Three-dimensional diagram showing the main ossicles of the valvatid arm.
Image
from article Remipedia
Representative Remipedia. (a) Speleonectes lucayensis (after F. R. Schram, Crustacea, Oxford University Press, New York, 1986). (b) Lasionectes entrichoma [after J. Yager and F. R. Schram, Lasionectes entrichoma, new genus, new species (Crustacea:…
Image
from article Cumacea
A typical adult male cumacean.
Image
from article Coronoidea
Stephanocrinus gemmiformis, Middle Silurian, Tennessee; side view of the theca.
Image
from article Macrostomorpha
Macrostomum lignano, a new species from the northern Adriatic near Lignano, Italy. (a) Photomicrograph of a living, slightly squeezed worm. (b) Diagram showing the major organ systems. (From L. Schärer, G. Joss, and P. Sandner, Mating behavior of…
Image
from article Myzostomida
Scanning electron microscopy view of the ventral side of the Indo-Pacific Myzostoma ambiguum showing the parapodia and the marginal cirri. The individual is 4 mm (0.16 in.) long.
Image
from article Myzostomida
Scanning electron microscopy view of the ventral side of the Atlantic Myzostoma cirriferum metatrochophore. The larva is 0.05 mm (0.002 in.) long.
Image
from article Alpine vegetation
A windswept and stunted whitebark pine (Pinus albicaulis) growing among the alpine vegetation on Mount Washburn in Yellowstone National Park, Wyoming, United States. (Credit: R. G. Johnsson)
Image
from article Alpine vegetation
Alpine vegetation and flowers blooming in Mount Rainier National Park in Washington, United States. (Credit: National Park Service)
Image
from article Killer whale
Killer whales (Orcinus orca) in the waters off Alaska. (Credit: David Ellifrit/Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration)
Image
from article Killer whale
The tail of a killer whale. (Credit: Janice Waite/Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration)
Image
from article Paleopathology
The fused spine and ribs in a case of ankylosing spondylitis from an adult male human found at a burial site near the Kuskokwim River, Alaska. (Credit: Department of Anthropology, National Museum of Natural History, Smithsonian Institution Catalog…
Image
from article Paleopathology
Pottery figurine of an achondroplastic dwarf from an archeological site in Tachina, Esmeraldas, Ecuador, dated between 500 BCE and 500 CE. (Credit: Department of Anthropology, National Museum of Natural History, Smithsonian Institution Catalog No.…
Image
from article Paleopathology
Sword trauma that removed part of the left upper jaw and the right lower jaw so that no remaining teeth were in contact between the jaws. The adult male human survived this injury. The skull is from an archeological burial site near the Stewart…
Image
from article Paleopathology
Destruction of the lower portion of the fourth lumbar vertebra (arrow), probably caused by tuberculosis, from a young male human skeleton found at the archeological burial site of Bâb edh-Dhrâ in Jordan, dated to approximately 3300 BCE. (Credit:…
Image
from article Paleopathology
The effect of scurvy on the right side of the cranium of an 11-year-old human child from the archeological site of Pachacamac, Peru. (Credit: Department of Anthropology, National Museum of Natural History, Smithsonian Institution Catalog No. 266599)
Image
from article Grylloblattodea
Dorsal view of the first ice crawler species to be described: Grylloblatta campodeiformis. (Redrawn from the original paper by E. M. Walker, A new species of Orthoptera, forming a new genus and family, Can. Entomol., 46(3):93–99, 1914)
Image
from article Mink
American mink (Neovison vison; alternatively, Mustela vison). (Photo courtesy of Isle Royale National Park, Michigan; U.S. National Park Service)
Image
from article Sarcopterygii
Marbled or speckle-bellied lungfish (Protopterus aethiopicus). This African lungfish, a member of the class Sarcopterygii, can reach up to 2 m (6.6 ft) in length. (Photo by Joel Abroad)
Image
from article Cryptomonadida
Examples of cryptomonads. (a) Chilomonas paramecium. (b) Cryptomonas erosa.
Image
from article Porcupine
North American porcupine (Erethizon dorsatum). (Photo from National Park Service)
Image
from article Neandertal DNA
The geographical range within which Neandertal remains have been found (dashed line). White dots show the sites of the discoveries used to estimate the almost-complete hypervariable segment I (HVS-I) sequence of the Neandertal mtDNA. The approximate…
Image
from article Neandertal DNA
The mtDNA hypervariable segment I (HVS-I) diversity found in eight Neandertals. The nucleotide substitutions and insertions relative to the Cambridge Reference Sequence (CRS) are shaded. (Credit: Igor Ovchinnikov and William Goodwin)
Image
from article Neandertal DNA
Phylogenetic analysis of the Neandertal mtDNA hypervariable segment I (HVS-I) sequence. (a) Neighbor-joining tree of the Neandertal mtDNA sequences and 2500 modern human HVS-I sequences from 43 modern populations. (b) Neighbor-joining tree of the…
Image
from article Grassland ecosystem
Grasslands cover the Great Plains region in North America, extending from southern Texas into Canada. (Credit: U.S. Forest Service)
Image
from article Grassland ecosystem
Map of grassland types in central and western North America. (Copyright © McGraw Hill)
Image
from article Xiphosurida
Segmentation of Limulus polyphemus. Inconclusive evidence indicates that there are 15 segments (6 in the prosoma, 9 in the opisthosoma). The telson (XV) may be a terminal spine that has become articulated and has incorporated the anus into its base.…
Image
from article Xiphosurida
Phylogeny and representative species of the order Xiphosura, including the suborder Xiphosurida and its sister group, synziphosurines (a paraphyletic stem group). (Copyright © McGraw Hill)
Image
from article Xiphosurida
Paleolimulus signatus, a limuline xiphosurid from the Permian of Kansas, showing appendages and book gills. Length of specimen: 1.25 cm (0.5 in.). (Copyright © McGraw Hill)
Image
from article Xiphosurida
Carapaces of adult male horseshoe crabs: (a) Limulus polyphemus; (b) Tachypleus tridentatus; (c) Carcinoscorpius rotundicauda. (Copyright © McGraw Hill)
Image
from article Xiphosurida
Embryonic and larval development of Limulus polyphemus. (a) Early embryo, side view. (b) Late embryo. (c) Yolk-filled digestive tract of larva. Note the segmentation of yolk in the newly hatched stage and the six lobes of digestive gland. (d) First…
Image
from article Xiphosurida
Morphology of adult male Limulus polyphemus. (a) Dorsal view. (b) Ventral view, appendages not shown. (c) Cross section through prosoma showing internal anatomy. (d) Posterior view. (e) Lateral view. (Copyright © McGraw Hill)
Image
from article Feather
Typical flight feather. (a) Full view. (b) Detail of base. (c) Detail of vane. (After J. Van Tyne and A. J. Berger, Fundamentals of Ornithology, 2d ed., John Wiley and Sons, 1976)
Image
from article Feather
Parts of three barbs from a vaned feather, showing the hooking mechanism of the overlapping barbules. (After J. C. Welty, The Life of Birds, Saunders, 1962)
Image
from article Feather
Types of feathers, (a) Filoplume. (b) Vane or contour. (c) Down. (d) Semiplume. (After J. C. Welty, The Life of Birds, Saunders, 1962)
Image
from article Feather
Section through growing feather follicle. (After R. I. C. Spearman, The keratinization of epidermal scales, feathers, and hairs, Biol. Rev., 41:59–69, 1966)
Image
from article Water conservation
Drying lake because of drought. (Credit: Tim McCabe/USDA Natural Resources Conservation Service)
Image
from article Mammoth
Skeleton of a mammoth (genus Mammuthus). (Credit: Beatrissa/Shutterstock)
Image
from article Mammoth
Photograph of the grinding surfaces of a molar tooth of an adult Mammuthus columbi (main image) and a tooth from a baby mammoth (lower-left image). Cross ridges of enamel show various stages of wear, with dentine in the middle of each pair of…
Image
from article Mammoth
View of a sculpture of a mammoth at the La Brea Tar Pits and Museum in Los Angeles, California. (Credit: Zack Frank/Shutterstock)
Image
from article Mammoth
Pictographs of a mammoth and a bison at a site along the San Juan River in Utah: (top) photo without enhancement; (bottom) labeled photo with colorized mammoth and bison. (Credit: Ekkehart Malotki)
Image
from article Population dispersion
Uniform distribution of a mature population of creosote bushes (Larrea tridentata). (Credit: Evelyn Jo Johnson)
Image
from article Population dispersion
Basic patterns of the dispersion of individuals in a population: (left) random; (middle) uniform; (right) clumped (but groups are random). (Copyright © McGraw Hill)
Image
from article Pseudoscorpionida
An unidentified pseudoscorpion species of the family Atemnidae. (Photo copyright © Gonzalo Giribet)
Image
from article Pseudoscorpionida
Synsphyronus apimelus, a pseudoscorpion belonging to the family Garypidae. (Photo copyright © Gonzalo Giribet)
Image
from article Pseudoscorpionida
Pseudoscorpion morphology. (a) Adult, in two views. (b) Chelicera of a male pseudoscorpion. (Illustration based on an original by H. S. Pratt)
Image
from article Orthida
Orthida: (a) dorsal, (b) ventral, (c) posterior, and (d) anterior views of Platystrophia, Ordovician; (e) diversity history of orthid families. (a–d after R. C. Moore, C. G. Lalicker, and A. G. Fischer, Invertebrate Fossils, McGraw-Hill, New York,…
Image
from article Eumalacostraca
Phylogeny of the Eumalacostraca. (a) Based on the caridoid facies concept (after F. Schram, ed., Crustacean Phylogeny, Crustacean Issues, A. A. Balkema NE, vol. 1, 1983). (b) Based on general morphological characters (after F. R. Schram, Crustacea,…
Image
from article Zebra
Grevy's zebra (Equus grevyi), Samburu National Reserve, Kenya. (Credit: Gerald and Buff Corsi; copyright © California Academy of Sciences)
Image
from article Bioeroding sponges
Growth forms of bioeroding sponges. (a) Alpha form. Fistules of Aka mucosa (Phloeodictyidae) breaking through the surface of a live coral. (b) Alpha form. Cliona celata papillae (Clionaidae). Sievelike inhalant papillae, four open exhalant papillae…
Image
from article Bioeroding sponges
Sponge bioerosion. (a) Cross section through a colony of Cliona celata in coral. Gray areas are bioerosion chambers filled with sponge tissue and pin-shaped skeletal elements. The latter are arranged in pallisade in the two papillae that break…
Image
from article Coati
South American or ring-tailed coati (Nasua nasua). (Photo copyright © Lisa Kostich)
Image
from article Raphidioptera
A female snakefly (Raphidiidae: Turcoraphidia amara) showing the raised elongate neck and head and the long ovipositor. (Photo courtesy of P. Sehnal)
Image
from article Raphidioptera
A male snakefly [Inocelliidae: Fibla (Reisserella) pasiphae] showing the loose venation and the pterostigma. (Photo courtesy of H. Aspöck)
Image
from article Raphidioptera
A larva of a snakefly [Raphidiidae: Phaeostigma (Graecoraphidia) divina]. (Photo courtesy of F. Anderle)
Image
from article Raphidioptera
A pupa of a snakefly (Raphidia ariadnae). (Photo courtesy of F. Anderle)
Image
from article Raphidioptera
Distribution of the insect order Raphidioptera, with approximately 230 species.
Image
from article Conifer
A mixed conifer forest primarily composed of western white pine and mountain hemlock surrounding Cliff Lake, Lassen Volcanic National Park, California. (Credit: Amanda Sweeney/National Park Service)
Image
from article Conifer
Conifers dominate the boreal forests (taigas) of Denali National Park and Preserve in Alaska. (Credit: Holly Hildreth; copyright © McGraw Hill)
Image
from article Conifer
Conifer seed cone structure. (a) Pine cone consisting of seed scales attached to the cone axis immediately above the bracts. One scale is bent back to reveal two seeds attached to the upper surface. (b) Fertile shoot from above a bract in an Emporia…
Image
from article Cyclostomatida
Cyclostome zooids (order Cyclostomatida) with tentacles retracted versus extended. (Reprinted with permission from R. J. Cuffey and J. E. Utgaard, Bryozoans, pp. 201–216, in R. Singer, ed., Encyclopedia of Paleontology, Vol. 1, 2d ed., Fitzroy…
Image
from article Xenoturbellida
Photograph of a live specimen of Xenoturbella [1–2 cm (0.4–0.8 in.)], showing the sensory circumferential groove around its middle.
