This Document Contains Chapters 17 to 18 Chapter 17--The Open Sea 1. In tropical water, the photic zone in the open ocean can extend down to: A. 10 m. B. 20 m. C. 100 m. D. 200 m. E. 1000 m. Answer: D. 200 m. 2. The epipelagic refers to the location of pelagic animals that can extend down to: A. 10 m. B. 20 m. C. 100 m. D. 200 m. E. 1000 m. Answer: D. 200 m. 3. Pelagic organisms live: A. in the water column. B. on the sediment. C. in the sediment. D. in hydrothermal vents. E. close to shore. Answer: A. in the water column. 4. Those organisms that can swim strongly against ocean currents are called: A. plankton. B. neuston. C. nekton. D. macroplankton. E. epifauna. Answer: C. nekton. 5. Those organisms that cannot swim against the ocean currents are collectively called: A. plankton. B. nekton. C. seston. D. demersal. E. infauna. Answer: A. plankton. 6. All the following are used to classify plankton except: A. taxonomic groups. B. functional groups. C. life history. D. light spectrum requirements. E. size. Answer: D. light spectrum requirements. 7. Phytoplankton of the open ocean are very small in order to: A. avoid detection by grazers. B. maximize their surface area. C. increase their sinking rates. D. None of these. E. All of these. Answer: B. maximize their surface area. 8. The most abundant plankton are the: A. phytoplankton. B. bacterioplankton. C. viriplankton. D. zooplankton. E. macroplankton. Answer: C. viriplankton. 9. Archaeans and bacteria are generally included in the: A. seston. B. tripton. C. bacterioplankton. D. viriplankton. E. pleuston. Answer: C. bacterioplankton. 10. The base of the food web in the open ocean and the bottom beneath the open ocean is: A. algae. B. seagrasses. C. chemosynthetic bacteria. D. phytoplankton. E. detritus. Answer: D. phytoplankton. 11. Primary productivity is limited in surface waters of the open ocean by: A. sunlight. B. nutrients. C. carbon dioxide. D. oxygen. E. temperature. Answer: B. nutrients. 12. The dominant primary producers in tropical open ocean areas are: A. large net phytoplankton. B. small nanoplankton. C. diatoms. D. algae. E. seaweeds. Answer: B. small nanoplankton. 13. Kinetic organisms can move themselves by all except: A. flagella. B. jet propulsion. C. undulation of the body. D. using turbulent mixing. E. None of these. Answer: D. using turbulent mixing. 14. Particles suspended in the sea are called: A. seston. B. tripton. C. bacterioplankton. D. viriplankton. E. nekton. Answer: A. seston. 15. Marine snow is composed of: A. inorganic nutrients. B. flocculated marine salts. C. particulate organic matter. D. frozen seawater. E. terrestrial materials. Answer: C. particulate organic matter. 16. Marine snow refers to: A. neston. B. seston. C. cobwebby aggregates of mucus. D. fecal pellets. E. necktonic organisms. Answer: C. cobwebby aggregates of mucus. 17. Phytoplankton patchiness in the epipelagic can occur when: A. water clarity declines. B. there is an influx of nutrients. C. surface waters plunge to depths. D. fish aggregate. E. hydrothermal vents erupt. Answer: B. there is an influx of nutrients. 18. Macroplankton are organisms visible to the naked eye and generally exceed _______________ in size. A. 5 mm B. 1 mm C. 5 mm D. 10 mm E. 10 cm Answer: B. 1 mm 19. Plankton that can be caught with a standard plankton net are called: A. nanoplankton. B. picoplankton. C. microplankton. D. megaplankton. E. gigaplankton. Answer: C. microplankton. 20. An example of megaplankton would be: A. larval fishes. B. Sargassum seaweed. C. invertebrate larvae. D. green flagellates. E. copepods. Answer: B. Sargassum seaweed. 21. An example of mesoplankton would be: A. larval fishes. B. Sargassum seaweed. C. invertebrate larvae. D. green flagellates. E. bacteria. Answer: A. larval fishes. 22. Those organisms that remain planktonic for their whole lives are called: A. meroplankton. B. holoplankton. C. nanoplankton. D. seston. E. nekton. Answer: B. holoplankton. 23. Those organisms that live only part of their life history as plankton are called: A. meroplankton. B. holoplankton. C. nanoplakton. D. seston. E. pleuston. Answer: A. meroplankton. 24. Nutrient-rich microenvironments can occur in the open ocean around: A. viriplankton. B. discarded larvacean houses. C. marine snow. D. discarded larvacean houses and marine snow. E. viriplankton and discarded larvacean houses. Answer: D. discarded larvacean houses and marine snow. 25. The deep scattering layer refers to: A. an area where organisms are spread apart in a random manner. B. a dense aggregation of migratory zooplankton and fish. C. a safe area where zooplankton can quickly scatter to avoid predators. D. where sonar from whales travels rapidly to facilitate their communication. E. the abyssal zone. Answer: B. a dense aggregation of migratory zooplankton and fish. 26. The primary organisms that make up the deep scattering layer are: A. zooplankton and fishes. B. phytoplankton. C. seston. D. nanoplankton. E. marine snow animals. Answer: A. zooplankton and fishes. 27. Each day the animals of the deep scattering layer: A. must form mucus nets to protect themselves from predators. B. make a nocturnal migration to the DSL to feed. C. make a nocturnal migration to the epipelagic to feed. D. make a daytime migration to the epipelagic to feed. E. migrate to a depth of 1.6 km to feed. Answer: C. make a nocturnal migration to the epipelagic to feed. 28. The primary reason for the daylight migration of many pelagic animals to deeper waters is: A. escape from visual predators. B. escape from the harmful effects of the sun. C. preference for the colder waters of the deep. D. the abundance of food in deeper waters. E. escape from visual predators and the abundance of food in deeper waters Answer: A. escape from visual predators. 29. All of the following are adaptations against predation in the open ocean except: A. transparent bodies. B. colorful bodies. C. colonial lifestyles. D. countershading. E. silvery coloration. Answer: B. colorful bodies. 30. Common megaplankton of the open ocean include all but: A. cnidarians. B. mollusks. C. gelatinous zooplankton. D. diatoms. E. salps. Answer: D. diatoms. 31. Megaplanktonic molluscs without a shell are called: A. cephalopods. B. thecosome pteropods. C. gymnosome pteropods. D. nudibranchs. E. oceanic limpets. Answer: C. gymnosome pteropods. 32. Thecosome pteropods are primarily: A. herbivores. B. carnivores. C. detritovores. D. omnivores. E. scavengers. Answer: A. herbivores. 33. Gymnosome pteropods are primarily: A. herbivores. B. carnivores. C. detritovores. D. omnivores. E. filter feeders. Answer: B. carnivores. 34. All of the following are adaptations against sinking in the open ocean except: A. long spines and projections. B. lipid droplets. C. dense tissues. D. gas bladders. E. small size. Answer: C. dense tissues. 35. To avoid sinking, the purple sea snail: A. uses jet propulsion from the mantle to move upward. B. has wings on its foot for swimming. C. has gas vacuoles in its shell. D. produces a bubble raft surrounded by mucus. E. fills its liver with low-density oil. Answer: D. produces a bubble raft surrounded by mucus. 36. Pelagic snails that produce a bubble raft in order to remain afloat are: A. pteropods. B. purple sea snails. C. cowries. D. littorine snails. E. abalone. Answer: B. purple sea snails. 37. Salps play an important ecological role as consumers of: A. bacteria. B. diatoms. C. krill. D. fish larvae. E. jellyfish. Answer: A. bacteria. 38. Common nekton include: A. tuna. B. billfish. C. jelly fish. D. tuna and billfish. E. billfish and jelly fish. Answer: D. tuna and billfish. 39. All of the following are adaptations of tuna for fast swimming except: A. warmer than ambient body temperature. B. retractable pectoral fins. C. rounded tail. D. operculum that lies tightly against the body. E. sickle-shaped tail. Answer: C. rounded tail. 40. Water comprises at least _______________ of the body of salps. A. 5% B. 10% C. 25% D. 70% E. 95% Answer: E. 95% 41. A fish known for high levels of internal and external parasites is the: A. billfish. B. tuna. C. ocean sunfish. D. shark. E. jellyfish. Answer: C. ocean sunfish. 42. Which non-mammal organism has a connection to supply nutrients to developing embryos similar to the mammals? A. Sea snake. B. Sea turtles. C. Hammerhead shark. D. Manta ray. E. Sea turtle. Answer: C. Hammerhead shark. 43. The manta ray feeds on: A. larger fish. B. surface and diving birds. C. squid. D. small fish and plankton. E. other rays. Answer: D. small fish and plankton. 44. Which organism is considered part of the nekton? A. Frigate bird. B. Penguin. C. Cormorant. D. Snowy plover. E. Albatross. Answer: B. Penguin. 45. Coastal upwelling is a common source of nutrients in the open ocean. Answer: False 46. Pyrosomes are gelatinous zooplankton composed of a colony of individual pelagic tunicates. Answer: True 47. The relationship between salps and the amphipods that eat their insides and live in the hollowed region of the salp body is one of host-parasite. Answer: False 48. Because zooplankton do not need sunlight they tend to be most concentrated in deeper waters away from the surface. Answer: False 49. Physically, the open ocean is a very stable environment. Answer: True 50. The body temperature of tunas is 8-10° C higher than ambient water temperature. Answer: True 51. Many zooplankton migrate daily from the DSL to the epipelagic zone. Answer: True 52. Marine snow is an important source of food for many pelagic organisms. Answer: True 53. Bacteria play an insignificant role in the pelagic realm. Answer: False 54. Squids are dominant nektonic animals. Answer: True 55. Match the organism group with its most closely associated classification group. 1. Classified by taxonomic group bacterioplankton 2. Classified by size kinetic plankton 3. Classified by motility macroplankton 4. Classified by life history meroplankton Answer: 56. Match the organism group with its most closely associated classification group. 1. Life history holoplankton 2. Taxonomic group nekton 3. Size microplankton 4. Spatial distribution viriplankton Answer: 57. Match the phenomena with a closely associated term. 1. Deep scattering layer migratory zooplankton 2. Macropatchines marine snow 3. Micropatchiness aggregations of nekton Answer: 58. Match the characteristic with the most closely associated organism. 1. Purple sea snail bubble raft 2. Gymnosome pteropod winged, small shell 3. Thecoscome pteropod winged, shell absent Answer: 59. Match the characteristic with the species. 1. Ocean Sunfish lack teeth 2. Hammerhead Shark lack swim bladder 3. Billfish cartilage layer 4. Tuna viviparous Answer: 60. Match the size with the most closely associated plankton type. 1. Macroplankton 200 mm 2. Mesoplankton 2.0 mm 3. Microplankton 0.02 mm 4. Megaplankton 20 mm Answer: 61. Match the size with the most closely associated plankton type. 1. Femtoplankton 2.0 mm 2. Nanoplankton 0.2 mm 3. Picoplankton 0.02 mm Answer: 62. Match the location with its most closely associated group. 1. Neuston animals live at or near the surface 2. Holoplankton entire life in water column 3. Meroplankton part of life in water column Answer: 63. Match the species with its most closely associated trophic level. 1. Herbivore diatoms 2. Primary producer copepods 3. 2nd level consumer krill 4. 3rd level consumer squid Answer: 64. Match the species with its most closely associated size/ trophic level. 1. Mesozooplankton foraminiferans 2. Microzooplankton copepods 3. Macrozooplankton krill Answer: 65. What is the deep scattering layer? How was it discovered? What organisms commonly comprise this layer? Answer: The deep scattering layer is a dense layer of migrating animals that moves from the mesopelagic to the epipelagic on a daily basis. It was discovered with sonar and it is composed of zooplankton groups such as crustaceans and siphonophores as well as small lantern fishes. 66. What is meant by the terms "holoplankton" and "meroplankton"? Answer: Holoplankton is a term that refers to permanent plankton in the sea. These are plankton that start out planktonic and remain planktonic throughout their life cycle. Meroplankton are temporary plankton. Included in this category are the larval stages of many benthic and nektonic organisms. 67. What is micropatchiness, and what factors give rise to micropatchiness in the open sea? Answer: Micropatchiness is the phenomenon whereby planktonic organisms along with microorganisms such as bacteria congregate around slowly sinking organic particles of marine snow. The bacteria will first colonize the marine snow. This attracts phytoplankton, which make use of the nutrients released by the decomposing activities of bacteria. Finally, zooplankton are attracted by the enriched marine snow as a food source as well as by the abundant phytoplankton. The ultimate result is that in the open ocean where nutrients are scarce, planktonic organisms are more concentrated around sinking particles that they are in the surrounding water, thus creating patches. 68. What is the ecological importance of salps and larvaceans to the pelagic food web? Answer: Salps and larvaceans filter feed by processing massive quantities of seawater through fine filtration devises. This activity has the effect of concentrating these scarcely abundant phytoplankton within these grazers, which, in turn, are consumed by larger predators. In addition, because the filtration mechanism of salps and larvaceans is so fine, it captures even the smallest nanoplankton, thereby injecting these small producers into the food web. 69. Describe at least 3 of the adaptations used by plankton in their efforts to remain near the surface. Answer: Plankton employ a number of adaptations that either slow down their sinking rate or keep them at the surface. Many of these animals are small in comparison to animals from other habitats. Small bodies mean that the surface area-to-volume ratio will be maximized, thus leading to a relative increase in surface area, which leads to increased friction with the water and slower sinking rates. Zooplankton and phytoplankton also increase their surface areas by having many long spines and projections that increase surface area without substantially increasing volume or density. Some planktonic organisms reduce their density below that of seawater by secreting oil or lipid in their tissues. Other animals reduce their density by substituting water for organic matter in their tissues. A few phytoplankton and many zooplankton are capable of limited vertical movement in the water column. 70. Describe the open-ocean planktonic food chain, and elaborate on why it supports few large animals. Answer: The nutrient-poor open ocean food chain starts with cyanobacteria and nanoplankton. They are consumed by microzooplankton that include foraminiferans and radiolarians which in turn are consumed by copepods. The copepods are preyed on by krill, shrimp, and small fish. These medium-sized animals are fed on by squid, larger fish, and whales. Each step represents a tropic level with a 10 percent efficiency. Larger fish are often five to six steps removed from the nutrient limited phytoplankton. At the fifth level only 0.00001 of the original biomass remains. 71. Define the term "marine snow." What is it composed of? How is it affected by bacteria and other marine zooplankton? How does marine snow aid in the deposition of marine sediments? Answer: Marine snow refers to aggregates of particulate organic matter that sink slowly in the water column. It is composed of the debris of many planktonic organisms; the mucus secretions of fishes, salps, larvaceans, and others; fragmented fecal pellets; and other assorted organic materials. The ecological importance of marine snow is that it forms a habitat for bacteria, phytoplankton, and the animals that eat these two. It is also directly consumed by planktivores and pelagic fishes. Colonizing bacteria tend to enrich these sinking aggregates as a food source for other heterotrophs. Phytoplankton take advantage of the nutrients that are released by the decomposing activity of bacteria. Marine snow is also important because it tends to scavenge small, slow sinking particles from the water column, thereby adding to the mass of the sinking marine snow. Ultimately, marine snow is either consumed by animals in the water column or on the seafloor or it contributes to the deposition of biogenous sediments on the seafloor. 72. Trace the open ocean microbial loop, starting with DOM released by unicells, and follow how it is reprocessed through the bodies of various microorganisms, finally leading up in the bodies of zooplankton. Answer: Single cell organisms are inherently leaky. They and other organisms release dissolved organic matter (DOM) into the water. Heterotrophic bacteria are capable of absorbing this material; acting as recyclers, the bacteria are then consumed by heterotrophic nanoflagellates. The flagellates are consumed by tintinnids and other ciliates. The DOM has now been reprocessed and packaged into organisms that can be consumed by the zooplankton. Chapter 18--Life in the Ocean's Depths 1. All of the following apply to the deep-sea except: A. temperatures vary greatly in deep waters. B. pressures are very high. C. light is dim or nonexistent. D. the water is extremely cold. E. None of these. Answer: A. temperatures vary greatly in deep waters. 2. Hydrostatic pressure within the oceans increases one atmosphere with every _______________ meter increase in depth. A. 1 B. 5 C. 10 D. 100 E. 200 Answer: C. 10 3. The hydrostatic pressure within deep-sea organisms is: A. more than the surrounding pressure. B. equal but opposite force. C. equal and same force. D. less than the surrounding pressure. E. equal with no force. Answer: B. equal but opposite force. 4. The density of cold water at great depths is: A. lower than surface waters. B. similar to the surface waters. C. higher than the surface waters. D. always the same throughout the water column. E. variable, depending on latitude. Answer: C. higher than the surface waters. 5. The density of the organisms living at great depths is about: A. the same as the surrounding density. B. greater than the surrounding density. C. less than the surrounding density. D. the same or greater than the surrounding density E. The same or less than the surrounding density Answer: A. the same as the surrounding density. 6. Deep ocean organisms expend little energy to stay afloat because: A. they have air bladders. B. they have a high oil content. C. of their small size. D. they are the same density as the surrounding environment. E. their metabolism is high. Answer: D. they are the same density as the surrounding environment. 7. All the following are major factors that affect animals living in the deep ocean except: A. light. B. temperature. C. salinity. D. pressure. E. None of these. Answer: C. salinity. 8. The abiotic factor that has had the greatest evolutionary effects on deep-sea animals is: A. low temperatures. B. high pressure. C. low nutrients. D. lack of light. E. varying salinity. Answer: D. lack of light. 9. The main source of light in the deep-sea is: A. the sun. B. bioluminescence. C. underwater volcanoes. D. dinoflagellates. E. anglerfish. Answer: B. bioluminescence. 10. Bioluminescence occurs as a result of: A. luminescent organs. B. symbiotic bacteria. C. conversion of protein luciferin into light energy. D. luminescent organs and symbiotic bacteria. E. symbiotic bacteria and conversion of protein luciferin into light energy. Answer: E. symbiotic bacteria and conversion of protein luciferin into light energy. 11. All of the following are involved in light production of bioluminescent bacteria except: A. luciferin. B. luciferase. C. cellulose. D. oxygen. E. luciferase and cellulose. Answer: C. cellulose. 12. In the twilight zone (150-450 meters) bioluminescence is primarily used for: A. mate selection. B. detecting prey. C. locating prey. D. countershading. E. species recognition. Answer: D. countershading. 13. Bioluminescence of deep-sea animals may be used for all of the following except: A. attraction of prey. B. detection and identification of mates. C. countershading. D. photosynthesis. E. startling a predator. Answer: D. photosynthesis. 14. An organism that has bright lights at the top of its tail fins is called: A. an anglerfish. B. a lanternfish. C. an opossum shrimp. D. a viperfish. E. a gulper eel. Answer: B. a lanternfish. 15. An organism that uses bioluminescence to attract prey is the: A. squid. B. anglerfish. C. stomiatoid fish. D. opposum shrimp. E. anglerfish and stomiatoid fish. Answer: E. anglerfish and stomiatoid fish. 16. Many deep-sea fishes have tubular eyes with: A. a single large retina. B. two retinas. C. multiple retinas. D. no retina. E. compound eyes. Answer: B. two retinas. 17. At the deepest depths many animals find prey by relying on: A. tactile senses. B. chemical stimuli. C. large eyes. D. tactile senses and chemical stimuli. E. chemical stimuli and large eyes. Answer: D. tactile senses and chemical stimuli. 18. Male anglerfish often attach to the female so they can: A. utilize the female’s increased ability to find prey. B. utilize the female’s increased predator avoidance. C. provide sperm to fertilize eggs. D. avoid being eaten by the female. E. obtain growth hormones from her bloodstream. Answer: C. provide sperm to fertilize eggs. 19. Deep-sea fish with large mouths use this adaptation to: A. take chucks of meat off of larger predators probing the deep ocean in search of food. B. threaten other competitors. C. swallow almost anything that comes their way. D. store their large teeth. E. filter-feed on plankton. Answer: C. swallow almost anything that comes their way. 20. All of the following are major components of the deep-sea food web except: A. detritus. B. nocturnal vertical migration to feed near the surface. C. larger predators feeding on the small deep-sea organisms. D. photosynthesis. E. scavenging. Answer: D. photosynthesis. 21. The base of the food web in the deep-sea is: A. phytoplankton. B. algae. C. seagrasses. D. sinking dead matter. E. viruses. Answer: D. sinking dead matter. 22. The major predators of giant squid are: A. gulper eels. B. sperm whales. C. giant octopus. D. vampire squid. E. viper fish. Answer: B. sperm whales. 23. The giant squids of the deep-sea remain a mystery because we lack knowledge of: A. what they feed on. B. their exact size. C. their distribution. D. their anatomy. E. the identity of their predators. Answer: A. what they feed on. 24. A possible reason for deep-sea gigantism is: A. the long life of these animals, compared with shallow-water relatives. B. the healthy diet of these animals. C. the high pressure of these waters. D. the lack of predators, which means longer life and larger size. E. the high metabolism of deep-sea animals. Answer: A. the long life of these animals, compared with shallow-water relatives. 25. Evolutionary biologists find the deep-sea interesting because: A. of the unusual environmental conditions. B. of the abundance of organisms. C. the environment has remained stable for 100 million years. D. the environment is constantly changing due to continental drift. E. All of these. Answer: C. the environment has remained stable for 100 million years. 26. Of the belemnites thought to be extinct, the Challenger Expedition discovered the living fossil genus: A. Spirula. B. Latimeria. C. Neopilina. D. Calyptegena. E. Architeuthis Answer: A. Spirula. 27. The vampire squid was placed in the order Vampyromorpha on account of: A. it has ten arms, but looks like an octopus. B. it appears to drift rather than actively swim. C. it has tentacles that can be coiled up. D. All of these. E. None of these. Answer: D. All of these. 28. An ancient fish that has provided insight into the evolution of tetrapods is the: A. laternfish. B. tripod fish. C. coelacanth. D. redmouth whale fish. E. gulper eel. Answer: C. coelacanth. 29. The limpet-like Neopilina was thought to be extinct for over: A. 100 million years. B. 175 million years. C. 250 million years. D. 350 million years. E. 1 billion years. Answer: D. 350 million years. 30. The limpet-like Neopilina’s ancestors may have led to the following modern groups except: A. gastropods. B. chitons. C. bivalves. D. cephalopods. E. None of these. Answer: B. chitons. 31. The limiting factor for deep-sea benthic organisms is: A. high pressure. B. low temperature. C. available food. D. darkness. E. strong current flow. Answer: C. available food. 32. Deep-sea bivalves differ from their surface relatives by using their siphons to: A. detect the presence of nearby prey items. B. detect the presence of nearby predators. C. vacuum up food. D. detect the presence of nearby prey items and of nearby predators. E. detect the presence of nearby prey items and vacuum up food. Answer: C. vacuum up food. 33. The deep-sea soft-bottom food chain is: ______________. A. infauna – meiofauna – bacteria B. bacteria – meiofauna – infauna C. meiofauna – bacteria – infauna D. meiofauna – infauna – bacteria E. bacteria –infauna – meiofauna Answer: B. bacteria – meiofauna – infauna 34. Diversity refers to: A. the abundance of species. B. the biomass of organisms. C. the abundance and biomass of organisms. D. the number of species. E. the number of individuals of a species. Answer: D. the number of species. 35. Diversity is considered high in the deep-sea due to: A. low dispersal of juveniles leading to speciation. B. stability and old age of benthic environments. C. high infaunal abundance. D. combined low dispersal and long-term stability of the benthic environment. E. high infaunal abundance and combined low dispersal and long-term stability of the benthic environment. Answer: D. combined low dispersal and long-term stability of the benthic environment. 36. White smokers produce a fluid rich in: A. copper sulfide. B. iron sulfide. C. zinc sulfide. D. magnesium sulfide. E. sodium chloride. Answer: C. zinc sulfide. 37. Black smokers produce a fluid rich in: A. copper sulfides. B. iron sulfides. C. zinc sulfides. D. magnesium sulfides. E. sodium chloride. Answer: A. copper sulfides. 38. Chemosynthetic bacteria can oxidize: A. magnesium sulfide. B. copper sulfide. C. hydrogen sulfide. D. oxygen sulfide. E. zinc sulfide. Answer: C. hydrogen sulfide. 39. The base of the food web of deep-sea vent communities are: A. chemosynthetic bacteria. B. cyanobacteria. C. dinoflagellates. D. deep-sea algae. E. benthic diatoms. Answer: A. chemosynthetic bacteria. 40. Primary consumers of the vent communities include all except: A. clams. B. fish. C. mussels. D. worms. E. shrimp. Answer: B. fish. 41. The bivalves and worms have red flesh due to presence of: A. pigments absorbed from their prey items. B. hemoglobin. C. chromatophores. D. pigments similar to other deep-sea organisms due to a lack of light. E. structural colors for camouflage. Answer: B. hemoglobin. 42. Symbiotic chemosynthetic bacteria obtain oxygen from their hosts through: A. hemoglobin. B. myoglobin. C. sulfide-binding proteins. D. luciferin. E. breaking down cellulose. Answer: A. hemoglobin. 43. The deep-sea is characterized by being a very unstable environment. Answer: False 44. The eyes of many deep-sea fishes are tubular. Answer: True 45. Deep-sea vent communities are associated with volcanic ridges on the seafloor and cold-water seeps. Answer: True 46. Larvae of hydrothermal vent animals may aid in the dispersal of these animals. Answer: True 47. Vestimentiferan worms filter feed on nearby suspended chemosynthetic bacteria. Answer: False 48. Vestimentiferan worms lack digestive tissues. Answer: True 49. Vampire squid are actually octopuses. Answer: False 50. The disphotic zone is the deepest part of the world's oceans. Answer: False 51. Photophores of deep-sea fishes may harbor symbiotic bioluminescent bacteria. Answer: True 52. Below the disphotic zone countershading takes on added importance. Answer: False 53. Match the color characteristic with the most closely associated twilight zone fish. 1. Hatchet fish countershading 2. Black stomiatoid fishes iridescent sheen 3. Gulper eels black or brown Answer: 54. Match the use of bioluminescence with its most closely associated species. 1. Laternfish mate selection 2. Opossum shrimp attract prey 3. Anglerfish confuse predator Answer: 1 55. Match the location with the most closely associated project/vessel that made the discovery of deep-sea life. 1. Transatlantic cable below photic zone 2. Galathea Philippine Trench 3. Trieste Challenger Deep Answer: 56. Match the eye characteristic with the most closely associated depth. 1. Twilight zone large - tubular 2. Deep-sea small and less functional 3. Deepest regions tiny, only slightly functional Answer: 57. Match the food capture mechanism with the most closely associated species. 1. Stomiatoids hinged jaws 2. Gulper eels large head/mouth 3. Anglerfish vacuum action Answer: 58. Match the characteristic with the most closely associated diversity component. 1. Diversity number of species 2. Stability number of individuals 3. Abundance how long a community persists Answer: 59. Match the term with the most closely associated manned deep diving device. 1. Trieste manned submersible 2. JASON II bathyscaphe 3. Alvin ROV Answer: 60. Match the tropic level with the most closely associated vent community species. 1. Vestimentiferan worms primary producers 2. Bacteria primary consumers 3. Crabs secondary consumers Answer: 61. Why did the British naturalist Edward Forbes conclude that animal life could not exist in the sea below a depth of 55 meters? Answer: At the time scientists knew only about surface organisms and applied what was known of their natural history and environmental requirements to sustain life to the deep-sea environment. As light gradually is reduced with depth, so is photosynthesis, and thus grazers would be limited. The low light would make finding a mate nearly impossible. Temperatures in the deep remained too cold throughout the year as surface organisms often expand their populations during the warmer periods. Pressure on these animals often was thought to increase beyond their ability to compensate. 62. What physical features characterize the deep-sea? Answer: The deep-sea is characterized by being extremely cold, with an average temperature around 2o C. This environment is also completely dark, with the exception of bioluminescence from marine organisms. Finally, water pressure in the deep-sea is very high. 63. Why do disphotic zone fishes exhibit countershading but fishes that live in deeper waters do not? Answer: In the mesopelagic realm there is still some light from the sun, although very little, that can be used by potential predators to make out the silhouette of prey fish. As a result, fishes in this environment tend to maintain countershading. In contrast, deeper water does not have light at all. This means that there is no need for countershading by these fishes. Fishes in deeper waters tend to be uniform white, gray, or black. 64. Describe at least 3 functions of bioluminescence in deep-sea fishes. Answer: Deep-sea fishes use bioluminescence for a variety of purposes. Some fishes that live in the mesopelagic realm may use bioluminescence as a means of countershading in order to prevent predation or to hide from prey. In dark waters, bright, sudden flashes of light may be used to startle predators and prey. Light may also be used as a means of attracting prey, as in the deep-sea angler fishes that use a light organ as a lure. Light organs may be useful in attracting mates in the dark deep-sea where mates are few and far between. In this regard, producing light in a special pattern on one's body can be useful in species-specific identification as a means of discriminating between potential mates or finding members of one's own species for schooling purposes. 65. How do animals living in the deep-sea tolerate the high pressure and low temperature of these depths? Answer: The animals of the deep have overcome this problem by making it a non-issue. Simply put, they have made their internal body pressures equal to those of the outside environment, thereby preventing collapse. In addition, their body temperatures resemble those of the external water. 66. Why is it necessary for males of some species of anglerfish to parasitize the females? Answer: Because food is so scarce in the deep-sea, and because this area is so vast, it is very rare that an individual will encounter another individual of the same species let alone the opposite sex. Because of this, males will latch onto the first female they encounter in an effort to maximize reproductive output of their species. 67. Describe at least 3 adaptations of deep-sea fishes for improving feeding efficiency. Answer: Many deep-sea fishes tend to be small and inactive. This characteristic alone means that these fishes will not consume large quantities of food because their metabolic rates are fairly low. When they do feed, many deep-sea fishes ensure that they capture and keep their prey by having very large teeth that angle back into their mouths to prevent escape. These fishes will not pass up a potential meal simply because it is too large. Rather, they have expandable jaws and mouths that allow them to take advantage of any food item they happen across. In addition, many deep-sea fishes increase the likelihood of coming across prey by employing attractive measures such as bioluminescent structures. 68. Outline the stability - time dimension of vent communities and how organisms may have adapted to these factors. Answer: The individual vents do not last but 10 to 20 years. In contrast to the surrounding deep-sea, stability is lacking with the vents requiring that the organism have the ability to colonize new vents as they form. The species mature rapidly and produce large amounts of mobile larvae that can be dispersed by deepwater currents. It is possible that they use whale carcasses as an intermediate habitat where they can grow, and in some cases asexually reproduce. 69. Describe why many vent animals that house chemosynthetic bacteria are not harmed by the sulfide compounds in their blood, which normally would be toxic to these animals. Answer: Many of these animals contain sulfide-binding proteins that scavenge any free sulfide. This prevents free sulfides from interacting with other cell biomolecules and causing damage. Test Bank for Introduction to Marine Biology George Karleskint, Richard Turner, James Small 9780495561972, 9780534420727
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