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Details Title: freshwater ecology Description: Test 1 Total Flash Cards: 115 Created: 02/14/2005 16:29:02	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term what is limnology? Definition The study of fresh or saline waters contained with continental boundaries including: lakes, inland seas, ponds, reservoirs, estuaries, wetlands, swamps, bogs, springs, vernal pools, tree holes, streams. Term What is a limnologist? - a. J. R. Vallentyne Definition Freshwater Institute, Winnipeg (1969) wrote in the journal Limnology & Oceanography “ A limnologist is a zoologist who, during summertime, studies chemical and botanical aspects of geologoical problems in readily accessible lakes, 15 m deep, located in the vicinity of universities”. Term editor of L&O, E. S. Deevey and professor at Yale wrote Definition “The head of the world’s leading eutrophication project shows understandable nostalgia for those 15 m days. University lakes of his student days have now shoaled to less than 14-m depth. A modern limnologist is best defined as a biogeochemist and self-taught systems analyst, whose favorite systems are imbedded in an exponentially increasing matrix of septic tanks.” Term F. A. Forel—“Father of Limnology” Definition a) worked on lake Geneva, Switzerland (1868) -- coined the term limnology b) wrote 3 volumes on physics, chemistry & biology of Lake Geneva c) wrote first textbook on limnology in 1901 Term Louis Agassiz 1850 Definition a) published "Lake Superior: Its physical character, vegetation & animals also founded the Museum of comparative zoology at harvard Term S. A. Forbes 1887 Definition published "The Lake As a Microcosm" Term E. A. Birge early-mid 1900’s Definition "Father of American Limnology"--University of Wisconsin Term Paul Welch Definition wrote first American text on limnology in 1935 "Limnology"- -University of Michigan Term Franz Ruttner Definition wrote "Fundamentals of Limnology" in 1940 translated to English 1964 Term G. E. Hutchinson--Yale University- Definition wrote 4 volume "Treatise on Limnology" 1957-1973 Term R. G. Wetzel Definition published first edition of "Limnology" 1975--U of Mich, U of Ala, UNC Term H. B. N. Hynes--University of Waterloo Definition published "The ecology of running waters" 1970. “Father of Stream Ecology” Term J. D. Allan Definition University of Mich--published "Stream Ecology" 1995 Term Water Global distribution Definition 1. ocean 2. polar ice caps / glaciers 3. ground water 4. FW lakes. Term Molecular structure of water Definition a liquid crystal, not a true fluid. - polar hydron bonds. matrix forms and remains a liquid Term properties of water ..Density, temperature relations Definition stratification issues think about arctic diving - due to density , this is important ecology for ice to be on top and not in the water columon. allows animals to escape danger under the ice. The greatest density is 4C m/unit vol. Term properties of water - salinity relations Definition density issue - think about arctic diving. salt decreases freezing point The saltier the water, the more buoyant an object becomes.Very salty water is denser and will sink more; thus very salty water is found at the bottom. Less salty water is less dense and will float on top of the more dense salty water. Term properties of water ...pressure Definition water is 350 times denser than air Density increases with depth Term properties of water - turbidity Definition dissolved particulates, more turbid, more dense. Term properties of water - viscosity Definition thickness, residence to flow Term properties of water - surface tension Definition water strider ecology, hydron bonds orientation. Term properties of water - temperature - specific heat Definition amount of energy required to raise one degree and cal. Term properties of water - temperature - latent heat of fusion Definition ability to melt ice Term properties of water - temperature - latent heat of vaporization Definition takes a lot of heat to vapor. water to stream = 540 cal/g thats a lot to melt / raise Term aquatic life forms - Neuston Definition organisms that live on the surface Term aquatic life forms - nekton Definition swimming creatures. e.g. fish Term aquatic life forms - plankton Definition floater / can move around . maybe a meter in H2O coulum. Term aquatic life forms - plankton - phytoplankton Definition net or macroplankton >200um nannoplankton 20-200um ultra plankton 10-20um picoplankton 0.2-1um Term aquatic life forms - plankton - zooplankton Definition micro crustrations / e.g. rotifers Term aquatic life forms - plankton - seston Definition anything floating in the water partical material in suspetion Term aquatic life forms - plankton - trypiton Definition dead part Term aquatic life forms -benthos Definition animals / plants that live on the bottom Term aquatic life forms - Aufwuchs Definition periphyton- algae that grows on surface of plants epilithon - organims growing on rocks biofilms- on growers Term Bacteria - general Definition omnipresent in the biosphere- can find anywhere prokaryotes - no organized nucleus has cell wall of peptido-glycans most <5 micrometers pop. increase rapidly by asexual reproductions. Term bacteria- imporatance in ecosystem energetics and process -autotrophs Definition can convert inorganic to organic material Term bacteria- imporatance in ecosystem energetics and process - photoautotrophs Definition use light Co2+H20 - carbohydrate using sun. Term bacteria- imporatance in ecosystem energetics and process -chemoautotrophs Definition use chem, use inorganic chem reaction, use for carbohydrate sythesis e.g. rust in stream bed. ocean = communities depend on chemoautotrophs Term bacteria- imporatance in ecosystem energetics and process -hetroautotrophs Definition get energy from somewhere else - soaking up enery from environment. Term bacteria- imporatance in ecosystem energetics and process -nutrient cycling Definition ammonia to nitriate Term bacteria- imporatance in ecosystem energetics and process - decomposition (mineralization) Definition organic to inorganic Term bacteria- imporatance in ecosystem energetics and process - waterborne disease organisms Definition typhoid cholera legionelaa gastroenteritis these go through the population easy Term cyanobacteria - bluegreen bacteria -NOT ALGAE ) - general characterisitcs Definition found in hot springs where there is lots of phosophous. prokaryotes - no organized n neucleous cell walls like bacteria _ e.g. - peptido-glycans polysaccharide stored as glycogen unicellular, filamentous, colonial very tolerant of harsh environmental conditions populations increase rapidly by asexual reproduction. Term bacteria- imporatance in ecosystem energetics and process Definition -blooms and nitrogen Term bacteria- imporatance in ecosystem energetics and process -consequences of blooms Definition ecological human concerns - anabaena flos-aquae microcystis sp. both - toxic to humans aphanozomemnon flos-aquae toxic to fish/humans Term chlorophyta -green alage general characteristics Definition eukaryotes - can see nucleus- membrane bound cell walls cell walls of cellulose polysaccharides stored as starch - unicellular, filamentous, or colonial populations may increase rapidly by sexual reproduction well developed sexual reproduction-variety important primary producers in most aquatic systems (photosynthetic) cannot compete with cyanobacteria in low N conditions good food for consumers Term Dinophyta -dinoflagellates Definition produce red tide, produce oil to float. very huigh quality food for grazers due to oils may be limited by P and N like other algae but also Si02 (glass) unicellular flagellates with cellulose shell (theca) many produce red tides = toxic blooms in marine systems pfisteria blooms in estuaries due to N pollution threat to human health Term Diatoms Definition mostly unicellular but some are colonial protoplasm encased in SI02 (glass) shell frustule or theca Term Diatoms - epitheca Definition upper half Term Diatoms - hypotheca Definition lower half Term Diatoms - girdle Definition protein band holding two halves together Term Fungi Definition eukaryotes - like higher plants , but cell walls made of CHITIN - has N in it cell walls mostly chitin Term funig - saprotrophs Definition absorb Disvoled organic compounds from environment or parasities Term fungi - obligate symbionts Definition as in lichens or mycrorhizzaw - symbolisis Term fungi body forms - mycelium Definition for feeding and growth Term fungi body forms - fruiting body Definition for reproduction Term fungi - aquatic hyphomycetes Definition member of fungi imperfecti - no sexual reproduction first organisms to begin decay processes spread about via asexual spores. Term Macrophytes Definition higher plants "large plants" growing in lakes / streams whereever there is H20 they grow "can choke off surface water " Water willow" - helps form islands / land grows like strawberries - traps sediments. strong root system - common in southern rivers. many produce toxic chemicals, not much feeds on macrophytes are important sources of food for things that like dead organic matter. they take up a lot of nutrients can regulate nutrients good for stopping sedimentation. Term A. Rotifers General Features Definition a. 0.1-1.0 mm long b. body cylindrical, sac-like or worm-like c. body generally covered by a shell (lorica) d. most have crown of cilia (corona) used to swim and/or gather food e. mastax--chitinous “jaws” a) variously specialized for feeding b) important feature used to identify Term Rotifers - ecology Definition a. locomotion--most swim at some stage in the life cycle using corona b. feeding--many filter feed on seston but some are predators c. habits--may be planktonic or benthic, single or colonial d. anhydrobiosis--undergo dehydration and form resistant cyst e. periodicity--large, seasonal fluctuations in population density f. vertical migration--daily vertical movement thru the water column g. trophic relations--primary consumers and predators--important in food webs of most lakes Term Rotifers - life history Definition a. mictic cycle b. amictic cycle Term cladocera "water fleas" -general features Definition a. 0.3-2mm long b. definite head; body (thorax & abdomen) enclosed in bivalved carapace(shell) of chitin ending in a sharp spine c. pair of conspicuous compound eyes d. two pair of antennae: 1st small; 2nd conspicuous e. many leg like appendages used in locomotion & feeding Term Cadocera (crustaceans ) "water fleas" - ecology Definition a. locomotion--”jump” thru water using antennae like oars b. feeding--planktonic forms filter feed on seston and select particles based on size. benthic forms may feed on detritus or be predators c. habits--most species are freshwater, planktonic d. periodicity--large seasonal fluctuations in density e. vertical migration--daily vertical movement in water column f. cyclomorphosis--changes in shape in succeeding generations g. trophic relations--primary consumers extremely important in food webs in many lakes, especially for larval fishes Term cladocera "water fleas" -life cycle Definition a. most individuals are parthenogenic females thru most of the year producing many young carried in brood chamber until development is over b. sexual females occur late in growing season, brood 1 or 2 young, that may 3 become encased in a “resting chamber” or “ephippium” for over wintering. c. In some species, females over winter Term Copepoda (crustaceans) copepods - gen. features Definition a. 0.5 -2.0 mm long--some up to 5 mm b. body generally tear-drop shaped to cylindrical c. body segmented with many pairs of appendages--no carapace d. 1st antennae conspicuous, 2nd antennae less so e. single median (nauplier) eye--no compound eyes Term cladocera "water fleas" -ecology Definition a. locomotion--also “jump” thru water using antennae like oars b. feeding--planktonic forms filter feed; benthic forms feed on detritus or are predaceous; some are parasites c. habits--most species are marine, about 10- 15% are freshwater. There are many planktonic and benthic species and can be found in virtually all aquatic habitats and in moist soils. d. Important in lake & stream food webs e. periodicity--large seasonal fluctuations f. vertical migration—daily g. trophic relations--primary consumers-- fed on by variety of invertebrate & vertebrates in lakes & streams Term cladocera "water fleas" -life cycle Definition a. most species are sexual 4 b. release immature larvae that go through numerous stages before becoming adults-- a marine-type life cycle c. many diapause (form a resting stage) to over winter or to avoid drying Term Gastropods -snails- General features Definition a. most inhabit coiled shells made mostly from calcium carbonate and protein--some (limpets) have cap-like shells b. size range from a few mm to several inches c. characterized by presence of radula (for feeding) and foot (for locomotion) d. Prosobranchs have gills; Pulmonates have lungs Term Gastropods -snails- ecology Definition a. feeding--most are scrapers--scrape surfaces for food using radula b. habits--most are benthic or epiphytic; distributed widely in aquatic systems where there is sufficient calcium-- generally absent in water with acid pH. c. trophic relations primary consumers-- provide food source for a wide variety of aquatic predators and are very important in food webs of most aquatic systems Term Gastropods -snails- life cycle Definition a. Most are sexual--some hermaphroditic but cross fertilize. b. Females produce lots of eggs c. Most remain active over winter Term bivalves- mussels and clams -general features Definition a. all freshwater forms inhabit a bivalved shell composed of calcium carbonate & protein b. size range several mm up to 12 inches or more c. characterized by presence of large foot used in locomotion d. also characterized by presence of large gill used for: a) filter feeding b) gas exchange c) brooding eggs and/or juveniles d) gill chamber irrigated by water currents entering thru incurrent siphon Term bivalves- mussels and clams - ecology Definition a. feeding--all freshwater forms are filterfeeders b. locomotion--most move about very little but can “crawl” on the surface or burrow into the substrate using the muscular foot. Juveniles may move with water currents c. habits--adults are benthic and generally remain buried to one degree or another in the substrate of lakes and some streams d. native species very susceptible to siltation and toxics e. trophic relations-- primary consumers--fed on by a variety of vertebrate predators in streams & lakes Term bivalves- mussels and clams -life cycle - -spaeriidae- fingernail clams Definition Sphaeriidae--fingernail clams 6 a) most widely distributed of freshwater bivalves b) females brood embryos to juvenile stage and release Term bivalves- mussels and clams -life cycle - -Corbicula -asian clam Definition a) exotic introduced at turn of century from Asia b) brood embryos to juvenile--very high birth rates c) serious biofouler Term bivalves- mussels and clams -life cycle - -Dreissen - zebra musssel Definition a) Facultative marine exotic introduced USA 1985—marine-type life cycle b) females release mobile veliger larvae c) highly invasive, stick to surfaces and each other using byssal threads d) super-serious bio-fouler Term bivalves- mussels and clams -life cycle - -unionidae Definition a) many NA species rare and endangered or threatened with extinction b) brood embryos to glochidia which are expelled and parasitic on particular species of fish. c) Failing to find the proper host fish, glochidia die within a short time. d) glochidia on right hosts develop into juveniles, drop off fish and take up residence in sediments Term oligochaetes- aquatic "earthworms" general features Definition a. segmented worms bearing setae (chitinous bristles) b. size range from a few mm to several inches in length 7 c. most exchange gases across body wall thus body wall is well supplied with capillaries d. blood contains hemoglobin to transport oxygen between exchange surface(skin) and tissues Term oligochaetes- aquatic "earthworms" - ecology Definition a. feeding--most feed on organic material in the substrate b. locomotion-- move by crawling on surface or burrowing c. habits--most are benthic and burrow in the substrate of lakes & streams d. many are tolerant of low oxygen conditions and toxic chemicals and have been used as “indicators” of organic pollution e. trophic relations--primary consumers-- may be very important in some food webs Term Branchiobdellida - branchiobdellids - general features Definition a. unevenly segmented worms that live as commensals on crayfish b. size range 0.8 to 10 mm length c. mouth fitted with chitinous jaws suited for scraping surfaces d. posterior end fitted with sucker for hanging on to surfaces Term Branchiobdellida - branchiobdellids - ECOLOGY Definition a. habits--live in various creases and crevices on crayfish and other crustaceans b. feeding--apparently feed on biofilms growing on crayfish c. trophic relations--not particularly important in most systems 8 Term Hirudinea—Leeches 1. General features Definition a. segmented worms (related to oligochaetes) that are dorso-ventrally flattened b. mouth with chitinous jaws for predation and sucking blood c. posterior sucker for holding on to prey d. size 5mm to 18 inches Term Hirudinea—Leeches Ecology Definition Ecology a. feeding-many are predators on a variety of aquatic animals, many suck blood from vertebrates, some are scavengers b. trophic relations--may be significant predators in some systems-- also eaten by vertebrates Term Amphipoda—amphipods, scuds, or sideswimmers 1. General features Definition a. laterally flattened crustaceans b. large crushing “jaws” called mandibles used for chewing c. body divided into 3 regions (head, thorax & abdomen) and with chitinous exoskeleton that contains high concentration of Ca d. all body regions segmented with paired appendages on each segment-most about 1 cm Term Amphipoda—amphipods, scuds, or sideswimmers Ecology Definition a. feeding-- most are detritivores but some may feed on living vegetation--young feed on biofilms b. habits--benthic--widely distributed on and in substrate and aquatic plants in freshwater systems including caves & 9 springs—cave species frequently endemic an are thus rare & endangered. Many marine species c. locomotion--”side-swimming” using appendages d. trophic relations--as primary consumers, very important in food webs, especially in springs & caves Term Amphipoda—amphipods, scuds, or sideswimmers life History Definition life History a. sexual reproduction only--most breed continuously so you always find a range of ages(sizes) in specific populations b. like other arthropods, the exoskeleton is shed (molted) periodically and replaced-- this is the only time the animals can grow larger--most species go thru about 10 “molts” between birth and adulthood Term Isopoda—isopods or sow-bugs 1. General features Definition a. dorso-ventrally flattened crustaceans b. also with mandibles c. body in 3 regions, segmentation, appendages, & exoskeleton as in amphipods—most are <1 cm long Term Isopoda—isopods or sow-bugs Ecology Definition a. feeding-most are detritivores and/or scavengers--young feed on biofilms b. habits--same as amphipods. in fact, amphipods & isopods are almost always found together in springs & caves. Many are endemic to specific springs or caves c. locomotion--mostly crawl on and in substrate & vegetation d. trophic relations--same as amphipods 10 3. Life history a. very similar to amphipods Term Crayfish 1. General features Definition a. relative large crustaceans ranging from 5 up to 35 cm b. body divided into 2 distinct regions: cephalothorax (fused head & thorax) and abdomen c. 2 pairs of long antennae and 1 pair of conspicuous compound eyes on head region d. thorax with 5 pr walking legs, first pair enlarged chelipeds pincers) and covered by dorsal shield (carapace) e. abdomen with paired appendages on each segment f. exoskeleton of chitin with high concentrations of Ca Term CRAYFISH 2. Ecology Definition 2. Ecology a. habitats--wide spread in freshwater including caves and groundwater where Ca is sufficient. b. Many live under large rocks, wood, etc.-- others burrow in mud c. feeding-- some graze algae, some shred leaves, some filter feed, most are predators at times--call them omnivores d. locomotion--mostly crawl but can “jet” backward using the tail e. trophic structure--omnivores that are favorite food of many aquatic & terrestrial vertebrates Term CRAYFISH Life History Definition a. generally breed once a year--female broods eggs under abdomen and carries young around for a time after hatching. b. can only grow after molting . Term A. General features of insects Definition 1. body is divided into 3 distinct regions a. head a) 1 pair of antennae b) 1 pair large compound eyes c) 1 to several ocelli (simple eyes) d) complex mouth parts 1) labrum-fused “upper lip” 2) mandibles-paired 3) maxillae-paired 4) labium-“lower lip” b. thorax a) three pairs of walking legs in larvae and adults b) two pairs of wings in adults except for Diptera (1 pair) and some wingless forms. Wings absent in immatures c. abdomen a) lack true appendages but may have external structures associated with reproductive system Term insects- life cycles Definition B. Life Cycle Types 1. General features a. most species have relatively long lived aquatic immatures. b. Most species have relatively short lived terrestrial adults with notable exceptions. 2. Holometabolous (complete) metamorphosis a. life cycle has 4 stages a) egg b) larva—up to 6 larval stages separated by molts c) pupa d) adult (imago) b. in some, all stages are aquatic c. in most, egg, larvae, and pupae are aquatic-adults are terrestrial d. in some, egg & larvae are aquatic, pupae and adults are terrestrial e. in some others, eggs, larvae & adults are aquatic, pupae are terrestrial. 3. Hemimetabolous (incomplete or gradual) metamorphosis a. life cycle has 3 stages a) egg b) larvae or nymph—may have up to 30 larval stages separated by molts c) adult b. eggs and larvae are aquatic, adults are terrestrial Term C. Ephemeroptera—mayflies 1. General features Definition a. nymphal body flattened or cylindrical b. generally with 3 cerci(tails) but some have 2 c. plate-like abdominal gills d. large compound eyes and noticeable antennae e. most have ocelli as nymphs Term Ephemeroptera—mayflies ecology Definition a. most are primary consumers--eat detritus or algae; a few are predaceous b. wide spread in lakes, streams, and other freshwater habitats c. nymphs are generally considered to be sensitive to pollution d. serve as food for a variety of invertebrates & vertebrates Term Ephemeroptera—mayflies - life-history Definition a. hemimetabolous b. nymphal life normally 5-8 mo with 12-30 instars; adults very short-lived(hours to days) c. last nymphal instar molts into sub-imago (winged but sexually immature)—wings are smoky rather than clear as in mature adults d. Subs go thru an additional molt to become sexually mature adults only insect that molts after becoming winged. e. mating occurs in swarms, female dies shortly after laying eggs Term D. Odonata--dragonflies & damselflies 1. General features Definition a. nymphal body of dragonflies broad & flat or thick and cylindrical b. damselfly nymphs generally cylindrical and thinner c. both with extendible, raptorial labia (lower lip) for prey capture d. dragonfly nymphs have internal rectal gills; damselfly nymphs have external terminal gills e. damselfly adult fold wings over back at rest; dragonfly adult wings remain spread laterally f. large eyes, small antennae Term Odonata--dragonflies & damselflies - ecology Definition a. wide spread in lakes, stream, marshes b. nymphs & adults predators c. adults display complex behaviors d. nymphs & adults fed on by wide variety of predators Term Odonata--dragonflies & damselflies -life history Definition 3. Life History a. hemimetabolous b. nymphs live 1-3 years; adults live up to 3 months c. last instar nymph crawls out of water to molt to adult Term E. Plecoptera—stoneflies 1. General features Definition a. nymphal body cylindrical or dorso-ventrally flattened b. nymphs always with 2 tails, no abdominal gills--may have coxal, cervical, or anal gills c. large eyes, conspicuous ocelli, prominent antennae Term Plecoptera—stoneflies- Ecology Definition 2. Ecology a. generally restricted to clean, cool, fast moving streams, sensitive to pollution b. nymphs predators or detritivores; most adults don’t feed c. adults poor flyers, secretive d. nymphs & adults important in food webs Term Plecoptera—stoneflies - life history Definition 3. Life History a. hemimetabolous b. nymphal life 8 months to 4 years, adults short lived c. last nymphal instar crawls out of water to molt into adult emerge at all times of year including winter, adults display courtship behaviors including “drumming” on substrate to attract females Term F. Hemiptera—bugs 1. General features Definition a. nymphs & adults have “piercing-sucking” mouth parts(stylet)-- penetrate prey, release digestive enzymes, suck out dissolved insides b. some highly adapted for swimming in water or “skating” on surface c. many have long breathing tubes Term Hemiptera—bugs- Ecology Definition a. nymphs and adults are predators b. many species have fused wings, never leave the water. Some do fly and are attracted to lights c. more species in lakes but there are some “stream” species, some occupy hot springs or saline ponds d. many have scent glands with which they ward off predators Term Hemiptera—bugs - life history Definition a. hemimetabolous b. most have annual cycles Term G. Megaloptera—Dobsonflies, alderflies - General features Definition a. larvae (called hellgrammites) with large, sclerotized head with prominent mandibles. b. abdomen soft, very long, each segment with paired lateral filaments (with some exceptions), and pair of terminal hooks. c. some with prominent abdominal gills at base of lateral filaments; others with dorsal breathing tubes near tip of abdomen Term Megaloptera—Dobsonflies, alderflies - Ecology Definition 2. Ecology a. widely distributed in streams, lakes, springs, seeps b. voracious predators c. favorite food of many fish, each other, and other invertebrates and vertebrates Term Megaloptera—Dobsonflies, alderflies -Life History Definition a. holometabolous b. larval life 2-4 years, adult life a few weeks c. last instar larvae leave water, build a pupal cell in mud or old log and pupate. d. Adults totally aerial--lay eggs in cases over water- hatchlings drop into water and begin life e. Adults are very large and conspicuous Term H. Trichoptera--caddis flies 1. General Features Definition a. larvae worm-like but with insect legs and many have highly sclerotized heads, dorsal shields on thorax, terminal sclerotized prolegs b. many have abdominal gills c. adults resemble moths (have scales on wings) but fold wings tent- like over the back and have very long antennae Term Trichoptera--caddis flies- Ecology Definition a. widespread in most freshwater habitats, some semi-terrestrial, some are commensals with estuarine crustaceans b. extremely diverse group with respect to functional feeding group: herbivores, detritivores, predators c. frequently most numerous and most productive invertebrates in streams thus extremely important in stream food webs d. many construct protective cases of materials ranging from silt to pebbles. many are silk-net spinners--show close affinity to Lepidoptera(moths & butterflies) Term Trichoptera--caddis flies-life history Definition a. holometabolous b. larval life 8-10 months, pupae & adults relatively short-lived c. adults appear to produce pheromones for sex attractants again showing relationship to Lepidoptera d. last larval instar constructs silken pupal case, molts into pre-pupa, which then molts into pupa in the water. e. Emerging adult leaves pupal case in water and must swim to and break thru the surface film. f. females lay eggs under water, then die Term I. Coleoptera--beetles 1. General Features Definition a. larvae take many forms--some resemble megalopterans, others resemble caddisflies. b. larvae characterized by heavily sclerotized head with sickle-shaped mandibles c. adult forewing modified as elytra (hard shell) that covers hind wing Term Coleoptera--beetles--Ecology Definition a. widespread in all aquatic habitats including caves, hot springs brine pools b. larvae include: predators, scrapers, detritivores; adults same c. adults of most species remain in the water almost full time but can fly and are often attracted to lights d. many adults have defensive glands that protect them from predation, but beetles are still important in food webs e. beetles are the most diverse of the insect orders on land and in the water--it is difficult to make generalizations that apply to all groups Term Coleoptera--beetles - life history Definition 3. Life History a. holometabolous b. most larvae require 6-10 months to mature. last instars leave water and construct a pupal cell on land. c. most adults probably do not live very long in nature but can be kept alive in for years in the lab Term J. Diptera--true flies 1. General features Definition a. larvae are legless and worm like--called maggots b. adults take many forms but the presence of 1 pr wings sets them apart from all other insects Term Diptera--true flies--Ecology Definition a. dipteran larvae are found virtually everywhere in freshwater; many are estuarine and many are adapted to living in hypersaline waters like the Great Salt Lake and the Dead Sea b. adults are aerial creatures, many display complex mating behaviors c. dipteran larvae run the full range of functional feeding groups in aquatic habitats including cannibalism and parasitism d. adults range from DOC feeders to sucking vertebrate blood e. larvae of certain groups e.g., Chironomidae, are often numerous under polluted conditions and are considered tolerant in general. f. dipteran larva & adults are almost always very important in the tropic dynamics of habitats they occupy Term Diptera--true flies--Life History Definition a. holometabolous b. most go thru 4 or 5 larval instars, construct a pupal case, and pupate in the water or damp habitats. c. some may pass from egg to egg in about 3 weeks and can have 5-10 generations per year; other have a single generation that lasts 6 months