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229 Cards in this Set
- Front
- Back
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common name for platyhelminthes? |
flatworm
or acelomates which means "body without a cavity" |
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Space between epidermis and gastrodermis is filled with a CELLULAR material of mesodermal origin...
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parenchyma
(means sorta infusion) |
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Charachteristic of flatworm embryo?
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triploblastic (ectodrem, mesoderm and endoderm)
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What lies within the parenchyma?
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mesodermal organs.
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In flatworms does the mesoderm give rise to?
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- mesoderm gives rise to TRUE tissues (muscles, organs, bones, heart and circulatory, reproductive, kidneys and urinary,
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what do we can the flattening of the acoelmates?
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Dorso-ventrally flattened
(means back and front) |
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In flatworms does the ectoderm give rise to?
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skins and associated tissue...some dermal glands
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In flatworms does the endoderm give rise to?
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gut lining and associated structures, some digestive glands
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4 sufaces of bilaterally symmetrical animal?
And what is associated with bilateral symmetry? |
dorsal- back
ventral- front anterior- head posterior- bottom Cephalization is associated with bilateral symmetry, |
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how does excretion and respiration occur?
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simple diffusion
(easier because of flattened body) |
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What level of organization do we find in platyhelmenthes?
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Organ system level.
(digestive and nervous systems arise from mesoderm) |
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What kind of digestion do we find in platyhelmenthes?
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INCOMPLETE
mouth, but no anus, so 1 at a time! |
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What kind of platyhelmenthes absorbs nutrients through specialized "Skin"?
What is this "skin" called? |
flukes and tapeworms
Tegument (with hairy look for increased surface area) |
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Microtrix?
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look like cilia which increase surface area of tegument on flukes and tapeworms.
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How many pairs of nerve cords can be found in platyhelmenthes?
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up to 5 pairs
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Nervous system in freshwater flatworms?
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one pair of lateral nerve cords connected to cerebral ganglia.
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cerebral ganglia
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In flatworms, the bundle of nerve cells in the head. Connected to lateral nerve cords.
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Osmoregulation in platyhelmenthes?
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FLAME CELLS lined with cilia drive fluids through a series of tubules which open to outside through a series of pores. (the cells resemble a flame)
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Classes of platyhelmenthes (4)?
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-Turbellaria (free living flatworms)
-Monogenea (small ectoparasites on fish) -Trematoda (larger flukes, endoparasites) - Cestoda (tapeworms) |
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Turbellaria are_______ and
2 examples include... |
Free living flatworms.
1.Dugesia- the live specimen we observed 2. colorful marine flatworms (Turbellarians are platyhelmithes/flatworms) |
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Turbellarian digestive system?
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Y- shaped with eversible (turns out of body) pharynx
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eversible pharynx
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Turbillarian "mouth"...tube which can be extended out from the body for feeding, though normally held within the body.
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Turbellarian Reproduction?
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All are monoecious (hermaphroditic).
Produce asexually by fission. Produce sexually by complex organ system syngamy (egg & sperm). |
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Monogenea
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(slide looks like a pink "tremor")-
-external fish parasite -does not harm host -of the phylum nematode (flatworm) |
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haptor
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aka opishaptor
-attachment appendage for monogenea (attaches to fish gills) |
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Monogenean reproduction?
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hermaphroditic but only reproduce SEXUALLY.
Only one adult is produced per egg, but can produce 20K eggs. (monogeneans are the fish ectoparasites) |
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Trematode
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-a nematode
-Flukes (many are liver, there is also a blood fluke) -endoparasites with 2 or 3 hosts -SNAIL is always an intermediate host, but the definitive host is always a vertebrate. |
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Characteristics of parasites...
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- Loss of sensory structures, such as eye spots and tactile sensors
-Loss of some organ systems, such as digestive (absorb instead) -Increased reproductive potential to ensure survival of species |
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definitive/primary host
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Where parasite has sexual reproduction
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secondary/intermediate host
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Where parasite has asexual reproduction.
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metagenesis
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reproduction characterized by the alternation of a sexual generation and a generation that reproduces asexually; alternation of generations.
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Trematode reproduction
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both sexual and asexual reproduction aka metagenesis (alternation of generations).
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Human liver fluke (clonorchis) life cycle :
(flukes/trematodes of platyhelminthes) |
- human eats metacercia encysted in fish muscle.
-cyst develops into adult which reproduces sexually in liver -egg containing miracidium larva is excreted. -snail eats miracidium larva ( or burrows) --miracidium develops into sporocyst where redia develop (redia feed on snail tissues) -cercaria (looks like sperm) develop asexually inside the redia. -cercaria are released into water and swim up and down until they find a fish (2nd intermediate host) -cercaria develops into metacercaria which encysts in the fish muscle. (which then may be eaten by a human, etc) |
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What disease is caused by Clonorchis sinensis (human liver fluke)?
How can it be avoided |
Clonorchiasis.
Worms can live 30 years and cause cirrhosis of the liver (excessive scarring). Sanitary disposal of human feces. Thoroughly cook fish. |
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Which of the top 3 infectious diseases of our time (WHO) is caused by a nematode?
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Shistosomiasis. (fluke)
300 Million affected world wide. |
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What organism causes Shistosomiasis?
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Human blood fluke; shistosoma sp.
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Shistosoma (human blood fluke) reproduction?
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Dioecious- female lives in male's external ventral canal.
Syngamy! |
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Mechanism (cycle) behind schistosomiasis?
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-cercariae burrow directly into skin of humans (NO CYST STAGE)
-cercariae enter human blood/circulatory system and grow to adult. -eggs laid by female (who lives in external canal of male) pass from the circulatory system into the digestive system and pass out of the body in feces. - eggs to snail and then sporocyst, then cercariae directly to human skin. |
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swimmer's itch
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-dermatitis caused by cercaria of a trematode fluke
-temporary because humans are wrong definitive host. |
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What class are tapeworms in?
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cestoda
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Cestoda
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*tapeworms
-endoparasites of the vertebrate digestive system with specialized anatomy |
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scolex
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tapeworm "head" with hooks for attachment and suckers neat attachment site.
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proglottid anatomy
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-have male and female reproductive organs (testes, ovaries, uterus, vagina, sperm duct, and vitelline gland (yolk production))
-nerve cords -flame cells (for osmoregulation) -excretory ducts -muscles -parenchyma |
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Tapeworm reproduction
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-monoecious (hermaphroditic)
-no asexual reproduction or self fertilization. Proglottids |
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Life cycle of beef tapeworm
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-Proglottid crawls out of feces onto vegetation
-proglottid dries and ruptures scattering embryos (which can live to 5 months) -cattle eat grass and ingest the eggs -oncosphre hatches from egg and uses hooklets to burrow through the digestive system to circ system. -encysts in cow muscle (cysticercus) -human eats meat, and scolex turns right side out to attach to intestinal lining and develop into a (proglottid producing) adult. |
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cysticercus
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encysted tapeworm embryo with an inside out (invaginated) scolex
*encysts in muscle |
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oncosphere
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tapeworm embryo
(hatches from egg inside cow and travels to cow muscle) |
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How many Americans are affected by tapeworms? (%)
How can it be avoided? |
1%
Thoroughly cook meats. |
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tapeworms are found in
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dogs, cats, humans, fish poultry.... vertebrates
encyst in liver, kidney, heart, brain |
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Problems caused by tapewoms?
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MANY!!
liver enlargement, tenderness jaundice nausea, vomiting, diarrhea muscle weakness irritability increased heart rate ETC!! |
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Roundworms are what phylum?
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Nemotodes!!!
aka pseudocoelomates |
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Common name for nematodes?
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roundworms
or pseudocoeloamtes |
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Where are nematodes found?
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(roundworms)
50% ocean 25% soil and freshwater 15% in animals 10% on or in plants |
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How are nematodes important to ecosystems?
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important detritivores
*1 cubic meter of soil can have a BILLION nematodes!! |
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nematodes....parasites or not?
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Most are NOT (85%)....but many are (15%).
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What phylum are psuedocoelomates?
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roundworms/ Nematodes
means "false body cavity" |
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Differentiate by Phyla....
Acoelomate Pseudocoelomate Eucoelomates |
A- platyhelminthes
Pseudo- nematodes Eu- annelids |
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pseudocoelom
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in nematodes-
body cavity where mesodermal organs and gut reside |
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origin of pseudocoelom
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blastopore pushes its way through blastocoel. Pseudocoelom arises from blastocoel.
Blastopore becomes the nematode's COMPLETE digestive track. *sometimes described as a tube within a tube |
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complete Digestive track
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mouth and anus separate- 1 WAY.
Nematodes and annelids have this, platyhelminthes do not! |
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Nematode reproduction
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almost all are dioecious
simple repro system Asexual reproduction DOES NOT occur in nematodes/roundworms |
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Body plan of nematodes
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dioecious
-little if any cephalization superficially simpler than platyhelminthes -generally no cilia or flame cells -only longitudinal muscles, no circular. *they must be in moist surrounding or they will desiccate |
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advantages of pseudocoelom (over acoelomates)
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-complete digestive track- can eat and poop at the same time.
-longitudinal muscles are more effective because fluid in coelom acts as hydrostatic skeleton. -space for organs to develop complexity -though there is no circulatory system, materials circulate through coelom fluid |
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protonephridia
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In NEMATODES.
flame cells connected to nephridial tubes- for osmoregulation. *Name implies primitive form of kidneys |
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Osmoregulatory/excretory system in Nematodes?
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-Excrete ammonia which diffuses across the body wall
-osmoregulation is poorly understood- could be linked to excretory duct and gland cells *no flame cells or protonephridia |
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circulatory and respiratory system in nematodes?
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none...
nematodes use diffusion (implies small body size) |
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Nervous system of nematodes?
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-dorsal and ventral nerve cords
-also nerve ring around pharynx that connects dorsal and ventral -Chemo and tactile sensory. (compare: flatworms have lateral nerve cords) |
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pseudocoelomates other than nematodes?
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phylum rotifera (with ciliated corona and teil-like foot with 2 toes)
phylum Neatomorpha |
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What problem does a complex life cycle pose to parasitic nematodes and how do they deal with this?
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- their life cycles are easy to break- a lot of things could go wrong.
-they produce a tremendous amount of eggs per adult using SEXUAL repro. |
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scientific name of the human nematode?
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Ascaris Lumbricoides
*We study ascaris suum (pig nematode) because of its size & availability. |
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how many eggs can be laid per day by female ascaris (parasitic nematode)?
What happens to these eggs? |
200 K per day!
They pass out of the host in feces. Juvenilles develop in shells and can remain viable for up to 20 years in the right conditions. |
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Ascaris life cycle
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(parasitic nematode)
- eggs ingested (unwashed veggies or unsanitary cond.) -eggs hatch and larva burrow through intestinal wall to veins or lymph vessels and are carried to lungs -larva enters lungs causing infection and pneumonia -larva are coughed up and swallowed -then they mature and adluts live in intestines and feed on contents of small intestines. |
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syptoms of Ascaris (parasitic roundworm/nematode)
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adlut worms cause abdoinal symptoms, allergic reaction, blockage and perforation of intestines resulting in peritonitis. (wandering worms may enter ear :/ )
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what nematode is common in cats and dogs?
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toxocara
(life cycle similar to ascaris) |
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toxocara
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nematode is common in cats and dogs
(life cycle similar to ascaris) -juveniles remain in state of arrested development unless female become preg, then they infect embryos in uterus. Puppies are then born with worms :( -humans are not the host, but they can caus damage by wandering around our bodies. *Dispose of doggy waste properly. |
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which nematode is on WHO's list of top 3 infectious diseases? (world health org)
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Hookworm:
Necator Americanus |
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Symptoms of Necator (parasitic hookworm)?
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-retarded physical growth in children and loss of energy
-anemia occurs as adults feed on blood after they attach to intestinal lining |
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How is the life cycle of Necator (hookworm) similar to ascaris (human &pig nematode) and toxocara (dog and cat nematode)?
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hookworm larva pass from bloodstream to lungs, and then to digestive system
-differs because eggs hatch in soil, and juvenile worms penetrate bare feet. Avoid this parasite by wearing shoes. |
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Trichinella Spiralis:
lifecycle and disease... |
causes trichinosis...there is no treatment, but his disease can be avoided by cooking meat.
Trichinella is an intestinal parasite as an adult, but bloodstream carries larva to muscle (instead of gut) where they incyst *painfully* looks like a "Spiral" |
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what parasite causes trichinosis?
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Trichinella Spiralis
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Wucheraria
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a filarial worm (group of parasitic nematodes)
causes elephantiasis in 250 million people worldwide. |
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Life cycle of filarial worms
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-humans are bitten by infected mosquito or flea and contract larva (microfilaria)
-adult Wucheria lives in lymph glands, leadining to dramatic swelling -adult oncocerus lives in cornea causing river blindness -adult dirofilaria live in heart (of mostly dogs (heartworm) |
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microfilaria
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larva of filarial worms (which are carried by blood sucking insects)
(nematode) |
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onchocerciasis
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causes river blindness
vector- blackflies in the tropics a filarial worm (nematode) |
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Dirofilaria
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causes dog heartworm
most common filarial worm in the US. (nematode) can infect canines, cats, sea lions, ferrets,and occasionally humans vector- mosquito up to 45% of dog along Mississippi river valley and Atlantic coast are infected |
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What is the most common nematode in the US human population?
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pinworm
(enterobius) some 30% of children are infected at some point. |
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pinworm lifecycle
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simple- 1 host. they live in lareg intestine
-females migrate to perianal region to lay eggs -host scratches which contaminated bedsheets, clothes |
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How is the life cycle of Necator (hookworm) similar to ascaris (human &pig nematode) and toxocara (dog and cat nematode)?
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hookworm larva pass from bloodstream to lungs, and then to digestive system
-differs because eggs hatch in soil, and juvenile worms penetrate bare feet. Avoid this parasite by wearing shoes. |
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Trichinella Spiralis:
lifecycle and disease... |
causes trichinosis...there is no treatment, but his disease can be avoided by cooking meat.
Trichinella is an intestinal parasite as an adult, but bloodstream carries larva to muscle (instead of gut) where they incyst *painfully* looks like a "Spiral" |
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what parasite causes trichinosis?
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Trichinella Spiralis
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Wucheraria
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a filarial worm (group of perasitic nematodes)
causes elephantiasis in 250 million people worldwide. |
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Life cycle of filarial worms
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-humans are bitten by infected mosquito or flea and contract larva (microfilaria)
-adult Wucheria lives in lymph glandsleadining to dramatic swelling -adult oncocerus lives in cornea causing river blindness -adult dirofilaria live in heart (of mostly dogs (heartworm) |
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microfilaria
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larva of filarial worms (which are carries by blood sucking insects)
(nematode) |
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onchocerciasis
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causes river blindness
vector- blackflies in the tropics a filarial worm (nematode) |
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Dirofilaria
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causes dog heartworm
most common filarial worm in the US. (nematode) can infect canines, cats, sea lions, ferrets,and occasionally humans vector- mosquito up to 45% of dog along Mississippi river valley and Atlantic coast are infected |
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What is the most common nematode in the US human population?
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pinworm
(enterobius) some 30% of children are infected at some point. |
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pinworm lifecycle
(enterobius) |
simple- 1 host. they live in large intestine
-females migrate to perianal region to lay eggs -host scratches which contaminated bedsheets, clothes |
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What parasitic nematode lives just under the skin of the human host and sheds larva directly from an open sore into the water?
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Dracunculus
"the guinea worm" |
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dracunculus (parasitic nematode)
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parasitic nematode that lives just under the skin of the human host and sheds larva directly from an open sore into the water.
Infects human feet and legs. intermediate host is cyclops- a small crustacian |
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How is dracunculus (parasitic nematode) removed?
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tie a string around it and slowly wind it around a stick.
(symbol for medical profession has snake wrapped around a stick) |
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What 3 annelids do we study?
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oligochaeta- earthworms
polychaeta- marine annelids "tubeworms" class hirudinea- leeches |
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What 3 annelids do we study?
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oiligochaeta- earthworms
polychaeta- marine annelids "tubeworms" class hirudinea- leeches |
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annelid repro
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though earthworms and leeches are monoecios, they only reproduce SEXUALLY.
marine tubeworms are dioecious and reproduce SEXUALLY. |
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annelid repro
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though earthworms and leeches are monoecios, they only reproduce sexually.
marine tubeworms are dioecious and reproduce sexually. |
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Which phylum or form has a eucoelom?
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Annelids
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What are the advantages of the Eucoelom over the psuedocoelom (of the nematodes)?
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-allows for segmentation
-segments can move independently increasing efficiency of movement. |
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peritoneum
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-lines the eucoelom
-composed of connective tissue that holds organs in place (mesentaries) -mesodermal origin -found in annelids and higher vertibrates -mesoderm around gut allows for gut muscles. |
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mesentaries
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connective tissue that holds internal organs in place
"glue" -extension of the peritoneum in annelids |
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another word for segmentation?
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metamerism...segments can also be called metameres or somites.
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commonalities between nematodes and annelids?
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-bilateral symmetry
-cephalization -complete digestive track (mouth to anus) -parasitism occurs in both phyla, though in annelids it is restricted to ectoparasitism (leeches) -neither group has a well developed respiratory system -both require moist environments. |
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Differences between nematode and annelid muscles?
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-nematodes have only longitudinal muscles in the body wall; annelids have both longitudinal and circular muscles in the body wall
-annelids have muscles lining the digestive system (gut) -nematodes have a muscular pharynx, but no gut muscles |
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Peristalsis
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waves of expansion and contraction in muscles/segments.
-move body of annelids and push food through gut. |
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differences between nematode and annelid excretory system?
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nematodes use diffusion and may use excretory canals
-annelids have nephridium...ciliated nephridic tubule is intertwined with capillary network and funnels waste into a sort of "micro-bladder" and out of a NEPHRIDIOPORE. |
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nephridium
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organs which occur in pairs and function similar to kidneys. They remove metabolic wastes from an animal's body.
(PROTOnephridia are found in flatworms- aka flame cells) |
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homoplasy
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genetic relationship is very distant
-similarity due to convergent evolution. (eg: like bat wing and mosquito wing.) |
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homology
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anatomy similar due to evolutionary derivation from common ancestor.
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chlorogogue cells:
description and function |
modified cells of the peritonium covering the digestive system
-convert waste products of protein to ammonia and urea and synthesize glycogen and fat from excess calories. like "liver" stores excess sugars as glycogen...excess after that gets turned into fat. |
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How does the circulatory system of annelids differ from that of nematodes?
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-nematodes don't really have any!
-annelids have a complex CLOSED circulatory system with veins and arteries. |
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open vs. closed circulatory
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open- blood goes into body tissues and surrounds body cells
closed- blood stays in veins |
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annelid "hearts" /circulatory
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multiple "hearts" are aortic arches which regulate blood pressure.
-pumping is done by dorsal vessel. -respiratory pigments often present in blood (like "hemoglobin") |
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annelid respiratory: how does it differ from nematodes?
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-nematodes exchange gases via diffusion
- some annelids have (primitive) gills...esp marine forms (*there are pictures of these external gills- some look like flowers.) BUT earthworms and leeches have no specialized resp sys...use DIFFUSION. - |
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How does the nervous system of annelids (segmented worms) differ from that of nematodes (roundworms)?
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-nematodes have BOTH dorsal and ventral nerve cords.
- annelids have only a ventral nerve cord connected to a dorsally located cerebral ganglia via 2 CIRCUMPHARYNGEAL connectives. -and each segment (somite) has a pair of ganglia |
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setae
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bristles on annelids.
eg. help earthworms to attach to the surface and prevent backsliding during peristaltic motion. |
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oligocheata
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means "few setae"
soil & freshwater annelids with small & few setae. Earthworms. |
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Representative member of oligochatea?
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Common Earthworm
Lumbricus terrestris |
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digestive system of an earthworm?
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mouth-> pharynx-> esophagus-> Crop (soft)-> Gizzard (firm)-> Gut
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oligochaete sex
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(earthworms)
monoecious, but DON"T self fertilize. Have large CLITELLUM - lay opposite eachother and exchange sperm into receptcle. CLITELLUM picks up eggs and sperm and deposits them into a cocoon. |
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Direct development
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no larval stage, as in oligochaetes (earthworms)
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What is the ecological niche of earthworms and how important are they ecologically?
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They are DETRITIVORES enormously important in the cycling of nutrients.
-freshwater forms feed fish. Darwin referred to earthworms as the "intestines of the soil." |
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Polychaeta
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-marine annelids
-literally "many setae" (bristles) -aka "tubeworms" -a predator in marine ecosystems -pronounced external cephalization |
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representative polychaete known as "clamworm" or "Sandworm"?
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Nereis Virens
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parapodia
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fleshy "sorta feet"
-extensions of each somite of a POLYCHAETE. |
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Polychaete reproduction?
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Dioecious
-no permanent sexual organs -indirect development (TROCOPHORE larva) |
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annelid ectoparasite?
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Hirudinea
-the leeches |
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hirudinea
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ectoparasite annelid...lecches.
-FRESHWATER -predator of invertibrates, parasite if vertibrates. -segmented, without setae -anterior, and posterior sucker right next to anus. (as opposed to flukes' ventral and anterior suckers) |
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How are hirudinea (leeches) different from fellow annelids?
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-no setae
-no internal septa -modified coelom filled with connective or chlorogogue tissue. -some have modified CLOSED circ. system. (veins, arter,capill) -digestive system modified for fluid feeding. |
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Hiudinea (leech) reproduction?
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Monoecious
-direct development -4-12 pairs of testes, and 1 pair of ovaries |
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medical use of leeches: past and present?
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-Hirudo medicinalis was used for blood letting which was thought to cure disease.
-they are now used in microsurgery to relieve wound congestion and help reattach severed blood vessels. |
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Annelids, mollusks and arthropods were all thought to be closely related...what does modern RNA testing indicate?
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Arthropods may not be closely related to the 2 other groups.
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What subphyla of arthropods did we study?
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1. Trilobita
2. Chelicerata (arachnids and meristomata- horseshoe crabs) 3. Crustacea (crabs, lobster, crayfish) 4. Unirania (centipedes, millipedes, insects) |
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What are the formal class names for:
1. centipedes 2. millipedes 3. insects |
1. Chilopoda (lip foot?)
2. Diplopoda (means double foot, referring to 2 pairs of legs per segment) 3. Insecta |
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class name for horseshoe crab?
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meristomata
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advantages and disadvantages of exoskeleton in arthropods?
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cuticle protects against chemicals, disease and dehydration
- must be molted 4-7 times before adulthood (it's not alive so does not grow) |
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What do we call the "suit of armor" with flexible joints that is excreted by the epidermis in arthropods?
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CUTICLE
*also GREAT for protecting against dehydration. *cuticle of crustaceans is impregnated with calcium salts |
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Tough resistant nitrogenous polysaccharide which is insoluble in water, alkalies or weak acids:
(found in arthropods) |
chitin
*forms exoskeleton |
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6 reasons for arthropod success:
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exoskeleton
segmentation air piped directly to cells highly devel. sensory organs complex behavior patterns limiting intraspecific competition through metamorphosis |
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How does metamerism differ between arthropods and annelids?
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-more advanced in arthropods
-considerable fusion and reduction of segments in adult stages -some segments are extensively modified for sensory functions, food handling, walking, swimming, etc. (In malacostraca thorax is 13 fused segments...eg. lobster) |
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anatomy of arthropod appendages?
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-they are jointed
-each jointed part consists of a hollow lever moved by internal muscles -*this arrangement gives them GREAT strength. (a human would have to jump 600 feet to compete with the jump of a flea) |
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Respiratory in TERRESTRIAL arthropods?
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Air is pumped directly to cells!
-highly efficient tracheal system which delivers oxygen directly to the tissues and cells and makes a high metabolic rate possible. |
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What is the disadvantage of the tracheal system in terrestrial arthropods?
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Air being pumped directly to cells has a SIZE LIMIT.
difficult to do in a large body- can't diffuse O2 very far. |
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Respiratory in AQUATIC arthropods?
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GILLS attached to bases of walking legs (like the crayfish)
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Sensory organs in arthropods?
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-arthropods are keenly aware of what is happening in their environments.
3 examples: -compound eyes of insects/crustacea -sound communication in grasshoppers (tympanium) -antennae of silkworms (senses pheromones) |
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tympanium
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a grasshopper's "ear"
*like tympani musical instrument :) |
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which phylum was first to develop communication via sound?
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arthropods
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How does the antennae work in silkworm moths?
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female releases pheromones and males locate the females by following concentration gradient (for mating).
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example of complex behavior patterns in arthropods?
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honeybee dance.
(highly organized behavior in social insects.) |
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How do arthropods limit intraspecific competition?
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METAMORPHOSIS
-larva and adult do not compete for resources. 2 kinds: homometabolous (complete change) and hemimetabolous (half change) |
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2 kinds of metamorphosis?
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HOMOmetabolous (complete change, as in butterfly)
HEMImetabolous (half change, as in beetle-like nymphs growing into beetle) |
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Nervous system in arthropods?
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(basic layout similar to annelids)
-ventral nerve cord and dorsally located cerebral ganglia with CIRCUMESOPHOGEAL connectives. BUT complexity of nervous system is considerably advanced in terms of behavior (innate and learned). |
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excretory and osmoregulatory system in AQUATIC arthropods?
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-crustaceans have gills through which nitrogenous wastes are lost via DIFFUSION and ANTENNAL (or green) GLANDS for osmoregulation- composed of bladder and labyrinth.
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excretory and osmoregulatory system in TERRESTRIAL arthropods?
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MALPIGHIAN tubules
like kidneys and make uric acid (solid & liquid waste together, like bird poop :)) *most efficient of ANY animal- that's why they can thrive in desserts. |
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Circulatory system of aquatic arthropods?
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Open- like in the crayfish.
Heart & arteries, but no veins. -No separation of blood from interstitial fluid. |
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Circulatory system of terrestrial arthropods?
(such as insects and spiders) |
single dorsal vessel is only blood vessel.
IT pumps hemolymph, but has little to do with the transportation of oxygen (because of arthropod tracheal system). |
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What is the name of the primitive type of flight muscles in insects?
(such as dragonflies and grasshoppers) |
DIRECT flight muscles.
-SYNCHRONOUS NERVOUS CONTROL *each wing stroke is initiated by a nervous impulse |
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What is the name of the advanced type of flight muscles in insects?
(true flies, gnats, bees, etc) |
INDIRECT flight muscles.
-ASYNCHRONOUS NERVOUS CONTROL *Many wing beats are initiated by a single nervous impulse, which makes rapid wing beats possible. *it pulls top of body down as wings go up and takes advantage of RECOIL energy. |
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What type of pattern do insect wings move in as they fly and why?
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Figure 8...
It generates forward thrust. |
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How far and fast do monarch butterflies travel?
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during fall migration 2K miles at 6 mph. (from canada to central Mexico) &can go 621 miles without stopping!!
*desert locust flies 2800 miles yearly. |
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speeds of insects:
horse fly dragonfly tabanid fly |
horse fly -30 mph
dragonfly -25 mph tabanid fly -90 mph * and fruit flies can beat their wings a1000 times/second!! |
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What are the different mouthparts insect have, and give example species of each.
Which type is the most primitive? |
-BITING/ CHEWING mputhparts. eg: grasshopper *most primitive!
-SUCKING piercing mouthparts. eg: mosquito, butterlfy -SPONGING/ LAPPING mouthparts eg: housefly *some insects COMBINE these, such as the horsefly with both biting and lappingmouth parts. Damn them. |
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Grasshopper mouthparts: top to bottom.
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-right and left mandible
-right and left maxilla with maxilary palp -labium (like upper lip) -labium with labial palps *in general "palp" means mouthpart |
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Evolutionary relationship between arthropods and annelids?
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not clear.
Used to think that arthropods evolved from annelids, but molecular evidence doesn't support this idea. |
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What SUBPHYLUM includes the horseshoe crabs, trilobites and arachnids?
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Chelicerata
-they posses CHELICERAE which means "claw horn"...the first pair of head appendages/mouthparts |
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What class do the horseshoe crabs belong to?
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Merostomata
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Which chelicerate has primitive chelicerae which look very similar to the walking legs? (actually all legs similar/less modified)
What is the name for this primitive condition? |
horseshoe crabs (merostomata)
UNDIFFERENTIATED APPENDAGES *crustacean appendages are highly modified from this plan. |
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Horseshoe crab's larva?
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is called trilobite larva.
Looks very similar to extinct trilobites, to which they may be related. |
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horseshoe crab respiration?
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BOOK gills.
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Telson
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horseshoe crab's tail...used for balance.
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horseshoe crab feeding?
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*GNATHOBASE
The mouth is a strange, alien looking structure: gnathobase. -located on the underside of the body right at the base of all the walking legs. It is surrounded by dozens of thin spines which point inward. It cannot swallow its food unless its legs are moving. The base of the legs are basically needed for chewing. |
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eyes of trilobite?
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almost "perfect"
they can see 290 degrees around (that's 4/5 of the way around) |
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CLASS containing mites, ticks, spiders, scorpions
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Arachnida
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How are chelicera modified in arachnids?
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Used to kill prey and kill food source.
*some spiders have poison fangs. |
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pedipalps
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Paired head appendages used as legs, pincers or feelers.
They have chewing parts at the base. |
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Sexual dimorphism in spiders?
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Males are often smaller and have specialized pedipalps used in sperm transfer.
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2 major parts of a spider's body?
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cephalothorax and abdomen
(fusion of head & thorax and of abdominal segments) |
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how many eyes and legs on an arachnid?
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8 of each
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spider reproduction
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-male spins small web and deposits sperm which is then sucked into modified pedipalps
-male courts female with ritualized movements and inserts pedipalp into genital opening of female - male gets out fast or is EATEN! |
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How many spiders occur in an undisturbed field?
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up to 2 million/acre.
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Ecological importance of spiders?
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major control for insect pests
estimate that the weight of insects eaten by spiders in Great Britain is equal to the weight of humans in Great Britain. |
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Why do spiders enter houses?
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There are BUGS in our houses!
Spiders eat them! |
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2 bad spiders?
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BROWN RECLUSE- violin spider- has violin shaped making on cephalothorax. NECROTIC
BLACK WIDOW- red hourglass on botton, and shiny black round abdomen. NEUROTOXIN potent, but use small amounts, so not usually fatal |
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How do scorpions differ in structure from spiders? (both arachnids!)
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scorpions have short cephalothorax, preabdomen, and postabdomen (5 segments each).
Postabdomen ends in stinging TELSON. Scorpions have small chelicerae, but large pincer-like pedipalps. |
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quirks of scorpion repro?
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-elaborate mating dance
-females carry young |
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How harmful are scorpions?
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Most AREN'T.
Only a few in Mexico and Africa. |
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Order ACARI?
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mites and ticks:
The most economically and medically important group of arachnids! Subphylum-Cheliceratae Class-Arachnid |
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How many known species of Acari (order to which mites and ticks belong)?
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As many as 1 million!
30K have been described. |
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Why are Acari (mites and ticks) so medically and economically important?
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-Many are parasitic during 1 or more stage of life cycle.
-Some are very serious agricultural pests (most are free-living) |
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How do ticks differ structurally from other arachnids?
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Complete fusion of cephalothorax and abdomen.
-No sign of external metamerism. -all larval ticks and mites have 3 pairs of legs and some specialized forms have 3 pairs as adults (but most adults have 4 pairs). |
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How to identify deer ticks?
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small size, orange color
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Seriousness of Lymes?
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Chronic and disabling with arthritis symptoms.
-most people don't get the disease or recover spontaneously. -common in dogs, so should be vaccinated. |
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What member of the Acari caused serious damage to ag crops such as clover, cotton, fruit trees, etc?
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Spider mites.
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mite larvae that cause dermatitis, transmit disease and cause mange?
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Chiggers
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Aquatic arthropod subphylum (with relatively hard shells)?
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Crustacea
(we aren't responsible for classes of this subphylum) |
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Ecological importance of Crustaceans?
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-The most abundant animal in the world are probably COPEPODS (greek: fastened foot) of the genus CALARUS...present in many ecosystems.
-Also Krill is the foundation of the food web that includes great whales and other marine creatures. |
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crustacean body plan: what is unique?
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-They are the only arthropods with 2 PAIRS of antennae.
-Cephalothorax and segmented abdomen -1 pair of appendages per segment, but highly modified to serve different functions |
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Malacostraca (crab, shrimp, lobster, etc) appendages beginning from anterior to posterior:
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1-Rostrum (the foremost extension of a crustacean's carapace.)
2. eye 3.antennule (2 antennae, fused at bottom) 4. Antennae (long) 5. mandible (mouthparts) 6.Maxillae (2) (mouthparts) 7.Maxillipeds(2) (mouthparts) 8.Cheliped (claw/first walking leg) 9. Walking legs (4) 10. Swimmerets(5) 11.Uropod (attached to telson) |
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Digestive system of crustaceans?
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crushing mandibles-> esophagus-> cardiac stomach (with gastic mill)-> pyloric stomach-> intestine
*cardiac is chemical stomach, pyloric is crushing stomach. |
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Gastrolith
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rock-like, in lining of crustacean stomach. It leaches out of shells during molting, but is then disintegrated back into animal to help form new shell.
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Crustacean development:direct or indirect?
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INDIRECT with a true larval stage.
*most common larva is NAUPILUS |
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sessile monoecois filter feeding crustaceans?
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BARNICLES!
**They have jointed appendages, so they can't be mollusks. Cypris larva. These animals can increase the drag of ships 30-40% and are expensive to scrape off! |
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1 of few crustaceans to inhabit terrestrial ecosystems?
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isopods (pillbugs)
They lack a cuticle (dehydrate) so they must live in moist locations. |
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group of crustaceans that include crabs, lobsters, crayfish, etc?
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Decapods
(means "10 feet") after 5 pair walking legs, and 5 pair swimmerets. |
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unique thing some crustaceans (especially crabs) do.
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camouflage themselves using materials from their surroundings (like sponge crab)
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size range in crustaceans?
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few mm to 4 meters (about 12 feet...the chelae appendages reach that far)
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importance of crustaceans economically and ecologically?
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important as a food source and important in many marine ecosystems. (like the one a block from my house!)
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Which subphylum includes the insects, centipedes and millipedes?
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Uniramia (means "one branch")
Classes Chilopoda (centipedes) and Diplopoda (millipedes). |
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Describe centipede (chilopoda) body plan.
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-head bearing 1 pair antennae, 2 pair maxillae and...
- the first pair of legs are modified into MAXILLIPEDS with POISONOUS fangs. -similar segments with 1 pair of legs per segment. -somewhat flattened segments -fast moving predators -live in moist places. *some centipedes are big enough to eat small mammals, even rats! |
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millipede body plan.
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-head bears a pair of antennae, mandibles and maxillae
-2 pairs of short legs per segment -slow moving -herbivores -prefer dark moist places. -curl up and protect themselves by secreting toxic fluids from REPUGNATORIAL glands. |
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pill bugs: which subphylum?
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CRUSTACEA! they seem like uniramians, but aren't!
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longest millipede?
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.38 meter!!
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How do insects (insecta) differ from centipedes and millipedes?
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Head, thorax and abdomen
-All with wings, except for a few primitive and highly specialized types, like fleas and lice |
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Ecological importance of insects?
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-Every feeding type: herbivores, predators, parasites, detritivores
-in virtually all freshwater and terrestrial habitat -important to human as pollinators, predators, crop and forest pests, disease vectors, honey producers, recyclers, prey for vertibrates, etc. |
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Dominant terrestrial animals?
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Insects!! (lots of niches)
-1/3 of all animal species are beetles- over 300K! some scientists estimate that for every human there are 200 mill insects! |
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Which classes have TROCOPHORE larva?
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-Polychaetes
-Most mollusks, except gastropods and cephalopods |
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Cypris larva- what class?
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barnacles
(cirripedia) |
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Naupilus larva- which subphylum?
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crustaceans
(most common crustacean larva) |
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trilobite larva- what class?
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horseshoe crab (merostomoata)
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miracidium larva- what class?
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Trematodes (flukes/endoparasites, from phylum nematode)
*develops into SPOROCYST where REDIA develop |
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microfilaria larva- what family?
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filarial worms
*these larva are carried by blood-sucking insects. |
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vector for:
1-wucheria (elaphantiasis) 2. ascaris 3. clonorchis (liver fuke) 4 necator |
1. biting INSECT
2. unwashed FOOD, unsanitary 3. uncooked FISH 4. juveniles penetrate FEET |
