Invert exam 2 PDF

Preview

Summary

Complete notes for invertebrate zoology exam 2 with Dr. Christensen. study and memorize this and you will make an A. ...

Description

Phylum Platyhelminthes Class Cestoda a Tapeworms b Endoparasites of vertebrate digestive tracts i Have no digestive system ii Absorb the nutrients they need across their body wall 1 Tegument with microtiches (increase surface area)

2 iiiUse intermediate hosts

c May be meters in length d Anterior attachment organ i Scolex: attachment 1 Hooks and suckers e Body divided into proglottids i Neck & strobilation ii Contain both male and female gonads iiiThe further down, the older the proglottid ivCan self fertilize v Older proglottids break off and leave via feces viEggs/larvae are eaten by intermediate host 1 Eaten by flea and flea ingested by pet and it has worms Eaten by cow and human eats meat and is infected Phylum Xenocoelomorpha: f Recently made a phylum gSmall, acoelomate marine flatworms

h Incomplete gut & midventral mouth i Pulsatile bodies i Masses of ciliated cells being phagocytosed j Anterior statocysts kDifferent cilia i Arrangement of microtubules l Longitudinal and circular muscle only m Based on molecular evidence n 2 subphyla i Acoelomorpha ii Xenoturbellidae o Subphylum Acoelomorpha i Class Acoela (no coelom) 1 No permanent digestive cavity Syncitium that phagocytosizes particles Some have symbiotic algae 2 Simple pharynx 3 Completely covered in cilia 4 Anterior statocyst with one statolith 5 No protonephridia (flame cells) 6 Bi-flagellated sperm 7 Direct developers 8 Hermaphrodites ii Class Nemertodermatidae

iii 1 2 3 4 5

Few dozen species Free living in sediment Anterior statocyst with two statoliths Epidermal cells connected to underlying muscle Have an incomplete gut No pharynx Have space

Mouth is transient May have broom organ Used in food gathering 6 Auto sperm & allosperm (can see difference) Both can fertilize their egg (self fertilization can happen) Auto sperm Sperm that they make in their own body Allosperm Sperm that they’ve been impregnated with Mesozoa (middle animal) pMulticellular i 10-40 cells qNeither diplo- or triploblastic i 2 tissue layers ii Ectoderm & mesoderm r All parasites s Outer surface ciliated t Gametes and embryos develop intracellularly uMay be early branch or degenereate i Lophotrochozoa ii Multicellular protist v Class Rhombozoa i Dicyemida

ii iii iv v

vi 1 2

3 vii 1 2 viii 1 2

65 species Obligate symbionts of nephridia of cephalopod molluscs Both sexual and asexual reproduction Primary nematogen

20-30 ciliated cells (outside) Axial cell (inside) One central big cell where gametes are formed Jeuviniles free swimming Axoblast Develops inside axial cell Becomes new nematogens Rhombogen Sexual stage Axoblasts form infusorigens Non-ciliated structres retained in rhombogen Simultaneous hermaphrodites Egg & sperm form infusoriform larvae

Leaves host ???- unsure of other stages ix

w x Class Orthonectida i 20 species ii Parasites in gonads 1 Bivalve molluscs, polychaetes, turbelarians, and echinoderms 2 Castrate host iii Asexual forms dominate 1 Plasmodial stage Juvenile 2 "adults" form in plasmodium (big syncytial structure) Both make and female Exit plasmodium and host Internal fetrilization

iv

Phylum Nemertea (ribbon worms): y Multicellular i 10-40 cells z Neither diplo- or triploblastic i 2 tissue layers ii Ectoderm & mesoderm aa All parasites bb Outer surface ciliated cc Gametes and embryos develop intracellularly dd May be early branch or degenereate i Lophotrochozoa ii Multicellular protist ee Class Rhombozoa i Dicyemida ii 65 species iii Obligate symbionts of nephridia of cephalopod molluscs iv Both sexual and asexual reproduction v Primary nematogen

vi 1 2

20-30 ciliated cells (outside) Axial cell (inside)

3 vii 1 2 viii 1 2

ix

One central big cell where gametes are formed Jeuviniles free swimming Axoblast Develops inside axial cell Becomes new nematogens Rhombogen Sexual stage Axoblasts form infusorigens Non-ciliated structres retained in rhombogen Simultaneous hermaphrodites Egg & sperm form infusoriform larvae Leaves host ???- unsure of other stages

ff gg i

Class Orthonectida 20 species

ii 1 2

iii 1 2

iv

Parasites in gonads Bivalve molluscs, polychaetes, turbelarians, and echinoderms Castrate host Asexual forms dominate Plasmodial stage Juvenile "adults" form in plasmodium (big syncytial structure) Both make and female Exit plasmodium and host Internal fetrilization

Phylum Gnathifera (the jaw): hh All have pharyngeal jaws i Similar ultrastructure ii Formerly with Aschelminthes i Split into 2 groups 1 Gnathifera 2 Cyloneuralia- molt (exoskeleton has to be shed in order for them to get bigger) jj Psuedo- or blastocoel i Has body cavity that’s not fully lined with mesoderm kk Eutely i Fixed number of cells (all have same number of cells no matter the species) ll Syncytial epidermis F Phylum r s

Rotifera

t u v A B C A B w A A B x A y A z aa bb A B C A B C

"wheel bearer" Defining characteristics Muscular pharynx with jaws Toes with adhesive glands Ciliated corona (wheel organ located anteriorly) Most species have this Used for locomotion and feeding 1,850 species 95% freshwater Interstitial (live between sediment grains) Marine and semiaquatic (live in a habitat that has a film of water like moss) Intracellular cuticle Not molted (shed) Most are free living Solitary and colonial Most omnivorous both smooth and striated muscle 3 body sections head trunk foot 1-4 toes (depending on the species) pedal glands may be used for locomotion or

attachment cc A B C dd A ee A ff A B A C gg A B hh A B G r s t u A A

corona trochus cingulum used for feeding and locomotion mastax muscular pharynx with teeth (trophi) complete digestive system gastric glands bilobed brain two longitudinal nerve cords sensory bristles (flosculi) chemosensory and mechanosensory ocelli protonephridia and bladder osmoregulation nitrogenous waste diffuse across body wall specializations cryptobiosis (hidden life) lorica (outer tube-like coating around them for protection) Reproductive Strategies sexual: male and female, internal fertilization parthenogenesis: asexual; female only mix between the two (Monogononta) types of eggs seasonal/environmental cues

B A B C A B A C A

amictic egg (non-mixing egg, asexual, diploid, 2n) 2n by mitosis (double of all of the chromosomes) parthenogenesis (no males) mictic egg (mixing eggs) 1n by meiosis (haploid) unfertilized becomes male (a haploid male) will produce sperm resting diapause eggs (waits until conditions are good) fertilized egg (2n)

H

Phylum Acanthocephala

r A B s t A u v A A B B C

“thorn”, or “prickly-head” defining characteristics 1-2 ligament sacs, supporting the gonads adults have proboscis with intracellular hooks 1200 species all parasitic in vertebrate guts use arthropods as intermediate hosts may be rotifers?? Extremely closely related three body parts proboscis hollow & retractable hooks and spines neck trunk

spine-”,

A w x y A A B A B

C C

pseudocoel/blastocoel (has a body cavity not fully lined with mesoderm) no digestive, excretory, circulatory systems reduced sensory structures reproduction mostly gonad ligament sacs separate sexes, not hermaphrodites internal fertilization males: cement gland (once he transfers his sperm over, he shuts the female closed) females: ovarian balls & uterine bell (they don’t really have an “ovary” acanthor larvae

I Phylum Gnathostomulida r

s

t

J r s t u v w

A x y

A

“jaw mouth” related to the rotifers 80 species wormlike marine sediment acoelomate outer surface ciliated cells have single cilium incomplete digestive system simultaneous hermaphrodites internal fertilization

B

direct developers

K Phylum Micrognathozoa r single species A Limnognathia maerski s two-part head with complex series of jaws t ciliated epidermis A Cells have multiple cilia u posterior adhesive structure v only females parthenogenesis? 3 Uncertain Phyla: mm i nn i 1 2

All have pharyngeal jaws Similar ultrastructure Formerly with Aschelminthes Split into 2 groups Gnathifera Cyloneuralia- molt (exoskeleton has to be shed in order for them to get bigger) oo Psuedo- or blastocoel i Has body cavity that’s not fully lined with mesoderm pp Eutely i Fixed number of cells (all have same number of cells no matter the species) qq Syncytial epidermis

L Phylum r s

Rotifera

t u v A B C A B w A A B x A y A z aa bb A B C A B C

"wheel bearer" Defining characteristics Muscular pharynx with jaws Toes with adhesive glands Ciliated corona (wheel organ located anteriorly) Most species have this Used for locomotion and feeding 1,850 species 95% freshwater Interstitial (live between sediment grains) Marine and semiaquatic (live in a habitat that has a film of water like moss) Intracellular cuticle Not molted (shed) Most are free living Solitary and colonial Most omnivorous both smooth and striated muscle 3 body sections head trunk foot 1-4 toes (depending on the species) pedal glands may be used for locomotion or

attachment cc A B C dd A ee A ff A B A C gg A B hh A B M r s t u A A

corona trochus cingulum used for feeding and locomotion mastax muscular pharynx with teeth (trophi) complete digestive system gastric glands bilobed brain two longitudinal nerve cords sensory bristles (flosculi) chemosensory and mechanosensory ocelli protonephridia and bladder osmoregulation nitrogenous waste diffuse across body wall specializations cryptobiosis (hidden life) lorica (outer tube-like coating around them for protection) Reproductive Strategies sexual: male and female, internal fertilization parthenogenesis: asexual; female only mix between the two (Monogononta) types of eggs seasonal/environmental cues

B A B C A B A C A

amictic egg (non-mixing egg, asexual, diploid, 2n) 2n by mitosis (double of all of the chromosomes) parthenogenesis (no males) mictic egg (mixing eggs) 1n by meiosis (haploid) unfertilized becomes male (a haploid male) will produce sperm resting diapause eggs (waits until conditions are good) fertilized egg (2n)

N

Phylum Acanthocephala

r A B s t A u v A A B B C

“thorn”, or “prickly-head” defining characteristics 1-2 ligament sacs, supporting the gonads adults have proboscis with intracellular hooks 1200 species all parasitic in vertebrate guts use arthropods as intermediate hosts may be rotifers?? Extremely closely related three body parts proboscis hollow & retractable hooks and spines neck trunk

spine-”,

A w x y A A B A B

C C

pseudocoel/blastocoel (has a body cavity not fully lined with mesoderm) no digestive, excretory, circulatory systems reduced sensory structures reproduction mostly gonad ligament sacs separate sexes, not hermaphrodites internal fertilization males: cement gland (once he transfers his sperm over, he shuts the female closed) females: ovarian balls & uterine bell (they don’t really have an “ovary” acanthor larvae

O Phylum Gnathostomulida r

s

t

P r s t u v w

A x y

A

“jaw mouth” related to the rotifers 80 species wormlike marine sediment acoelomate outer surface ciliated cells have single cilium incomplete digestive system simultaneous hermaphrodites internal fertilization

B

direct developers

Q Phylum Micrognathozoa r single species A Limnognathia maerski s two-part head with complex series of jaws t ciliated epidermis A Cells have multiple cilia u posterior adhesive structure v only females parthenogenesis? Phylum Mollusca: rr i ss tt i uu i

One of the best known groups Clams, snails, octopus, squid All habitats Approximately 100,000 living species 70,000 fossil forms Eucoelomate and bilateral Coelom limited to small spaces around nephridia, heart and intestine vv Unsegmented ww Protostome- have spiral indeterminate cleavage xx Viscera concentrated dorsally- internal organs i Visceral mass yy Defining characteristics i Mantle: epithelium that covers body 1 Secretes calcareous (CaCO3) spicules or shell CaCO3 in protein matrix

2

ii 1

2 iii zz i ii iii

Three layers: periostracum (outer), prismatic (middle), nacreous (inner)- makes pearls (anything that comes into the shell) Mantle cavity houses ctenidia (gills), osphradium (chemo sensory), anus & nephridiopores (rid the body of waste products) Radula: cuticular band of teeth

Odontophore: helps push it forward Ventral muscles develop into "foot" Open circulatory system Tissues come in direct contact with blood instead of blood vessels- hemocoel Heart composed of 2 atria and a ventricle Respiratory pigment

1 2

Hemoglobin Hemocyanin (most common)- copper based pigment (blue)

iv aaa

i bbb Well developed nervous system ccc Complete gut i Regional specialization (allows for differential processing and more areas for absorption) 1 Digestive glands which secretes digestive enzymes used to break down materials ddd Well developed osmoregulatory system i Large complex metanephridia (similar to kidney's)

1

Part of the heart-kidney complex Uses the pressure of the blood coming out the heart Podocytes in the atria (cells that form a filtration system by wrapping around blood vessels, forcing molecules across the membrane) Ultrafiltration Nephrostome open to pericardium (sac that surrounds the heart) eee Trochophore larvae i Similar to Annelids ii Instead of turning into a Polychaeta, it turns into a Veliger fff 7 classes RClass Aplocophora r

s Worm like t No shell A Calcareous spicules or scales u Rudimentary mantle cavity (posterior) A Greatly reduced v Foot reduced or absent w Close relatives of chitons S T Class Monoplacophora r Single, cap-like shell s

U

r s

Very primitive

A t u A

Neopilina Deep sea Have repeated pairs of organs 3-6 pairs of ctenidia (gills), 3-7 pairs of metanephridia, 2 pair of gonads, 2 pairs of atria

v VClass Polyplacophra r Chitons A 800 species

B s t A u v A w A x y z

Flattened and elongated Only found on hard substrates Many intertidal 8 overlapping dorsal plates (valves) Mantle forms thick girdle May obscure the plates Broad ventral foot Pedal waves to move Mantle encircles foot 6-80 pairs of ctenidia 1 pair nephridia

aa

No eyes, tentacles, or crystalline style (part of digestive system) Sugar glands (secretes digestive enzymes)

bb W XClass Gastropoda r "stomach foot"

s t u A v w A B

x y

Snails and snugs Largest class 75% of species (60,000) All habitats (some can live in the desert) Muscular creeping foot Pedal waves Monotactic (move back to front) vs. ditactic (one piece can move separately from the other piece) Head with statocysts, eyes and tentacles Complex radula (feeding structure used to grasp food) and crystalline style (part of digestive

z A B C aa A

B C A B bb A

system that helps to release digestive enzymes Mantle cavity Ctenidia (gills) Osphradia- chemosensory structure Hypobranchial gland Asymmetrical coiled shell Operculum- used to close the opening (aperture) of their shell so that other things can't harm it Columellar muscle- attaches the snail to the shell Reduction of right-side organs in order to retract into the shell Dextral - shells open to the right Sinestral- shells open to the lef Torsion

B C A

D A E F G A A B C A cc A B

dd A

Only in gastropods rotation of the body 90-180 degrees during development Adaptation to living in the coiled shell and allows it to move on sofer substrates and not harm the gills Mantle cavity moves anterior Posterior is now located above the head Gut and nervous system is twisted De-torsion (untwist at some point) Avoidance of fouling Hole in shell Weakens it (things can peak through the hole) Mantle folded to make siphon (snorkel like tube) Change water flow direction Lef (gill & osphradium) to right (anus) Herbivorous or predatory Herbivores eat algae Predators use their radula to cut through other shells and some have poisonous radulas with neurotoxins (strong enough to kill humans too) Subgroups Prosobranchia: typical gastropod (have all the features)

B

A B C D A C A A

ee A B

A B C

Ophistobranchia: pteropods (swimming [pelagic] snails- sea angels), nudibranchs De-torsion or incomplete torsion Shell reduced or absent Rhinophores Reduction/loss of ctenidia (gills) Cerrata (help increase surface area for gas exchange) Pulmonata: "lung" snails Lost gills entirely Pneumostome: specialized opening of the mantle cavity space used like a lung Reproduction Prosobranchs are diecious (separate sexes) Opistobranchs and pulmonates are hermaphrodites (exchange gametes frequently) Reciprocal insemination Internal fertilization Hatch as veligers or direct developers (nudibranchs)

ff Y Class Scaphopoda r Tusk shells s

t u v w

All marine 400 species 1cm- 10 inches Lack gills, heart, and circulatory system, and osphradium All live in sand or mud Feeding tentacles- captacula Deposit feeders of sediment

x y A z Z Class Bivalvia (Pelecypoda- hatchet foot) r

s A t u

Shell comes in 2 halves (valves) Clam shells Clams, oysters, mussels, scallops 9,000 species

v w x y A z aa bb cc A A B

Marine and freshwater Lack of cephalization (NO head) Large mantle cavity Sedentary Some attach to their substrate Absence of radula Eyes along the edge of mantle Lateral compression of body Shell Hinged dorsally Hinge ligament- causes the valves to open when muscles are relaxed

B A B

Umbo Oldest part of the shell

C D C dd ee ff A B C gg

Each ridge is new growth Always points towards the anterior end 1-2 adductor muscles - close the valves Foot is anterior Gill is posterior Water enters and leaves posterior via siphons Modified mantle Incurrent (bottom)- brings water in Excurrent (top)- brings water out...