Mega-Group Protozoans (Protist) - unicellular eukaryotes lacking collagen and chitinous celle walls; all nonphotosynthetic in primitive condition * Alveolates – possess distinctive membrane bound sacs * Ciliphorates – all individuals possess 1 micronucleus and 1 macronucleus * Dinoflagellates – bears 2 structurally distinct flagella; bioluminescence; flagella beat in patter, ‘whirl’ * Apicomplexa – endo parasitic (needs vectors); adults sessile * Flagellates – possess 1 or more flagella * Euglena * Amoebozoa – nearly all possess branching tubular mitochondrial cristae * Gymnamoebae – heterotrophic; shapless bodies; (fingerlike) pseudopodia; eats phagocytosis * Eumycetozoa – acellular slime mold forms plasmodium, cellular slime mold forms pseudoplasmodium; loss nutrients stimulates forming sporangia; * Xenophyophoreans – deep marine organisms; cement foreign particles to form test; largest known protists * Group Rhizaria – forms a test (hard covering) from CaCO3, silica, or strontium sulfate * Phylum Foraminifera – test formed from CaCO3; primarily marine * Phylum Radiolaria – test formed from silica or strontium sulfate; planktonic organisms; have axopodia;
Phylum Placozoa – multicellular; amorphous; mobile (flagella); external digestion (no body cavity/mouth); asexual (budding); embryos formed (no use, never fertilized/hatched)
Phylum Porifera - have choanocyte, spicules, and archeocyte; lack nerves, organs, and anterior, posterior, or oral surfaces * Class Calcarea – spicules made of calcium carbonate; asconoid (simplest body type) * Class Hexactinellida – support from spicules made of silica and chitin; symmetrical; either synconoid or leuconoid (body type) * Class Demospongia – largest class poriferans; almost all leuconoid (body type); spicules and fibers made from spongin and/or silica; contractile vacuoles;
Phylum Cnidaria – 1 opening for food in/out and reproduction tract; 2 distinct body forms: medusa and polyp; secretion complex intracellular organelles called cnidae (nematocysts) * Class Scyphozoa – Mesoglea thick and gelatinous (true jellyfish); * Order Semaeostemeae – contact w/oral arms or tentacles = gives sting; * Order Rhizostomeae – many small mouths opening into complex canal system; * Class Cubuzoa – medusa w/boxlike body; rhopalia bear complex, lensed eyes; * Class Anthozoa – absence of medusa stage; mitochondrial DNA circular; all marine; gametes = planula larvae or asexual; primarily carnivorous; * Order Stolonifera – organ pipe coral (only on reefs of tropical indo-pacific) * Order Gorgonacea – mostly tropical; form colonies; supported by firm, central, proteinaceous skeleton of gorgonin; * Order Alcyoncea – ‘soft corals’; in all oceans especially tropics; colonial; lack rigid skeleton but have calcareous spicules embedded in tissues * Subclass Zoantharia – sea anemones; numerous tentacles around mouth opening; many solitary and lack any protective specialized covering * Order Actinaria – sea anemones; no colonial species; * Order Corallimorpharia – worldwide (even at poles); solitary; lack rigid skeleton elements * Order Scleractinia – true ‘stony’ or ‘hard’ corals; forms symbiotic relationships w/unicellular algae; reef building; asexual reproduction (branches break off); * Order Ceriantharia – solitary; living in tubes buried vertically in soft sediments; withdraws into tube if attacked; special nematocysts called ptychocysts; * Order Ptychodactiaria – restricted to cold waters (artic and Antarctic) * Order Antipatharia- black or thorny coral; deep water tropical; skeletal support system composed of chitimous fibers and protein; used for jewelry; * Class Myxozoa – parasitic (mostly fish); extracellular, spore-forming; * Subclass Malacosparea- * Class Hydrozoa – greater representation of polyp form; nematocysts restricted to epidermis (not in gastrodermal tissue) * Order Hydrocorallina –
Phylum Ctenophores – plates of fused cilia arranged in rows; adhesive prey-capturing cells; marine exclusive; bioluminescent; NOT colonial or polymorphic; * Class Tentaculata – has tentacles, mainly for prey-capture * Order Cydippa – long retractable tentacles are well developed throughout life; * Order Lobata – all are planktonic; have aural lobes and auricles * Order Cestida – all are pelagic; found worldwide especially tropics; development = normal, tentacles cydippid which elongates to adult form; * Order Platyctenida – flattened; only in shallow waters in tropics and at poles; reproduce asexually (breaking off body) and sexually; internal fertilization * Class Nuda – no tentacles or oral lobes; well-developed 8 comb rows; muscular lips surrounding mouth (can widen for larger prey); macrocilia inside mouth used as teeth * Order Beroida – in all the world’s oceans (see Nuda for description)
Phylum Platyhelminths – bilateral; triploblastic; simultaneous hermaphrodites; * Class Turbellaria – ciliated; high surface area to volume ratio causes living in aquatic conditions (flatworms); has cerebral ganglion (primitive but distinct brain); * Class Cestoda – endoparasites; simultaneous hermaphrodites; need intermediate hosts; scolox (anterior hooked attachment organ); absence of digestive tract; * Class Monogenea – ectoparasites (fish=host); posterior attachment orgran (haptor) including sucker and complex attachement hooks and sclerites; * Class Trematoda – parasitic; ‘flukes’; body never segmented; ingests host’s tissues and blood through its mouth; * Order Aspidogastreans – never asexually reproduction in host; * Order Digeneans –
Phylum Mesozoa – multicellular; 2 tissue layers: ectoderm and mesoderm; no collagenous connective tissue; parasites on marine invertebrates; body ciliated in some part life cycle; no mouth, digestive system or specialized circulatory, respiratory, sensory, or nervous system; reproductive cells and embryos develop within other cells; * Class Orthonectida – parasitic; gonochoristic (male/female seperates sexes like humans); in host, juveniles form plasmodia in gonad (host=castration); adults leave host (separate sexes), swim in sea, opposite sex sexually reproduce; * Class Rhombozoa – parasitize kidneys and associated structures in cephalopod mollusks; primary nematogen (body=worm shaped), ciliated cells on outer body layer, elongated axial cells form central shaft which is reproductive center (intracellular repro.)(asexual); only develops so many cells then growth from increase in cell size rather than replication; sexual maturation of host can cause next stage called rhombogen (identical to asexual nematogen) and give rise to nonciliated, sexual infusorigens but don’t leave rhombogen, infusorigens simultaneous hermaphrodites but no cross-fertilization (self-fertilize only); nematogen and rhombogen nourishment from urine only; little detriment to host;
SupraPhylum Gnathostomulida – (has Phylums Acanthocephala, Rotifera, and Micrognathozoa) small, soft-bodied, interstitial worms; lives in space b/t sand grains; acoelomate; externally ciliated; triploblastic; have mouth but no functional anus; lack specialized circulatory or respiratory systems; most complex structures = mouthparts, hardened jaws; hermaphroditic; internal fertilize; no free-swimming larvae; * Phylum Micrognathozoa- 2 part head containing highly complex series of jaws; locomote by ciliary activity, double-row ciliated cells; posterior, ventral surface have adhesive ciliary pad; reproduction is parthenogenesis (virgin birth) * Phylum Rotifera- fluid-filled body cavity= pseudocoel; eutely- growth through increased cell size rather than cell #; unable to regenerate lost body parts; pharynx highly muscular and containing jaws (trophi) for grasping, crushing, or grinding prey or attaching to host; toes with adhesive glands * Class Seisonidea- ectoparasites of marine crustaceans; corona reduced in size; reproduction exclusively sexual, individuals have separate sexes; fertilization internal, true copulation or hypodermic impregnation; * Class Bdelloidea- all free-living and mobile; no parasitic species; omnivorous suspension feeders; corona well-developed and bilobed; repro. Exclusively parthenogenesis; all female; live in stressful conditions- polar lakes, etc.; cryptobiosis- state extremely low metabolism; * Class Monogononta- only free-living sessile; found on macroscopic plants, filamentous algae, or tubes of other sessile rotifers; carnivores; ciliation buccal field presumably aids ingestion; live in protective tubes; lorica- cuticle thick and rigid; repro. Parthenogenesis; amictic- prod. eggs w/o ‘mixing’ genes from others; mictic sometimes, produce males, fertilize, resting eggs (developmental arrest), give rise to amictic females; amphoteric * Phylum Acanthocephala- 1-2 large, acellular, collagenous sacs in pseudocoel, supporting gonads; adults w/proboscis containing intracellular hooks; gut parasite in vertebrates; have intermediate host: arthropod; cylindrical; eutely; lack specialized respiratory structures; large pseudocoel; 3 distinct parts: proboscis, neck, and trunk; proboscis have hooks; use hooked proboscis to remain in host; pseudocoel contains gonad and associated glands; gonochoristic; males have cement glands for repro.; no well-defined ovary; ovary fragments forming ovarian balls; internal fertilize; eggs develop in female’s pseudocoel to acanthor stage; exit host in fecal; goes to invertebrate host; can have transport hosts; no trace digestive tract;
Phylum Nemertea- elongated, unsegmented, soft-bodied worms; marine, shallow water environments; only few parasitic; ciliated externally; flattened dorsoventrally; circular, longitudinal, and dorsoventral muscles; cerebral ganglia form ring anteriorly, ladder-like longitudinal nerves; possess pigmented photoreceptors (‘eyes’); digestion intracellular; possess true circulatory system; no true heart; blood does not circulate unidirectionally; one-way digestive tract w/anterior mouth and posterior anus; meat eaters; proboscis-retractable gut usually w/spikes, harpoon, etc.; burrows to hide from predators; gonochoristic or protandric; fertilization external; * Class Anopla- lack stylets, proboscis unarmed; mouth posterior to brain; mouth and proboscis openings separate; * Class Enopla- proboscis may be armed; mouth anterior to brain; proboscis goes through mouth; has terrestrial species
Phylum Mollusca- dorsal epithelium forming mantle, which secretes calcareous spicules or shells; cuticular band of teeth (radula) in esophagus (not present bivalves); ventral body wall muscles develop into locomotory or clinging foot; shells- thin, outer organic layer (periostracum), thin, inner most calcareous layer (nacreous), thick, calcareous middle layer (prismatic); mantle- specialized tissue secretes components and makes shell; has ‘foot’; mantle cavity- between mantle and viscera, houses comb-like gills called ctenidia, exit for excretory, digestive, and repro. systems; ctenidia may function in collection and sorting of food; ospharadium- chemoreceptor/tactile receptor; gills work on countercurrent exchange; coelom very small, restricted to area surrounding heart and gonads; blood sinuses comprising hemocoel (blood cavity) well developed and serve as hydrostatic skeleton for locomotion; radula- firm ribbon, composed chitin and protein, w/2 rows sharp, chitinous teeth; ribbon protected by radular sac; odontophore- supportive cartilage-like structure for radula, radular assembly, w/complex musculature called buccal mass or odontophore complex; old teeth- anterior end, new teeth- continuously formed & added posterior end; usually sexual repro., gonochoristic; fertilization eggs exclusively external (usually); free-living larval stage- have velum but lost in adults; blood circulatory system mostly open; lack specialized oxygen transport pigment; hemocyanin- protein w/copper instead of iron, oxygen-binding capacity of hemocyanin a lot less than hemoglobin; nervous system- depends on activity levels; most have complete digestive system w/ separate mouth/anus; have digestive glands (digestive caeca); have one or more pairs kidneys (metanephridia); * Subphylum Aculifera- calcareous spicules are formed within individual cells in mantle tissue, or in specialized regions of mantle * Class Polyplacophora- (Chitons) shell forms as series 7-8 separate plates; found close to shor,intertidal zone, live only on hard substrates; plates partially or largely embedded in mantle tissue; girdle- thick lateral mantle; most girdle bears numerous calcareous spicules; mantle cavity- 2 lateral grooves, one on each side of body; 80 bipectinate (double-combed) ctenidia hang down from roof each groove; flow water- anterior to posterior, waste discharged posteriorly; countercurrent exchange; foot along entire ventral surface; locomotion- ‘pedal waves’; nervous system- simple, ladder-like; no eyes; aesthetes- organs derived from mantle tissue and extending through holes in shell plates might fn. as light receptors; linear digestive tract, mouth/anus opposite ends; algae- radula/odontophore complex, some carnivores; radular teeth capped w/iron-oxide; sugar glands release amylase-containing secretions into stomach; * Class Aplacophora- cylindrical, vermiform (worm-shaped) body w/foot forming narrow keel; in all oceans, mostly deep water; body unsegmented and bears numerous calcareous spines or scales embedded in outer cuticle; spines/scales secreted by individual cells in epidermis- no true shell; some possess style sac, small posterior mantle cavity w/ctenidia, radula (used for grasping not rasping); no conspicuous foot; no fossil record; some burrow/meander on mud, prey/live on cnidarians, interstitial; nervous system- paired cerebral ganglia, 4 linear nerve cords, ladder-like; forms calcareous spicules * Subclass Chaetodermomorpha- no foot nor ventral groove; have distinctive cuticular shield around mouth; have radula and mantle cavity housing one pair bipectinate ctenidia; marine, burrow muddy substrate; * Subphylum Conchifera- mantle tissue secretes 1 or more calcareous shells but no spicules * Class Gastropoda- (snails & slugs); visceral mass and nervous system become twisted 90-180 (torsion) during embryonic development; proteinaceous shield on foot (operculum); consists visceral mass (all internal organs) sitting atop muscular foot; visceral mass protected univalved shell usually coiled; w/shell- attached by columellar muscle from within animal's foot to central axis of shell; shell leans to left side body; shell coils clockwise (right handed/ dextral); right side organs reduced or absent; (left handed/ sinistral); elaborate behavioral/chemical defense against predators; torsion- counterclockwise 180 twisting of head/foot relative to shell, mantle, and rest of body during early development (nervous/digestive systems twisted, mantle cavity moves from rear to over the head); torsion/shell coiling independent of each other; anus discharges overhead; (detorsion can happen); movement=pedal waves; * Group Prosbranchia- mantle cavity anterior, due to torsion; most marine, small bit fresh water/land; generally free-living/mobile; most primitive; well-developed shell, mantle cavity, osphradium, radula; foot usually bears rigid disc protein called operculum; operculum may seal shell when foot retracted; ctenidium- series flattened, triangular sheets lying adjacent to each other; has heart; siphon- cylindrical extension of mantle; water enters left side and exits right side; countercurrent exchange; * Family Haliotidae- (the abalone) shallow water herbivorous snails living on solid substrates; commonly ate by people, shells for ornaments; * Superfamily Fissurellacea- (keyhole limpets) shell bears hole at top, water exits through after passing gills; marine; operculum lost at metamorphosis * Family Helicinidae- terrestrial snails living on ground or, rarely, in trees * InfraOrder Neogastropoda- most highly evolved; all marine; most carnivores; single, monopectinate otenidium, single kidney, heart w/one auricle; radula no more than 3 teeth per row; osphradium well developed and bipectinate; fertilize always internal; mantle forms in current siphon; * Order Nudibranchia- shells discarded at metamorphosis; adults lack mantle cavity and ctenidia; all marine hermaphrodites; * SuperOrder Heterobranchia- *