EVSC 4320 Midterm 2

“Peanut worms”Found buried in rock/sedimentsSoft body, sometimes have a shellIntrovert connects the tenticles to the trunk, and is retractableU-shaped disgestive system, anus near mouth, close to edge of benthos
Small wormTentacles at one end, anchor to tube at otherNo digestive systemFound in deep vent communities, can be large and red (hemoglobin) Absorbs nutrients, or symbiosis with bacteria
Beige colored, somewhat rare, several inches longProboscis is unretractable, like a rolled tongueLays proboscis out, and scilia brings in organic material that comes into contact
Smallest of metazoa, looks like tiny scaled bearsHerbivorous, right stylets puncture cell walls, mouthp placed near, pharynx sucks out cytoplasm.

Can form cysts

Phylums that share a lophophore, food gathering structure.Includes Phoronida, Byrozoa, Brachiopoda, Entoprocta
Lophophore looks like a coiled horseshoe with tentaclesMouth in middle, U digestionsmall, lives in sediments
Very common in coastal environmentsLive in colonies, can attach to piers, etcLooks almost like plantsTentacles pull down food, passes food down and shares with others in colonySome individuals are assigned to reproduction, feeding, etcLater step of “fowling communities”, after bacteria and barnacle buildup
Two values, different from molluscs, b/c valves are different, dorsal
Benthic, have an attachment discU shaped digestion
“Arrow worms” planktonBenthic members are more robust, move in interstitial spacesCan be pelagic, transparentStructured as a long tube, two sets of lateral finsAggregation of nervous ganglier material near ventral surfaceHead region contains grasping spines teeth, sensory pitsLittle hairs all over body, every species has different placementUsed to sense pressure waves, different species sense different frequencies, go after different prey
Echinodermata, Stelleroida
Phylum, classDerived radial symmtetryExclusively marineInternal skeleton composed of calcium carbonate platesWater vascular system, like internal hydraulicsNone are parasitic, found in all marine environments
Enchinodermata, Asteroida
Subclass, sea starsCentral disc, 5 soft arms (connected), oral surface faces downOsicles (internal skeleton) embedded in outer tissueTube feet connected to canal system, suction powered by “hydraulics”, attaches to shells, rocks, etcTwo stomachs, one can be exuded out of mouth, begin digesting things like bivalvesRegenerative, can survive as long as severed arm contains part of central disc
Echinodermata, Ophiuruidea
(sub class) “Brittle stars”Lots of space between arms on central discStomach does not exit, uses teeth to devour food brought in with armsOssicles are now in the middle of arms, (wooden snake ex)Uses arms to wave around, crawlHas tube feet, more round and not used for feeding
Echinodermata, Echinoidea
(class), urchins, etcOssicles are like skull plates, fused together into a sphereSpines and podia protrudeOral and aboral surfaces
Diadema, spp
Black spiny sea urchin (Echinoidea class)Mucusy epidermis covers layer over all of spines, can be left in your skinJaws on oral surface, 5 arrow shaped teeth that extend upwards – “Aristotle’s Lantern”
Sand Dollars
Part of Echinodermata, EchinoideaCompressed urchinsPodia etc, uses them to bury self in sediment through holes in skeleton
Echinodermata, Holothuroidea
Sea cucumbersLive on benthos, or in sedimentsSurface on bottom has highest concentration of tubefeet/podia, called soleCrown of tentacles at one endOssicles are nearly absent, Wave tentacles in sediment or water column, food sticks to it, wipes it off and consumes in mucus gland
Echindoermata, Crinoidea
(class) most primitive, used to dominateWell defined ossicles, Feathery area attached to main bodySuspension feeders
Chardata, Urchardata, Ascidiacea
(class) sea squirtsCan be relatively transparentIn-current pore, ex-current pore, sued for filter feeding”Turicates”Basket inside filters out water, endostyle secretes mucus, which spreads out around basket, transports everything into digestive systemLarval form , almost like a tadpole, pelagicFind a place on benthos to attach, metamorphose into a benthic adult
Chordata, Urchardata, Thaliacea
(class) salpsEntirely pelagic, found in open oceanBarrel-like form, water flows through cylinderContains endostyle that creates mucus web, funnels particles into mouth, constantly consumingAttach together to form salp chainsSo good at capturing small particles, most live in clearer non coastal waterAlternation of generation, stick together with asexually reproduced organisms to form chainsOther organisms live on salp chains (fish, etc)
Chordata, Urchardata, Larvacea
(class)Secretes gelatinous housePelagic, open ocean, filteringTwo channels for water to move throughMoves tail in house to move currentFilters out large particles, smaller particles are led to smaller filer so it can eatWhen large filter (grid) is clogged, animal flicks its tail and loses its house, secretes new one