Terms in this set (40)
What are the defining charactersitics of Lophotrochozoans
some have feeding device called lophophore, some have trocophore larva, some have spiral cleavage, bilaterian; protostomes
What are the characteristics of the lophophore?
- U-shaped ring of tentacles
- Covered with cilia
- Used in capturing small food particles and in respiration
- Found in the phyla Brachiopoda, Bryozoa, Entoprocta, and Phoronida
What are the characteristics of trocophore larva?
Has a band of cilia around the body. Found in the phyla Annelida, Mollusca and others
Why were Lophophorates originally considered to be closely related to Deuterostomes?
Why are lophophorates now considered to be members of the Protostomes?
What do all Lophotrochozoans have in common?
feeding structure called lophophore; trocophore larvae
What phyla belong to the lophotrochozoans?
Bryozoans, Entoprocts, Platyhelminthes, Pogonophorans, Brachiopods, Phoronids, Nemerteans, Annelids, Echiurans, MOLLUSCS, Sipunculans, Gnathostomulids, Rotifers
What animals are part of Mollusca?
snails, clams, octopuses
Where does the name Mollusca come from?
Latin mollis/molluscus = soft
What are the defining characteristics of Mollusca?
body covered by a mantle that secretes shell; ribbon of small teeth called radula that is used to feed; ventral muscular foot used in locomotion; head with eyes & other sensory organs
What are the 5 major classes of Molluscs?
Gastropoda, Bivalvia, Scaphopoda, Polyplacophora, Cephalopoda
Describe the molluscan digestive system?
separate mouth and anus; involves salivary and digestive glands that release digestive enzymes
Mollusc grazers have what characteristics?
Gastropods and Polyplacophorans. rasping radula used to remove alge from surfaces or slice seaweed
Mollusc herbivores have what characteristic?
relatively long guts
What is special about Elysia chlorotica?
they're a grazer that steals chloroplasts and genes from the algae they eat. they can use them to photosynthesize
What is special about Aeolidia papillosa aka: nudibranchs?
they feed on cnidarians and steal their nematocysts. they use the undischarged nematocysts as a defense
How do bivalves feed?
they ingest food particles that are filtered and sorted by cilia on the gills; food transported to mouth by cilia and mucus; food digested in stomach with crystalline style
How do cephalopods feed?
all are carnivores that digest large prey
Describe the molluscan circulatory system
dorsal muscular heart pumps blood to all tissues, most have open circulatory system (blood flows into open spaces)
Describe the circulatory system of cephalopods
closed circulatory system in which blood remains in vessels, blood more effectively directed to brain and muscles
How do molluscs reproduce?
most have separate sexes but most are hermaphrodites. In bivalves/tusk shells/some gastropods have external fertilization. Gametes released into water column where fertilization occurs
How do cephalopods and most gastropods reproduce?
internally. cephalopod males use modified arm to transfer spermatophore to female.
How do hermaphrodite molluscs reproduce?
can be sequential or simultaneous hermaphrodites. mating of simultaneous can involve a battle including stabbing and hormonal manipulation
What is the largest/most common/most varied group of molluscs?
What are some names of gastropods?
snails, nudibranchs, limpets and abalones
What are the characteristics of gastropods?
coiled mass of vital organs, enclosed by dorsal shell, moves around on ventral creeping foot
What are some of the characteristics of cone snails?
500+ species, killing machines, find their prey using olfactory cues from water drawn in through siphon, can also bury beneath sand and be sit and wait predators, found in the tropics and subtropics with coral reefs
How do cone snails capture prey?
They use highly modified radular tooth to puncture prey and deliver venom; venom is cocktail of short chain amino acid toxins that attack ion channels; individual species can produces hundreds of different conotoxins (by different genes that arose from duplication events); then they ingest prey whole
How did cone snails evolve?
rate of evolution of conotoxin genes is very high
What is a likely cause of rapid evolution of cone snails?
Co-evolution of predator and prey. Prey that evolve resistance to conotoxins are favored by selection. Predators that evolve new conotoxins to capture and immobilize prey are favored by selection
Who is someone who studied cone snails?
What species are included in the class bivalvia?
clams, mussels, oysters
What are the characteristics of bivalvia?
body is laterally compressed, enclosed in a shall with two parts (VALVES); no head and no radula (secondary losses); gills used to obtain oxygen and filter water for food; strong adductor muscles are used to close the valves
What species are part of the class Cephalopoda?
octopuses, squids, cuttlefish and nautiloids
What are the defining characteristics of cephalopods?
active way of life; foot modified into arms and tentackes with suckers to capture prey; complex nervous systems; well-developed sense organs
What are the defining characteristics of the cephalopod brain?
300-500 mil neurons like cat; complex social behavior, ability to learn and problem solve
What are the characteristics of cephalopod eyes?
convergently evolved to vertebrate eyes; focus by moving lens instead of changing its shape; no nerve fibers between lens and photoreceptors so no blindspot
What are the defining characteristics of polyplacophorans?
"chitons"; 800 species; 8 overlapping shell plates; shallow hard-bottom environments
What are the defining characteristics of monoplacophorans?
thought to just be fossils until 1952; few extant limpet-like species; deep water environments
What are the defining characteristics of scaphopods?
tusk shells; 350 species; elongated shell open at top and tapered like elephant tusk; most found in sandy or muddy bottom environments
YOU MIGHT ALSO LIKE...
RNR 4145 Freshwater Lab Exam
Marine Biology: Chapter 9
Marine Biology Chapter 10
Chapter 31: Sponges, Cnidarians, Ctenophores, and Protostomes
OTHER SETS BY THIS CREATOR
License Suspension Periods for Refusing a Chemical Test
License Suspension Periods for Failed Chemical Tests
Penalties for Operating a Motor Vehicle Under the Influence
Criminal Offenses and Suspensions
THIS SET IS OFTEN IN FOLDERS WITH...