Lecture Exam 3 Flashcards
common names of Phylum Mollusca
snails and slugs, oysters and clams, octopuses and squids, etc
where do molluscs live
mostly marine, some freshwater, and some snails and slugs are terrestrial
main characteristic of molluscs
soft-bodied, and most are protected by a calcium carbonate shell
feeding characteristics of molluscs
herbivorous grazers, predaceous carnivores, filter feeders, or parasites
first characteristic of molluscs
all have a similar body plan with three main parts
three main parts of molluscs’ body plan
muscular foot/head, visceral mass, mantle
what is the head/foot region in molluscs
contains feeding and cephalic sensory organs, and large ventral muscular foot
what is the visceral mass in molluscs
contains digestive, circulatory, respiratory, and reproductive organs
what is the function of the mantle in molluscs
secretes the shell over the visceral mass
what is the mantle cavity in molluscs
the space between mantle and body wall
second characteristic of molluscs
bilateral symmetry, unsegmented
third characteristic of molluscs
triploblastic
fourth characteristic of molluscs
coelomate (coelom limited to area around heart)
fifth characteristic of molluscs
open circulatory system
open circulatory system
pumping heart, blood vessels, and blood sinuses (spaces in body)
-most cephalopods have a closed system with a heart, vessels, and capillaries
sixth characteristic of molluscs
pair of kidneys or metanephridia
seventh characteristic of molluscs
nervous system: pairs of ganglia with connecting nerve cords
eighth characteristic of molluscs
sense organs vary and may be highly specialized
-cephalopods have highly developed eyes
mollusc feeding
feed using a radula
radula
-protruding, rasping, tongue-like organ
-ribbon-like membrane has rows of tiny teeth pointed backwards
do molluscs reproduce asexually
no
are molluscs dioecious or monoecious
most are dioecious, some monoecious
mollusc development
egg hatches and produces a free-swimming trochophore larva
-in many gastropods and bivalves there is a veliger larva
veliger larva
intermediate larval stage which has the beginning of a foot, mantle, and shell
classes of molluscs
Polyplacophora, Gastropoda, Bivalvia, Cephalopoda
common name of Polyplacophora
chiton
main characteristic of chitons
oval-shaped marine animals encased in an armor of 7-8 dorsal plates
how do chitons use their foot
they use it like a suction cup to grip rocks, and they use their radula to scrape algae off the rock surface
where are the gills in chitons
suspended from roof of mantle cavity and grooves form a closed chamber
how is blood pumped in a chiton
it is pumped by a three-chambered heart
reproduction of chitons
sexes are seperate
-sperm and egg are released into the water
-trochophore larvae metamorphize into juveniles, without a second larval stage
class Gastropoda common names
snails, limpets, slugs, whelks, conches, periwinkles, sea slugs, sea hares, sea butterflies, and nudibranches
where do gastropods live
marine, freshwater, or terrestrial
typical movement of gastropods
sluggish, sedentary animals
what do gastropods use as defense
their shells
main characteristic of gastropod shells
one-piece (univalve), coiled or uncoiled, often with 180 degree counterclockwise torsion
operculum in gastropods
covers shell aperture, protects and prevents water loss
torsion
-causes the digestive tract to move laterally and dorsally so that the anus lies above the head within the mantle cavity
respiration in gastropods
performed by gills in mantle cavity, or by a highly vascular area of mantle that functions as a lung
pneumostome
small opening in air-breathing gastropods that leads from the lung to outside
class Bivalvia common name
mussels, clams, scallops, oysters, and ship wormss
shell characteristics of bivalves
a shell divided into two halves
mantle cavity of bivalves
contains gills that are used for feeding as well as gas exchange
what structures do bivalves lack?
a head, radula, and cephalization
where do bivalves live
mostly marine
bivalve movement
mostly sedentary, but some have some limited mobility
form and function of bivalves
-two shells or valves are held together by a hinge ligament and held together by strong adductor muscles, and the valves are open when adductor muscles are relaxed
feeding and digestion of bivalves
most are suspension feedings
bivalve hearts
three chambered heart
class Cephalopoda common names
squids, octopuses, nautiluses, and cuttlefish
where do cephalopods live
marine
how big do cephalopods get
2 cm to the giant squid
what did the foot adapt into in cephalopods
arms, tentacles, and funnel (siphon)
how many arms and/or tentacles do nautiluses have
60-90 tentacles, no suckers
how many arms and/or tentacles do octopuses have
8 arms with suckers
how many arms and/or tentacles do squids and cuttlefish have
8 arms with suckers and 2 tentacles
which cephalopods produce venom
octopuses and cuttlefish (produced in salivary glands)
how do cephalopods grasp prey
strong beaklike jaws
nautilus shell
has multiple chambers, allowing them to swim
cuttlefish shell
enclosed within mantle
squid shell
thin strip called the pen, enclosed in mantle
octopus shell
N/A
chromatophores
pigmented skin cells in squids and octopuses
inc sac purpose in cephalopods
defense
respiration in cephalopods
one pair of gills
cephalopod circulation
muscular pumping system to keep water flowing through the mantle cavity
characteristics of cephalopod circulatory system
-complete circulatory system
-accessory or branchial hearts at the base of each gill increases pressure to blood going through cill capillaries
cephalopod reproduction
-dioecious
-direct development
-in male seminal vesicle, spermatozoa are encased in spermatophores and stored
-removes a spermatophore from mantle cavity and inserts it into female
-fertilized eggs leave oviduct and are attached to stones, etc
-some octopuses tend to their eggs
main characteristic of phylum Annelida
segmented worms
common names of annelids
marine bristle worms, fan worms, leeches, and earthworms
where do annelids live
marine, freshwater, and moist terrestrial habitats
first characteristic of annelids
segmentation or metamerism
-bodies composed of serially repeated units or rings
-each unit contains components of most organ systems (circulatory, nervous, and excretory systems)
advantages of metamerism
-greater complexity in structure and function
-increased burrowing efficiency by permitting independent movement of segments
-evolution of a more sophisticated nervous system
-provided a safety factor
second characteristic of annelids
bilateral symmetry
third characteristic of annelids
triploblastic
fourth characteristic of annelids
paired epidermal setae
paired epidermal setae
-tiny chitinous bristles
-absent in leeches
-mostly used for locomation
fifth characteristic of annelids
unique head and terminal end
annelid head segments
prostomium and peristomium
pygidium
terminal segment bearing the anus in annelids
-new metameres form in front of the pygidium
are head and pygidium true segments
no, because they are not serially repeated
sixth characteristic of annelids
coelomate
-coeloms form by schizocoely
-segments separated by septa
seventh characteristic of annelids
hydrostatic skeleton (except in leeches)
-contraction of circular muscles causes body to narrow and lengthen
-contraction of longitudinal muscles causes body to shorten and expand
eighth characteristic of annelids
digestive system complete, not segmented
ninth characteristic of annelids
nervous system is composed of a double ventral nerve cord
what does the double ventral nerve cord look like in annelids
they are ladder-like so it looks like one cord
tenth characteristic of annelids
asexual reproduction by fission and fragmentation
eleventh characteristic of annelids
sexual reproduction (hermaphroditic or dioecious, no self fertilization)
twelfth characteristic of annelids
share a trochophore larva with the ancestor
thirteenth characteristic of annelids
respiration through skin, gills, or parapodia
fourtheenth characteristic of annelids
circulatory system closed and segmented
fifteenth characteristic of annelids
excretory system segmented
three traditional classes for annelids
class Polychaeta, class Oligochaeta, class Hirudinida
common name of class Polychaeta
aquatic worms
common name of class Oligochaeta
earthworms
common name of class Hirudinida
leeches
polychaetes’ life habits
sedentary ones are mostly tube-living, active ones may be free-moving, burrowing, or crawling
how big do polychaetes get
up to 4 feet long
characteristics of polychaetes
-parapodia
-setae
-eyes, tentacles, and sensory palps
parapodia
paired appendages on most segments of polychaetes
-have two main parts: dorsal notopodium and ventral neuropodium
setae in polychaetes
arranged in bundles on parapodia
are prostomium retractile in polychaetes?
may or may not be
characteristics of mouth in polychaetes
surround mouth
reproduction and development of polychaetes
-no permanent sex organs (every mating season, they grow new ones)
-seperate sexes
-fertilization is external and the early larva is a trochophore
class Oligochaeta common name
earthworms
earthworm habitats
soil to freshwater
how do earthworms live
burrow in moist rich soil and usually live in branched interconnected tunnels
clitellum
thickened glandular and nonsegmented section of the body wall of earthworms used for reproduction
earthworm setae
four pairs on each segment
-bristle-like rods set in a sac and moved by tiny muscles
-project outward through small pores in cuticle
-aid anchoring by digging into walls of burrow
earthworm nutrition
scavengers
excretory structures in earthworms
-nephridia
-nephrostome
-bladder
-nephridiopore
nephridia
kidney-like structures found in each body segment of an earthworm, except the first three and terminal segments
nephrostome
a ciliated funnel in earthworms that draws in wastes and leads through the septum
bladder
where the nephrostome ends and empties outside at the nephridiopore
nephridiopore
the exit place for waste in an earthworm
oligochaetes’ nervous system and sense organs
pair of dorsal cerebral ganglia connect around the pharynx to the ganglia of the ventral nerve cord to form the brain
earthworm reproduction characteristics
-hermaphroditic
-cross-fertilization
detailed earthworm reproduction process
-aligning in opposite directions, ventral surfaces together
-mucus secreted by clitellum holds worms together
-sperm from each worm are transported to the seminal receptacles of the other worm along seminal grooves
-after mutual copulation, each worm secretes a mucus tube and chitinous band to form a cocoon
-cocoon passes forward and eggs, albumin, and sperm are poured into it
-fertilization occurs in cocoon, cocoon slides off head end and closes
-young worms emerge from cocoon
class Hirudinida common name
leeches
leech characteristics
34 segments, possess anterior and posterior suckers, no septa
what is the function of the posterior sucker on leeches
to attach to the host animal
what is the function of the anterior sucker on leeches
to suck blood
where do leeches live
mostly freshwater, few marine, some live in moist terrestrial environments
color of leeches
black, brown, red, and olive green
do leeches have setae
no
exception to the rules about leeches
Acanthobdellidae: 27 segments, setae only present on the first five segments, and have a posterior sucker
leech nutrition
-mostly parasitic that suck blood, but not all are parasitic
-some predaceous on small invertebrates
-some parasitic leeches slit the skin of the host and secrete an anesthetic to prevent detection
-secrete a chemical called hirudin to prevent blood from coagulating
leech reproduction
-hermaphroditic and practice cross-fertilization
-sperm transferred by a penis or hypodermic impregnation
-clitellum (only evident during breeding season) secretes cocoon to receive sperm and egg
-cocoons are buried in mud or damp soil
-development is similar to that of oligochaetes
what is the most abundant group of animals on earth
arthropods
how big are arthropods
0.1 mm to 3.7 m
arthropod common names
spiders, mites, ticks, scorpions, crustaceans, millipedes, centipedes, insects, etc
main characteristics of arthropods
-versitile hard exoskeleton
-segmentation and appendages for more efficient locomotion
-air distribution directly to cells
-highly developed sensory organs
-complex behavior patterns
-metamorphosis
how far back does the fossil record for arthropods go
back to mid-Cambrian period
first characteristic of arthropods
joined appendages (modified for specialized functions)
second characteristic of arthropods
bilateral symmetry
third characteristic of arthropods
segmented body divided into functional units called tagmata (head, thorax, abdomen)
fourth characteristic of arthropods
triploblastic
fifth characteristic of arthropods
small coelom filled with blood
sixth characteristic of arthropods
jointed exoskeleton made of chitin that must be shed (molt) for growth (also called Ecdysis)
seventh characteristic of arthropods
complete digestive system
eighth characteristic of arthropods
complex muscular system
ninth characteristic of arthropods
nervous system is composed of a dorsal brain and ventral nerve cord
tenth characteristic of arthropods
asexual reproduction by fission and fragmentation
eleventh characteristic of arthropods
well developed sense organs
twelfth characteristic of arthropods
respiration by body surface, gills, trachea, air tubes, or book lungs
thirteenth characteristic of arthropods
open circulatory system (blood fills coelom)
fourtheenth characteristic of arthropods
paired excretory glands (ie. maxillary glands)
-not kidneys!
fifteenth characteristic of arthropods
sexual reproduction, dioecious, internal fertilization
sixteenth characteristic of arthropods
most have metamorphosis
seventeenth characteristic of arthropods
social organization
subphylum groups of arthropods
-Trilobita
-Chelicerata
-Myriapoda
-Crustacea
-Hexapoda
main characteristic of Trilobita
extinct
main characteristic of Chelicerata
fangs
main characteristic of Myriapoda
many legs
main characteristic of Crustacea
crabs, shrimp, etc
main characteristic of Hexapoda
six legs
common names of Chelicerata
horshoe crabs, spiders, ticks, mites, scorpions, sea spiders
segments of Chelicerata
two tagma (cephalothorax and abdomen)
how many appendages do Chelicerata have
six pair of cephalothoracic appendages
-one pair of chelicerae
-one pair of pedipalps
-four pairs of walking legs
chelicerae
claw-like feeding appendages that suck liquid food from prey
pedipalps
modified legs on arthropods that hold prey
do Chelicerata have mandibles or antenna
no
classes of Chelicerata
Meristomata, sea spiders, and Arachida
common name of class Meristomata
horseshoe crabs
Arachida common name
spiders, scorpions, ticks, and mites
Meristomata characteristics
carapace, abdomen with book gills, telson, blue blood
sea spiders characteristics
four pairs of walking legs, large sucking proboscis, small abdomen
Arachida characteristics
-chelicerae function as fangs
-cephalothorax and abdomen joined by thin pedicel
-four paired legs
-gas exchange through book lungs
-excretion through Malpighian tubules
-many spiders produce silk, a liquid protein, from specialized abdominal silk glands
Arachida common names
spiders, scorpions, whip scorpions, pseudoscorpions
chelicerae function in Arachida
function as fangs
pedicel
joins cephalothorax and abdomen in Arachida
how many legs do Arachida have
4 pairs
how does gas exchange occur in Arachida
through book lungs
Malpighian tubule purpose
excretion
what is silk
a liquid protein produced by Arachida from specialized abdominal silk glands
main characteristics of phylum Myrapoda
-2 tagmata
-1 pair of antennae
-mandible and two pairs of maxillae
-legs are uniramous
how many tagmata do myrapodes have
two
how many pairs of antennae do myrapodes have
one
what feeding structures do myrapodes have
mandible and two maxillae
are myrapode legs uniramous or biramous
uniramous
what are the tagmata of myrapodes
head and trunk
-paired appendages on trunk segments
uniramous definition
one branch
classes of subphylum Myrapoda
Class Chilopoda and Class Diplopoda
common name of chilopodes
centipedes
common name of diplopodes
millipedes
characteristics of centipedes
-predators
-each segment contains one pair of legs
-dorsoventrally flattened
-maxillipeds on first segment are modified to venom claws
-pair of eyes of group of ocelli
maxilliped definition
first jaw
millipede characteristics
-cylindrical bodies
-4 thoracic segments, one pair of legs
-herbivorous
-slow, curl up in a ball for protection
characteristics of crustaceans
-2 pairs of antenna
–head has a pair of mandibles and 2 pairs of maxillae
-one pair of appendages on each of the additional segments
-all appendages are biramous
-collect oxygen by moving their legs
-tagma are usually head, thorax, and abdomen
-one or more thoracic segments are fused with the head as acephalothorax
-dorsal covering is carapace
-compound eyes
how many antennae do crustaceans have
two pairs
are crustaceans biramous or uniramous
biramous
how do crustaceans collect oxygen
by moving their legs
crustacean tagma
head, thorax, abdomen
what structure covers crustaceans
carapace
what structure covers crustaceans
carapace
characteristics of crustaceans eyes
compound eyes
compound eyes
made of many units called ommatridia
reproduction of crustaceans
-dioecious
-brood eggs in brood chambers, in egg sacs attached to the abdomen, or attached to abdominal appendages
crustacean life cycles
-most have a larva unlike the adult in form
-undergo metamorphosis
-nauplius larva is the common larval form
nauplius larva
unsegmented body, frontal eye, 3 pairs of appendages
characteristics of subphylum hexapoda
-3 tagmata (head, thorax, abdomen)
-3 pairs of uniramous legs
characteristics of Hexapoda
-large groups
-wide variety of habitats but few are marine
-bases of mouth parts visible
-winged or wingless
-comppound eyes
-thorax
-2 pairs of wings may be present, modified, or absent
pterygotes
winged hexapodes
apterygotes
wingless hexapodes
hexapode thorax
-prothorax, mesothorax, metathorax
-legs on each segment
-wings on mesothorax and metathorax
