Lab 5 - Mollusca Flashcards
(135 cards)
1
Q
what does HAM stand for?
A
hypothetical ancestral mollusc
2
Q
Polyplacophora has (1)
A
chitons
3
Q
Bivalvia has (2)
A
clams and mussels
4
Q
Cephalopoda has (4)
A
octopus, squid, cuttlefish, and nautilus
5
Q
Gastropoda has (2)
A
snails and slugs
6
Q
Scaphopoda has (1)
A
tusk/tooth shells
7
Q
four body regions of HAM
A
head, foot, visceral mass, and mantle
8
Q
HAM: head
A
contains sensory organs and muscles
9
Q
HAM: foot
A
a muscular structure used for locomotion (usually)
10
Q
HAM: visceral mass
A
all the inners including digestive, reproductive, and circulatory organs
11
Q
HAM: mantle (3)
A
epidermal layer that covers all of the visceral mass, delimits the mantle cavity, and it also secretes a shell in species that have one
12
Q
Mollusks are an excellent example of _____ _____
A
adaptive radiation
13
Q
Mollusca: organization level
A
organ level
14
Q
Mollusca: development (3)
A
triploblastic, protostomes, eucoelomates
15
Q
Mollusca: symmetry
A
bilateral
16
Q
Mollusca: digestive
A
complete gut
17
Q
Mollusca: support
A
CaCO2 shell secreted by mantle
18
Q
Mollusca: excretion
A
via metanephridia
19
Q
Mollusca: circulation
A
open circulatory system
20
Q
what is the only class of Mollusca that has a closed circulatory system?
A
Cephalopoda
21
Q
Mollusca: locomotion
A
generally a muscular foot (not Cephalopoda)
22
Q
Mollusca: locomotion in Cephalopods
A
foot is modified into tentacles and they used jet propulsion instead
23
Q
Mollusca: sensory
A
complex sensory organs including a brain and eye in Cephalopods
24
Q
Mollusca: reporduction
monoecious or dioecious?
A
most are dioecious
25
The _____ is present in most molluscs except bivalves
radula
26
radula
rasping mouthpart used for cutting/scrapping make of a chitinous ribbon of minute teeth
27
feeding: Polyplacophora
herbivore
28
feeding: Gastropoda
mixed herbivore/carnivore
29
feeding: Scaphopoda
deposit feeder
30
feeding: Bivalvia
filter feeder
31
feeding: Cephalopoda
carnivore
32
How do land snails and slugs deal with respiration?
vascularized mantle that acts like lungs
33
Mollusca: respiration
gills mostly, except species on land
34
Class Gastropoda Subclasses (2)
- Subclass Prosobranchia
- Subclass Heterobranchia
35
Subclass Heterobranchia Infraclasses (2)
- Infraclass Euthyneura
- Infraclass Plumonata
| Class Gastropoda, Phylum Mollusca
36
Class Cephalopoda Subclasses (3)
- Subclass Ammonoidea
- Subclass Nautiloidea
- Subclass Coleoidea
37
Subclass Coleoidea Orders (2)
- Order Octopodiformes
- Order Decapodiformes
38
Defining feature of Class Gastropoda (2)
torsion - body rotates 180º
- anus is above the mouth
39
What do Heterobranchia have a secondary loss of?
torsion
40
where are members of Class Gastropoda found?
both aquatic and terrestrial
41
coiling of the shell: planispiral (2)
- coiling occurs in a single plain
- thought to be the ancestral form
42
coiling of the shell: conispiral (2)
- coiling creates a spiral in 3D
- sinistral vs. dextral
43
sinistral
left-handed coiling
44
dextral
right-handed coiling
45
what class does Subclass Prosobranchia belong to?
Class Gastropoda
46
where can members of Subclass Prosobranchia be found?
mainly marine; shelled aquatic snails
47
Subclass Prosobranchia (2)
| what is special about them?
- mantle is modified for form the siphon
- have an operculum
48
siphon
brings water to the ctenidia
49
operculum
hard covering over the aperture
50
what Class does Subclass Heterobranchia belong to?
Class Gastropoda
51
Where can members of Subclass Heterobranchia be found? (3)
marine, freshwater, and terrestrial snails and slugs
52
does Subclass Heterobranchia have a shell?
it is very reduced or absent
53
defining feature of Subclass Heterobranchia
| origin
includes gastropods with a gill origin different from that of other members
54
what Subclass does Infraclass Euthyneura belong to?
Subclass Heterobranchia
55
Where can members of Infraclass Euthyneura be found? (2)
marine and freshwater slugs
56
Do members of Infraclass Euthyneura have a shell?
very reduced or absent
57
What do members of Euthyneura have a secondary loss of?
torsion
58
What Subclass does Infraclass Pulmonata belong to?
Subclass Heterobranchia
| Class Gastropoda - Phylum Mollusca
59
where can members of Infraclass Pulmonata be found?
land snails and slugs
| Phylum Mollusca
60
what have members of Infraclass Pulmonata lost? (2)
| c.o.
- ctenidia, they have a vascularized mantle in its place
- no operculum
61
infaunal
live within the sediment rather than on top with mouths facing downward
62
what is the only Class of Mollusca to be exclusively infaunal?
Scaphopoda
63
where can members of Class Scaphopoda be found?
typically offshore rather than near beaches (marine)
64
what does Class Bivalvia lack?
a radula
65
Bivalvia: feeding (2)
most are suspension feeders but some are also deposit feeders
66
Bivalvia: respiration
they use gills
67
does Class Bivalvia have good senses?
no, except scallops that have complex eyes
68
do members of Class Cephalopoda have shells?
very reduced, except for the nautilus
69
How do members of Class Cephalopoda move?
jet propulsion
70
chromatophores
cells used for color change
71
what Class uses chromatophores?
Cephalopoda, for camouflage and warning signs
72
What Class uses ink sacks?
Cephalopoda
73
Where is ink discharged?
through the anus
74
does Class Cephalopoda have good senses?
very developed senses and nervous system
75
what are regarded as the most intelligent invertebrates?
octopods
76
hemocoel
blood-filled body cavity
77
what Class has a hemocoel?
| Mollusca
Cephalopoda
78
what Class does Subclass Ammonoidea belong to?
Cephalopoda
79
Subclass Ammonoidea (2)
- all extinct
- has distinctive sutures that marked where the septa joined the cell wall
80
what Class does Subclass Nautiloidea belong to?
Cephalopoda
81
Subclass Nautiloidea: feeding (2)
scavengers and predators of small animals in coral reefs
82
what is the only living Cephalopod with an external shell?
the Nautilus
83
Where can Subclass Nautiloidea be found?
the tropical indo-pacific
84
what Subclass does Order Decapodiformes belong to?
Subclass Coleoidea
85
Order Decapodiformes contain what animals? (2)
cuttlefish and squid
86
how is the shell reduced in cuttlefish?
the cuttlebone
87
how is the shell reduced in squid?
the pen
88
how many arms do members of Order Decapodiformes have?
eight arms with two additional tentacles
89
what Subclass does Order Octopodiformes belong to?
Subclass Coleoidea
90
where are members of Order Octopodiformes found?
all marine habitats, associated with the ocean floor
91
do members of Order Octopodiformes have shells?
no
92
Polyplacophora appear segmented because of the eight -valves- (shells). However, internally, they show no signs of segmentation, and it is not known in other Mollusca. What is the most likely explanation for this?
The eight shell 'segmentation' evolved independently in Polyplacophora
93
What feature is shared by Gastropoda and Polyplacophora?
a large muscular foot
94
What factor is responsible for the similarity of the large muscular foot shared by Gastropoda and Polyplacophora?
method of locomotion
95
The term 'slug' is used to refer to Gastropods that have lost their shell. Evolutionary loss of a shall has occurred more than once. Which feature would you expect to be shared by different groups of slugs?
A secondary loss of torsion and reduction/complete loss of a shell
96
the umbo represents what side of the shell?
dorsal, so the other end is ventral
97
the umbo points in a direction slightly, this direction is?
anterior, so the opposite is posterior
98
where can the hinge ligament be found?
| Bivalvia
the dorsal side
99
What feature does Scaphopoda and Bivalvia share?
a reduced or absent head
100
What explains why Scaphopoda and Bivalvia have a reduced/absent head?
their method of feeding
101
A bivalve way of feeding if ecologically most similar to what other organism?
sponge
102
Why do you suppose the adductor muscles are so well developed un Bivalvia? (2)
to allow bivalves to keep their shells closed as a defense mechanism (scallops) and to help with better filter feeding
103
name the three functions of the gills in Bivalves
1. reproduction
2. filter feeding
3. respiration
104
How are the gills of squid and the gills of clams different from one another?
The gills of squid functions only in respiration, while in clams they are for respiration, feeding, and reproduction
105
WHy are sensory structures more prevalent on Cephalopoda than on Bivalvia?
Because Cephalopods are highly active predators, they have benefited from advances in their sensory organs, particularly vision. Sessile Bivalves do not need these adaptations.
106
what are the four body region characteristic of molluscs?
1. head
2. foot
3. visceral mass
4. mantle
107
Which Subclass/Order(s) has gas-filled chambers?
Subclasses Ammonoidea and Nautiloidea
108
Which Subclass/Order(s) has a reduced shell to an internal 'bone'?
Order Decapodiformes
109
Which Subclass/Order(s) has a reduced shell as a 'pen'?
Order Decapodiformes
110
Which Subclass/Order(s) has an absent shell?
Order Octopodiformes
111
Scaphopodoa
112
Identify the class of the specimen.
Class Polyplacophora
| Mollusca
113
What is the function of the structure indicated by line D?
Locomotion
114
Identify the class of the specimen.
Bivalvia
115
What is the function of the structure indicated by line A?
the mantle produces the shell
116
Identify the structure indicated by line B.
gills
117
What is structure C?
gills
118
What is structure A?
branchial heart
119
What structure is B?
cecum
120
What is the function of the structure indicated by line E?
reproduction
121
Is this specimen male or female?
female
| nidamental glands
122
What structure above indicates the specimen's sex?
nidamental glands (female)
123
What are some features that contribute to squid as a successful predator? (6)
1. well developed eyes
2. extensible tentacles with suckers
3. siphons for jet propulsion
4. fins for maneuvering
5. closed circulatory system for gas exchange
6. aerodynamic body
124
The great diversity of molluscs is an example of what evolutionary phenomenon?
adaptive radiation
125
The cephalopod eye and the vertebrate eye demonstrate what evolutionary phenomenon?
convergent evolution
126
what is this specimen?
a Nautilus shell
127
what is this specimen?
a Cuttlefish bone
Class Cephalopoda
128
A; umbo
129
what are these specimen?
Class Bivalvia
130
what specimen made these holes, what Class do they belong to?
Shipworms, Class Bivalvia
131
what are these specimen?
tusk/tooth shells of Class Scaphopoda
132
what Class/Subclass/Infraclass do these specimen belgong to?
Class Gastropoda, Subclass Heterobranchia, Infraclass Euthyneura
133
what Class/Subclass/Infraclass does this specimen belong to?
Class Gastropoda, Subclass Heterobranchia, Infraclass Euthyneura
134
what Class/Subclass/Infraclass does this specimen belong to?
Class Gastropoda, Subclass Heterobranchia, Infraclass Euthyneura
135
