Lecture 4: Osteichthyes (bony fish)

Question 1

What are the two key features that define vertebrates’ transition from Urochordates to craniates?

A) Tentacles and exoskeleton
B) Vertebral column and protective skull
C) Gills and fins
D) Shell and mandibles

Answer 1

B) Vertebral column and protective skull

Question 2

Which infraphylum belongs to the subphylum Craniata?

A) Agnatha
B) Arachnida
C) Chelicerata
D) Myriapoda

Answer 2

A) Agnatha

Question 3

Which of the following is a characteristic feature of Agnatha?
A) Presence of jaws
B) Cartilaginous skeleton
C) Paired fins
D) Lack of paired fins
E) Gills between external and internal branchial arches

Answer 3

E) Gills between external and internal branchial arches

Question 4

What is the primary distinguishing feature of Agnatha?
A) Presence of scales
B) Lack of vertebrae
C) Presence of jaws
D) Lack of paired appendages

Answer 4

d) Lack of paired appendages

Question 5

4. Hagfish and lampreys are examples of which group of vertebrates?
   A) Osteichthyes
   B) Chondrichthyes
   C) Myxini
   D) Reptilia

Answer 5

c) Myxini

Question 6

5. What is the feeding mechanism of Agnatha?
   A) Filter feeding
   B) Suction feeding
   C) Biting and chewing
   D) Herbivory

Answer 6

b) suction feeding

Question 7

What is the defining characteristic of Gnathostomata fish?
A) Presence of jaws
B) Lack of paired fins
C) Cartilaginous skeleton
D) Filter-feeding mechanism

Answer 7

a) presence of jaws

Question 8

Which subclass of Gnathostomata fish is known for having a bony skeleton?
A) Chondrichthyes
B) Osteichthyes
C) Myxini
D) Amphibia

Answer 8

b) Osteichthyes

Question 9

During which geological era and period did Chondrichthyes first emerge?

A) Mesozoic Era, Jurassic Period
B) Paleozoic Era, Ordivician-Silurinan Period
C) Cenozoic Era, Miocene Period
D) Precambrian Era, Cambrian Period

Answer 9

B) Paleozoic era, ordivician-silurian periods

Question 10

How did jaws likely form in Chondrichthyes?

A) Through the fusion of the skull bones over time.
B) By the direct transformation of fins into jaws.
C) Via modifications to the skeletal structure of the first pair of gill arches.
D) Through the sudden appearance of fully formed jaws.

Answer 10

C) Via modifications to the skeletal structure of the first pair of gill arches.

Question 11

What changes occurred during the transition from Agnathans to Gnathostomes?

A) Development of a bony exoskeleton.
B) Loss of paired fins and acquisition of jaws.
C) Transition from internal to external fertilization.
D) Increase in body size and decrease in reproductive rate.

Answer 11

B) Loss of paired fins and acquisition of jaws.
- with the loss of paired fins, jawed fish eventually gained pectoral and pelvic fins

Question 12

What distinguishes the Agnathan jaw from the Gnathostome jaw?

A) The Agnathan jaw features a ventilatory mechanism, while in Gnathostomes, the first mandibular arch is enlarged, facilitating a stronger suction for prey.
B) The Agnathan jaw lacks teeth, whereas the Gnathostome jaw possesses numerous sharp teeth for prey capture.
C) The Agnathan jaw is made of cartilage, whereas the Gnathostome jaw is composed of bone.
D) The Agnathan jaw is fixed and immobile, contrasting with the flexible and hinged nature of the Gnathostome jaw.

Answer 12

A) The Agnathan jaw features a ventilatory mechanism, while in Gnathostomes, the first mandibular arch is enlarged, facilitating a stronger suction for prey.

Question 13

Which evolutionary sequence describes the transition from jawless fish (Agnathans) to jawed fish?

A) Development of external brachial arches -> Formation of ventilator jaws -> Emergence of mandibular arches
B) Evolution of muscularized gill openings -> Formation of internal and external branchial arches -> Development of upper lip
C) Strengthening of gill openings -> Evolution of internal branchial arches -> Emergence of upper lip
D) Emergence of mandibular arches -> Formation of muscularized first gill arch -> Development of external brachial arches

Answer 13

A) Development of external brachial arches -> Formation of ventilator jaws -> Emergence of mandibular arches

Question 14

Which group of fish are considered early Gnathostomes, playing a crucial role in the evolution of vertebrates in regard to the notochord?

A) Placoderms
B) Agnathans
C) Actinopterygii
D) Myxini

Answer 14

A) Placoderms

Question 15

What are some of the anatomical changes that occurred within jawed fish, allowing for a more active lifestyle?

A) Development of a bony exoskeleton and reduction in fin size
B) Addition of paired fins, more prominent dorsal fin, and repositioning of pectoral and pelvic fins
C) Loss of gill openings and elongation of the body
D) Increase in body size and enlargement of the upper lip

Answer 15

B) Addition of paired fins, more prominent dorsal fin, and repositioning of pectoral and pelvic fins

Question 16

Which evolutionary development contributed significantly to the enhanced mobility and maneuverability of early vertebrates in aquatic environments?

A) Formation of the notochord
B) Development of a bony exoskeleton
C) Emergence of paired fins
D) Evolution of lungs for aerial respiration

Answer 16

C) Emergence of paired fins

Question 17

What is the main premise of the Fin Fold Theory?
A) It suggests that paired fins originated as extensions of the dorsal and ventral fins.
B) It argues that paired fins evolved independently in different lineages of vertebrates.
C) It proposes that paired fins evolved from specialized folds of skin along the body.
D) It posits that paired fins evolved from modifications of the skeletal elements associated with the gill arches.

Answer 17

c) proposes that paired fins evolved from specialized folds of skin along the body

Question 18

What is the central idea behind the Gill Arch Theory?

A) It proposes that paired fins evolved from modifications of the skeletal elements associated with the gill arches.
B) It suggests that paired fins originated as extensions of the dorsal and ventral fins.
C) It argues that paired fins developed from specialized folds of skin along the body.
D) It proposes that paired fins evolved independently in different lineages of vertebrates.

Answer 18

A) it proposes that paired fins evolved from the modifications of the skeletal elements associated with the gill arches

• however there is not much support for this theory as it does not explain the paired fins in the pelvic region becasue gills are at the front

Question 19

What anatomical feature distinguishes placoderms from cephalochordates?

A) Prominent notochord
B) Presence of dorsal and ventral arches
C) Extensions above and below the body
D) Lack of a notochord

Answer 19

B) Presence of dorsal and ventral arches

Question 20

Which clade includes the Acanthodians, osteichthyes, and tetrapods among the Gnathostomes?

A) Chondrichthyes
B) Teleostomi
C) Osteichthyes
D) Tetrapodomorpha

Answer 20

B) Teleostomi

Question 21

What is considered the earliest fossil evidence of jawed vertebrates?

A) Placoderms
B) Acanthodii
C) Agnatha
D) Chondrichthyes

Answer 21

B) Acanthodii

Question 22

Which of the following characteristics is unique to Acanthodii among early vertebrates such as the Chondricthyes?

A) Presence of placoid scales
B) Fully ossified internal skeleton
C) Lack of spines on their body
D) Streamlined body shape and ganoid scales
E) Partially ossifed skeleton
F) Large eyes

Answer 22

e) partially ossified skeleton

Question 23

What is a distinctive feature of Acanthodii regarding their body covering?
A) They have dermal bone exterior
B) They possess overlapping placoid scales
C) Their body is covered in ganoid scales
D) They lack any scales

Answer 23

c) their body is covered in ganoid scales

Question 24

Which geological era did Acanthodii emerge in?
A) Mesozoic
B) Paleozoic
C) Cenozoic
D) Precambrian

Answer 24

b) paleozoic era in the ordivician period

Question 25

What is the main defining feature of Osteichthyes? A) Presence of cartilage in the skeletal structure B) Presence of scales covering the body C) Presence of bone within the skeletal structure D) Lack of fins for locomotion

Answer 25

c) presence of bone within the skeletal structure - endoskeleton

Question 26

How many species are estimated to belong to the class Osteichthyes? A) 1000 species B) 2000 species C) 3000 species D) 4000 species

Answer 26

d)4000 species !

Question 27

What is the function of the swim bladder in Osteichthyes? A) Excretion of waste products B) Reproduction C) Control of buoyancy in water D) Digestion of food E) Control breathing in water

Answer 27

c) Control buoyancy in water

Question 28

Which group of fish, known for their lung-like swim bladders, belongs to the subclass Sarcopterygii? A) Sharks B) Lungfish C) Tuna D) Salmon

Answer 28

b) Lungfish

Question 29

Which subclasses of Osteichthyes includes fish with ray-finned fins? A) Actinopterygii & Scarcopterygii B) Sarcopterygii & Neopterygii C) Paleonisciformes & Actinopterygii D) Paleonisciformes & Neopterygii

Answer 29

c) Actinopterygii & Paeloniciformes

Question 30

Which subclass of jawed vertebrates possesses lepidotrichia in their fins? A) Actinopterygii B) Sarcopterygii C) Neopterygii D) Paleonicifromes E) Acanthodians

Answer 30

A) Actinopterygii

Question 31

Actinopterygii, a subclass of jawed vertebrates, is divided into two superorders: Paleonisciformes and Neopterygii. Which superorder represents the more ancient lineage among ray-finned fishes? A) Paleonisciformes B) Neopterygii C) Both superorders emerged simultaneously D) There is insufficient evidence to determine the relative ages of the two superorders

Answer 31

A) Paleonisciformes - primitve 'ray-finned' fish

Question 32

The Acanthodians and Paleonisciformes share what common feature? A) Presence of bony scales B) Lepidotrichia in their fins C) Presence of a swim bladder D) Homocercal tail e) Ganoid scales

Answer 32

e) Ganoid scales

Question 33

Which characteristic is NOT associated with the superorder Paleonisciformes? A) Ganoid scales B) almost completely cartilagenous notochors/body C) Heterocercal tail D) Ossified neural arch

Answer 33

A) Ganoid scales

Question 34

Which group of Actinopterygian fish shares a characteristic feature with Chondrichthyes, possessing a cartilage body? A) Sturgeons B) Gars C) Sharks D) Perch

Answer 34

A) Sturgeons

Question 35

What feature do Chondrichthyes and Paleonisciformes share in common? A) Presence of ganoid scales B) Filter-feeding mechanism C) Heterocercal tail D) Lack of paired fins

Answer 35

C) Heterocercal tail

Question 36

In which vertebrate group do we see the notochord increasingly ossified or being replaced? A) Chondrichthyes B) Actinopterygii C) Paleonisciformes D) Neopterygii

Answer 36

D) Neopterygii

Question 37

Here's a multiple-choice question based on the provided information: Which subclass of fish is known for giving rise to the first terrestrial vertebrates? A) Actinopterygii B) Chondrichthyes C) Temnospondyls D) Sarcopterygii

Answer 37

d) Scarcopterygii

Question 38

True or False? Early forms of scarcopterygians had heterocercal tails

Answer 38

true! later forms had diphycercal tails

Question 39

What type of tail did early forms of Sarcopterygii possess? A) Heterocercal B) Homocercal C) Diphycercal D) Placoid

Answer 39

A) Heterocercal

Question 40

What type of scales are characteristic of Sarcopterygii? A) Ganoid scales B) Placoid scales C) Cycloid scales D) Cosmoid scales

Answer 40

d) Cosmoid scales

Question 41

What significant anatomical feature do Sarcopterygii possess in their fins? A) Cartilaginous elements B) Bony elements C) Lack of fins D) Lepidotrichia

Answer 41

d) bony elements

Question 42

What is a characteristic feature of coelacanths? A) Cartilaginous skeleton B) Absence of a swim bladder C) Prominent notochord D) Presence of ganoid scales E) Swim bladder filled with oil

Answer 42

E) Swim bladder filled with oil