Vertebrate zoology (02 bony fishes, student version)

OSTEICHTHYES – BONY FISHabout 97% of living fishes - Class Actinopterygii: ray-finned fishes.. Subclass Chondrostei7 Primitive ray-finned fishes + Skeleton primarily cartilage; caudal fin he

Trang 1

Vertebrate Zoology

Fishes

1

OSTEICHTHYES – BONY FISH

2

3

+ Bony vertebrae replace the notochord

+ The notochord may become enclosed in the

centrum, or more usually is lost

Basic vertebrate (Kardong, 2009; p 82, 300)

Trang 2

about 97% of living fishes

- Class Actinopterygii: ray-ﬁnned ﬁshes

- Class Sarcopterygii: lobe-ﬁnned ﬁshes.

4

CLASS ACTINOPTERYGII

5

Class Actinopterygii (ak’ti-nop-te-rij’ee-i) (Gr aktis, ray, pteryx, ﬁn,

wing): ray-ﬁnned ﬁshes

+ Subclass Cladistia (clə-dis’tē-a) (Gr cladi, branch): bichirs.

+ Subclass Chondrostei (kon-dros’tē-ī) (Gr chondros, cartilage, osteon,

bone): paddleﬁshes, sturgeons

+ Subclass Neopterygii (nee’op-te-rij’ee-i) (Gr neo, new, pteryx, ﬁn,

wing): gars, bowﬁ n, teleosts

Subclass Cladistia

6

Bichir, Polypterus bichir, of equatorial West Africa

A nocturnal (night active) predator

Primitive ray-ﬁnned ﬁshes

+ Have rhombic heavy ganoid scales;

lungs; spiracle present;

+ Dorsal ﬁn consisting of 5 to 18 ﬁnlets

+ About 16 species, freshwater

Trang 3

Subclass Chondrostei

7

Primitive ray-ﬁnned ﬁshes

+ Skeleton primarily cartilage; caudal ﬁn

heterocercal; large scutes or tiny ganoid

scales present; spiracle usually present;

+ More ﬁn rays that ray supports

+ 29 species, freshwater and anadromous

(Gr anadromos, running upward).

Subclass Neopterygii

8

+ Skeleton primarily bone; caudal ﬁn usually homocercal; scales cycloid,

ctenoid, absent, or rarely, ganoid

+ Fin ray number equal to their supportsin dorsal and anal ﬁns

+ About 28,000 species

9

Early neopterygians (nonteleost neopterygians): Two living genera

+ The bowﬁn, Amia (Gr tunalike ﬁsh)

Live in shallow, weedy waters of the Great Lakes and Mississippi River

basin

Trang 4

10

Early neopterygians (nonteleost neopterygians): Two living genera

+ Gars, Lepisosteus (Gr lepidos, scale, osteon, bone)

- Live in eastern and southern North America

- 7 species are large, ambush predators with elongate bodies and

jaws ﬁlled with needlelike teeth

11

The modern bony fishes: teleosts (Gr teleos, perfect, osteon, bone)

+ Representing about 96% of all living ﬁshes or about half of all vertebrates

+ Heavy dermal armor of primitive ray-ﬁnned ﬁshes was replaced by light,

thin, flexible cycloid and ctenoid scales (some lack scales).

+ Homocercal caudal fin

12

+ Teleosts range in size from 7 mm adult minnows to 17 m oarﬁsh and 900

kg, 4.5 m blue marlin.

Trang 5

13

+ Occur from elevations up to 5200 m in Tibet to 8000 m below the surface

of the ocean

14

+ Some species live in hot springs at 44 0C, while others live under the

Antarctic ice at - 2 0C

15

+ may live in lakes with salt concentrations three times that of seawater,

caves of total darkness, swamps devoid of oxygen, or even make extended

excursions onto land (mudskippers)

Almost every

conceivable habitat

Trang 6

Characteristics of Class Actinopterygii

1 Skeleton with bone of endochondral origin; caudal ﬁn heterocercal

in ancestral forms, usually homocercal in descendant forms; skin with

mucous glands and embedded dermal scales; scales ganoid in

ancestral forms, scales cycloid, ctenoid or absent in derived forms

16

2.Paired and median ﬁns present, supported by long dermal rays

(lepidotrichia);muscles controlling ﬁn movement within body

17

3 Jaws present; teeth usually present with enamaloid covering; olfactory

sacs do not open into mouth; spiral valve present in ancestral forms,

absent in derived forms

18

Trang 7

4 Respiration primarily by gills supported by arches and covered with an

operculum

19

5 Swim bladder often present with or without a duct connecting to

esophagus, usually functioning in buoyancy

20

6 Circulation consisting of a heart with a sinus venosus, an undivided

atrium, and an undivided ventricle; single circulation; typically four

aortic arches; nucleated erythrocytes

21

Atrium

Ventricle

Trang 8

7 Excretory system of paired opisthonephric kidneys; sexes usually

separate; fertilization usually external; larval forms may differ greatly

from adults

22

7 Excretory system of paired opisthonephric kidneys; sexes usually

separate; fertilization usually external; larval forms may differ greatly

from adults

8 Nervous system of a brain with small cerebrum, optic lobes, and

cerebellum; 10 pairs of cranial nerves; three pairs of semicircular

canals

23

CLASS SARCOPTERYGII

24

Class Sarcopterygii (sar-cop-te-rij’ee-i) (Gr sarkos , ﬂesh, pteryx, ﬁn,

wing): lobe-ﬁnned ﬁshes

+ Powerful jaws;

+ Heavy, enameled scales with a dentinelike material called cosmine;

+ Strong, ﬂeshy, paired lobed ﬁns - used to clamber over benthic

substrates ﬁlled with woody debris

Trang 9

CLASS SARCOPTERYGII

25

Class Sarcopterygii (sar-cop-te-rij’ee-i) (Gr sarkos , ﬂesh, pteryx, ﬁn,

wing): lobe-ﬁnned ﬁshes

+ Lungfishes: 6 species

+ Coelacanths: Latimeria 2 species

Lungfish

26

+ Neoceratodus (Gr neos, new, keratos , horn, odes, form), the living

Australian lungﬁsh, may attain a length of 1.5 m

+ Lepidosiren (L lepidus, pretty, siren, mythical mermaid): South American

lungﬁsh

+ Protopterus (Gr. prōtos, ﬁrst, pteron, wing): African lungfish

Coelacanths

27

The tail is diphycercal but possesses a small lobe between the upper

and lower caudal lobes, producing a three-pronged structure

The last coelacanths were believed to have become extinct 70 million

years ago

The remains of a coelacanth were found on a dredge off the coast of

South Africa in 1938

The new species of coelacanth was found in Sulawesi, Indonesia,

10,000 km from the Comoros in 1998

Trang 10

28 (Kardong, 2009; p.101)

Sarcopterygians:

(a) Dipterus, fossil lungfish of the

Devonian Note the heterocercal tail.

(b) Osteolepis, a rhipidistian of the

Devonian that also had a

heterocercal tail.

(c) Latimeria is a living sarcopterygian

(coelacanthiformes) exhibiting a

diphycercal tail.

Characteristics of Class Sarcopterygii

1 Skeleton with bone of endochondral origin; caudal ﬁn diphycercal

in living representatives, heterocercal in ancestral forms; skin with

embedded dermal scales with a layer of dentinelike material,

cosmine, in ancestral forms

2.Paired and median ﬁns present; paired ﬁns with a single basal

skeletal element and short dermal rays; muscles that move paired ﬁns

located on appendage

29

3 Jaws present; teeth are covered with true enamel and typically are

crushing plates restricted to palate; olfactory sacs paired, may or

may not open into mouth; intestine with spiral valve

4 Gills supported by bony arches and covered with an operculum

30

Trang 11

5 Swim bladder vascularized and used for respiration and buoyancy

(fat-ﬁlled in coelacanths)

6 Circulation consisting of heart with a sinus venosus, two atria, a

partly divided ventricle, and a conus arteriosus; double circulation

with pulmonary and systemic circuits; characteristically ﬁve aortic

arches

31

7 Nervous system with a cerebrum, a cerebellum, and optic lobes; 10

pairs of cranial nerves; three pairs of semicircular canals

8 Sexes separate; fertilization external or internal

32 Kardong, 2009; p 647

Định dạng
Số trang	11
Dung lượng	4,06 MB