Phylum Chordata: Subphylum Vertebrata - Fishes
16.1
Lab #16 -- Biological Sciences 102 – Animal Biology
THE MOST DIVERSE GROUP OF VERTEBRATES
~ THE FISHES ~
LAB PROCEDURE
NAME:
LAB SCORE:
Refer to the textbook regarding fishes for diagrams, illustrations and
reference text for this lab.
Subphylum Vertebrata or Craniata
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In the space below, briefly describe some important
characteristics of the Subphylum Vertebrata:
Superclass Agnatha
Class Myxini: Hagfish
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In the space below, briefly describe some important characteristics of this class
of vertebrates.
Identify and note the location or importance of the following structures or
lack of structures in a hagfish:
(you should be able to identify a hagfish for the laboratory practicum)
 slime glands
 lack of paired appendages
 lack of any type of gill covering
 single pair of common gill apertures (openings)
 lack of biting jaws
 sensory tentacles around the mouth
 reduced (degenerative eyes)
Phylum Chordata: Subphylum Vertebrata - Fishes
16.2
Lab #16 -- Biological Sciences 102 – Animal Biology
Superclass Agnatha
Class Cephalaspidomorphi
(or Petromyzontida): Lamprey
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In the space below, briefly describe some important
characteristics of this class of vertebrates.
Your instructor will briefly review with you the basic lifecycle of a typical
lamprey.
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How does an ammocoete larva of a lamprey differ from Amphioxus (a cephalochordate)
in its basic structure?
Identify and note the location or importance of the following structures or
lack of structures in a lamprey:
(you should be able to identify a lamprey for the laboratory practicum)
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lack of paired appendages
single, median nasal aperture (opening)
horny teeth around mouth
lack of any scale covering
7 pairs of external gill apertures
(openings)
moderately developed eyes
Phylum Chordata: Subphylum Vertebrata - Fishes
16.3
Lab #16 -- Biological Sciences 102 – Animal Biology
Superclass Gnathostomata
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How do members of the Superclass Agnatha differ from members of the Superclass
Gnathostomata?
 Regarding the basic classification of fishes, be sure you are aware of
the major distinguishing characteristics specific to each of the
following taxa – see the poster and lab handout:
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Class Chondrichthyes
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Subclass Elasmobranchii
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Subclass Holocephali
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Class Sarcopterygii
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Class Actinopterygii
 Provide the taxonomy from Superclass to Order as requested for each
of the following fishes: (this may require that you check ITIS or the
poster displayed in lab).
Salmon
Phylum
Class
Subclass
Superorder
Ratfish
Superclass
Class
Subclass
Dogfish (Squalus)
Subphylum
Class
Subclass
Phylum Chordata: Subphylum Vertebrata - Fishes
16.4
Lab #16 -- Biological Sciences 102 – Animal Biology
Sturgeon
Subphylum
Class
Subclass
Surf Perch
Superclass
Class
Order
Manta Ray
Phylum
Class
Subclass
Lamprey
Superclass
Class
Goldfish
Superclass
Class
Subclass
Infraclass
Examine the model of the coelacanth, Latimeria chalumnae on display.
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What anatomical features might have preadapted the ancestors of this modern species
for a terrestrial existence?
Phylum Chordata: Subphylum Vertebrata - Fishes
16.5
Lab #16 -- Biological Sciences 102 – Animal Biology
 Fish Classification
Of the nearly 51,000 different species of vertebrates, nearly 24,000 are
the various fish species
Phylum Chordata (chordates)
Suphylum Vertebrata (vertebrates; cranium and spinal column/backbone)
Superclass Agnatha (jawless vertebrates; cartilaginous skeleton
with persistent notocord; lack paired fins)
Class Myxini (hagfishes; four pairs of tentacles around
mouth; nasal sac with duct to pharynx; slime glands
present; poorly developed eyes)
Class Cephalaspidomorphi (lampreys; buccal funnel with
keratinized teeth; nasal sac not connected to pharynx;
fairly well developed eyes)
Superclass Gnathostomata (jawed vertebrates; paired
appendages present; partial or complete replacement of
notocord with centra (body) of spinal column)
Class Chondrichythes (fish with a cartilaginous skeleton;
teeth not fused to jaw; no swim bladder; spiral valve in
intestines; claspers in males)
Subclass Elasmobranchii (sharks, skates & rays;
placoid scales usually present; five to seven gill
arches & slits; upper jaw not fused to cranium)
Subclass Holocephali (chimaeras & ratfishes; scales
absent; four gill slits covered by an operculum;
upper jaw fused to cranium)
Class Actinopterygii (ray-finned fishes; ossified
skeleton; single gill opening covered by an operculum;
paired fins supported by dermal rays; limb musculature within
body; swim bladder mainly a hydrostatic organ)
Subclass Chondrostei (bichirs, paddlefishes &
sturgeons; heterocercal caudual fin, ganoid scales if
present; spiral valve in intestines)
Subclass Neopterygii (gars, bowfin, teleosts; bony
skeleton; caudal fin usually homocercal; scales
usually cycloid or ctenoid; fin ray number equal to
their supports in dorsal and anal fins) = most fish
Class Sarcopterygii (lobe-finned fishes; ossified skeleton;
single gill opening covered by operculum; paired fins
with internal skeleton and musculature within the limb;
diphycercal tail; spiral valve in intestines; usually
lung-like swim bladder)
Phylum Chordata: Subphylum Vertebrata - Fishes
16.6
Lab #16 -- Biological Sciences 102 – Animal Biology
 FISH SCALE OBSERVATION:
Briefly observe the following slides of examples of scale types under the microscope, make a
simple sketch of each scale type and list one species displayed in the lab that possesses
this type of scale:
Placoid Scale
Species example =
Ganoid Scale
Species example =
Ctenoid Scale
Species example =
Cycloid Scale
Species example =
 FISH SKELETAL SYSTEM OBSERVATION:
On one of the fish skeletons displayed in lab, identify the following skeletal structures on
a bony fish: (refer to exercise #18 in lab manual)
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otoliths
maxilla
dentary (“mandible”)
operculum
orbit
pectoral girdle
pelvic girdle
vertebrae
ribs
fin rays
Phylum Chordata: Subphylum Vertebrata - Fishes
16.7
Lab #16 -- Biological Sciences 102 – Animal Biology
FISH SPECIMEN OBSERVATION:
For at least 8 of the live or preserved specimens displayed in the lab indicate the following:
1. Genus
Class
Common Name
2. Genus
Class
Common Name
3. Genus
Class
Common Name
4. Genus
Class
Common Name
5. Genus
Class
Common Name
6. Genus
Class
Common Name
7. Genus
Class
Common Name
8. Genus
Class
Common Name
Phylum Chordata: Subphylum Vertebrata - Fishes
16.8
Lab #16 -- Biological Sciences 102 – Animal Biology
DOGFISH (Squalus) SHARK DISSECTION
Refer to the photos on the course website and the supplementary lab atlas regarding this
dissection.
External Structures (entire fish)
 nostril
 eye
 mouth
 spiracle
 external gill slits (how many are there?)
 lateral line
 claspers (which sex has these?)
 caudal peduncle
 cloaca
 ampullae/organs of Lorenzini
 dorsal fins (anterior and posterior)
 pectoral fins
 pelvic fin
 caudal fin
 Why is the dorsal side of the shark darker in color relative to the ventral
side?
Internal Structures
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liver
Why is the liver so important to buoyancy in sharks?
Abdominal Organs
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stomach
rugae of stomach
duodenum
spiral valve
colon
rectal gland
spleen
pancreas (inferior to stomach)
gallbladder
testes
seminal vesicles (males)
ovaries (females)
ductus deferens (males)
oviducts (females)
Phylum Chordata: Subphylum Vertebrata - Fishes
16.9
Lab #16 -- Biological Sciences 102 – Animal Biology
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What is the importance of the spiral valve relative to digestive processes in sharks?
Thoracic Organs
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heart
gill arches
gill rakers
gill filaments
Cranial Structures
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eye
brain
optic nerve
spinal cord
otoliths
LABORATORY NOTES ON THE SQUALUS DISSECTION:
Phylum Chordata: Subphylum Vertebrata - Fishes
16.10
Lab #16 -- Biological Sciences 102 – Animal Biology
PERCH, ROCKFISH OR OTHER BONY FISH DISSECTION
Refer to the supplementary lab atlas and the Internet regarding this dissection.
External Structures (entire fish)
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nostril
eye
mouth
operculum
lateral line
caudal peduncle
cloaca
dorsal fins (anterior and posterior)
pectoral fins
pelvic fin
caudal fin
anal fin
LABORATORY NOTES ON
THE BONY FISH DISSECTION:
Internal Structures
Abdominal Organs
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swim/air bladder
liver
stomach
pyloric cecum
intestine
testes (males)
ovaries (females)
oviducts (females)
Thoracic Organs
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heart
gill arches
gill rakers
gill filaments
Cranial Structures
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eye
brain
spinal cord
Types of fish caudal fins
Teleostei by Haeckel