Name ___________________________________
Lab 9 - An introduction to marine fishes
NOTE: these taxonomic groups have many more species than those shown today; each specimen is but a
representative of its particular family or order. PLEASE HANDLE SPECIMENS CAREFULLY!!!!
Superclass Agnatha (jawless fishes; ~80 spp.)
Class Myxini
Order Myxiniformes
Family Myxinidae; Hagfish (Myxine glutinosa)
Class Cephalaspidomorphi
Order Petromyzontiformes
Family Petromyzontidae; Sea lamprey (Petromyzon marinus)
1) What are some key differences between Myxinids and Petromyzontids?
Superclass Gnathostomata (jawed fishes)
Class Chondrichthyes (cartilaginous fishes)
Subclass Elasmobranchii (shark-like fishes; 800 spp)
Order Squatiniformes; Angel shark (Squatina dumerili)
Order Squaliformes; Spiny dogfish (Squalus acanthias)
Order Rajiformes; Clearnose skate (Raja eglanteria), Guitarfish (Rhinobatos sp.)
Subclass Holocephali (chimaeras; 30 spp)
Order Chimaeriformes; Spotted chimaera (Hydrolagus colliei)
2) What are two features that clearly distinguish the order Rajiformes (skates) from sharks?
3) Where in the water column would you expect to find a chimaera? Why?
Class Teleostomi (bony fishes)
Superorder Clupeomorpha
Order Clupeiformes
Family Clupeidae; Atlantic herring (Clupea harengus), Menhaden (Brevoortia tyrannus)
Family Engraulidae; Anchovy (Anchoa nasuta)
4) What characteristics most clearly separate these two families?
5) These fishes tend to travel in schools. What purpose might the silvery stripe down their sides serve?
(Hint: think about this from the perspective of a predator!)
Superorder Elopomorpha
Order Anguilliformes
Family Muraenidae; Moray eel (Gymnothorax nigromarginatus)
Family Anguillidae; American eel (Anguilla rostrata)
6) Compare and contrast these two types of eels. How do their fins compare? Their teeth?
Superorder Stenopterygii
Order Stomiiformes
Family Sternoptychidae; Hatchetfish (Argyopelecus lynchus)
Superorder Aulopomorpha
Order Aulopiformes
Family Synodontidae; Lizardfish (Trachinocephalus myops)
Superorder Myctophomorpha
Order Myctophiformes
Family Myctophidae; Lanternfish (Lampanyctus mexicanus)
7) The orders Stomiiformes and Myctophiformes all live in similar habitats. What are the most striking
characteristics of these fishes? Based on those characteristics, in which ocean habitat zone would you
expect these fishes to live?
8) Hatchetfish and lanternfish are among the most abundant fishes on the face of the Earth. Why might that
be? (Hint: think about your answer to #7, and what you’ve learned about the different types of oceanic
habitats.)
9) The fishes in #8 are often caught at night in near-surface waters. Does that change your answer to #8?
Why?
10) Look at the body and mouth of the lizardfish. Where do you think it lives, and what does it feed on?
Superorder Paracanthopterygii
Order Gadiformes
Family Gadidae; Spotted hake (Urophycis regia), Walleye pollock (Theragra
chalcogramma)
11) These fishes are relatives of the burbot (Lota lota), which lives in Wisconsin. Look at your notes on
burbot. What similar traits do these fishes share with burbot? Any differences?
Order Lophiiformes
Family Ogcocephalidae; Batfish (Ogcocephalus sp.)
12) These fish are lie-and-wait predators that use a “lure” (the esca) at the end of a “fishing pole” (the
illicium) to attract their prey. List some of the other morphological features they have that help them
in this feeding mode.
13) Batfish have very large mouths. What advantage does that serve? (An obvious advantage to having a
large mouth is that you can fit large prey items into it—larger goosefishes have been found to eat small
sharks and even birds—but I’m looking for something else.)
Order Batrachoidiformes
Family Batrachoididae; Plainfin midshipman (Porichthys notatus)
14) This fish has 700-800 photophores (light-producing organs) on its body, but it lives in relatively
shallow water. Speculate on the purpose of these photophores.
Superorder Acanthopterygii
Order Beloniformes
Suborder Exocoetoidei
Family Exocoetidae; Flying fish (Cyprelurus heterurus)
Family Hemiramphidae; Halfbeak (Hyporhamphus unifasciatus)
15) Look closely at these families…they are rather closely related (some taxonomists even lump them into
one family). What are their morphological similarities? What are the differences?
16) The caudal fins of these fishes are often heterocercal, but not in the same way we’ve seen this
semester. Why would they be “reverse heterocercal”?
Order Gasterosteiformes
Family Syngnathidae; Lined seahorse (Hippocampus erectus), Dusky pipefish
(Syngnathus floridae)
Family Aulorhynchidae; Tubesnout (Aulorhynchus flavidus)
17) See if you can identify the dorsal, anal, pectoral, pelvic, and caudal fins on these fishes. Do they have
all of these fins? What is the primary locomotory fin for each fish?
18) None of these fishes swim very quickly. What adaptations do they have in place of speed for predator
avoidance?
Order Scorpaeniformes
Family Scorpaenidae; Lionfish (Pterois volitans)
Family Triglidae; Sea robin (Prionotus carolinus)
Family Cottidae; Buffalo sculpin (Enophrys bison), Little dragon sculpin (Blepsias
cirrhosus)
19) Take a look at the diversity in coloration, texture, spines, and fins on these fishes. Why do you
suppose the lionfish is so much more colorful and “obvious” than the other fishes of this order?
20) What do you suppose the purpose is of the sea robin’s pectoral fins?
Order Perciformes
Suborder Percoidei
Family Serranidae; Red hind grouper (Epinephelus merra)
Family Lutjanidae; Yellow snapper (Lutjanus argentiventris)
Family Carangidae; Round scad (Decapterus punctatus)
21) What general similarities do you notice among these fishes? (You see some of these features in the
Perciforms of Wisconsin, like yellow perch, walleye, and largemouth bass.)
22) Which of these families would win a 100-meter race? Which would finish last? Why?
Order Perciformes
Suborder Scombroidei
Family Scombridae; Mackerel (Scomber scombrus)
23) This fish is evolved for continuous, fast swimming. Describe some traits that help it swim quickly and
efficiently.
Order Pleuronectiformes
Family Soleidae; Hogchoker (Trinectes maculatus)
Family Paralichthyidae; Ocellated flounder (Citharichthys macrops)
Family Pleuronectidae; Yellowfin sole (Limanda aspera)
Family Cynoglossidae; Tonguefish (Symphurus sp.)
24) What characteristics distinguish the families?
25) Look at both sides of these fishes. Note the positions of the paired fins, the position of the lateral line,
the orientation of the mouth, and the coloration. Now, think about where the eyes are. Are these
fishes compressed in the lateral plane or the dorsal/ventral plane?
Order Tetraodontiformes
Suborder Balistoidei
Family Balistidae; Queen triggerfish (Balistes vetula), Gray triggerfish (Balistes
capriscus)
Suborder Tetraodontoidei
Family Tetraodontidae; Pufferfish (Sphoeroides maculatus)
Family Diodontidae; Striped burrfish (Chilomycterus schoepfi)
26) Believe it or not, this Order contains the most highly derived fishes known. “Tetra” means four, and
“dont” means teeth. Take a good look at their teeth, if possible; what do you suppose these fishes eat?
27) Examine the dorsal fin of a triggerfish. What do you notice? What significance might this have for
triggerfish ecology?
28) Both puffers and porcupine fishes are very slow swimmers, and are potentially vulnerable to predators,
even when they inflate their bodies. Which of these fishes appears better defended against predation?
Given your answer to that question, how is it that the “less-protected” fish has not been eaten into
extinction?