EBIO 4050 Fish Bio Exam 3 Study Guide Answers

WIP with class 2026 spring

For each of the continents of North America, South America, Africa, Eurasia, and Australia, indicate the presence or absence of the orders Cypriniformes, Characiformes, and Siluriformes.

North America: all three present
South America: Characiformes and Siluriformes present
Africa: all three present
Eurasia: Cypriniformes and Siluriformes present
Australia: Siluriformes present

List one synapomorphy for Siluriformes

The absence of scales

List one synapomorphy for Gymnotiformes

A greatly elongated anal fin

List four superorders of the Cohort Euteleostei

Ostariophysi, Protacanthopterygii, Stenopterygii, and Acanthopterygii

List two orders of the Superorder Protacanthopterygii

Salmoniformes and Esociformes

Briefly describe how to distinguish among the salmonid genera Salmo, Oncorhynchus, and Salvelinus. Provide an example of a species in each genus (common name is acceptable)

Salmo: vomerine teeth on the head and shaft of the vomer; Atlantic salmon
Oncorhynchus: vomerine teeth on the head only; rainbow trout
Salvelinus: vomerine teeth on the head only, and are depressible; brook trout

Briefly describe two ways in which the study by Metcalf et al. (2012) challenged the previous view of cutthroat trout diversity in the Southern Rockies

Revised the number and identity of distinct lineages and also challenged the role of post-glacial dispersal in their distribution

Describe the diversity of the Esociformes

It contains Esocidae, large ambush predators with a duck-bill snout, and Umbridae, small hardy fishes in cold environments

What is unusual about the number of dorsal and anal fins and the position of pelvic fins in many members of the Gadiformes?

Multiple dorsal and anal fins present, with their pelvic fins in the jugular or mental position

Briefly describe two unique modifications of tubular eyes in the Opisthoproctidae (barreleyes or spookfishes within the Argentiniformes)

A second lens allows the eye to image light coming from the side and above, along with rotatable eyes, greatly expanding their visual field

Describe two features of the general appearance of stomiiforms and indicate the habitat in which you would expect to find them

A large gaping mouth with long fang-like teeth. Found in the deep mesopelagic and bathypelagic in the dark

What is the common name of the order Myctophiformes and on what feature is it based?

Lanternfishes based off of photophores along the head and body

List two cypriniform families native to Colorado

Cyprinidae and Catostomidae

Briefly describe the “Asian carp” (bighead and silver carp) problem in the United States

Have invaded the US and react violently to boat motors by jumping out of the water onto boats. Presents a real risk of injury to boaters due to their size

List one synapomorphy for Cypriniformes

A weberian apparatus from swim bladder to ear

List one synapomorphy for Characiformes

Fully toothed and fixed premaxilla

What is the principal distinction between unculi and nuptial tubercles?

Unculi are unicellular vs nupital are multicellular keratinized epidermal projections

List a synapomorphy of the Superorder Acanthopterygii

Spines in the pelvic fin

List five orders in the Superorder Acanthopterygii and provide an example of each

Gasterosteiformes; three-spined stickleback
Scorpaeniformes; lionfish
Perciformes; largemouth bass
Pleuronectiformes; Atlantic halibut
Tetraodontiformes; pufferfish

List three orders of teleosts that are bioluminescent and describe the photophores of each

Stormiiformes possess simple to complex photophores with species-specific patterns.
Myctophiformes possess simple species and sex-specific arrangements of photophores.
Aulopiformes possess simple photophores.

Describe inquiline behavior in pearlfishes (Ophidiiformes: Carapidae)

It is a relationship in which they live inside the anus of sea cucumbers and leave at night to feed

What structure is modified for brooding embryos in kurtids (nurseryfishes)?

A boney hook on the back of the skull

What feature is shared by many members of the Ovalenteria?

Demersal adhesive eggs with chorionic filaments

List four orders of fishes within the Ovalenteria and provide an example of each

Cichliformes, nile tilapia
Atheriniformes, jacksmelt
Cyprinodontiformes, guppy
Beloniformes, Atlantic flying fish

Briefly describe two features of flight in flying fishes that allow them to glide up to 400 m

An elongated lower lobe of their caudal fin allows them to propel themselves out of the water and large pectoral fins act as wings

Briefly describe how ontogeny recapitulates phylogeny in the Beloniformes

Changes in jaw development from larva to adult reflects that of the evolution of the jaw. Flat face in larva, to lower jaw being pointed in juveniles, to both lower and upper being pointed in adults.

List two families within the order Cyprinodontiformes (killifish)

Cyprinodontidae and Poeciliidae

What reproductive strategy is shared by members of the Embiotocidae?

Live birth

Briefly describe how some pomacentrids (damselfishes) can be considered to engage in “farming” and “ranching.”

They defend and farm a garden of algae on which they feed and ranch shrimp inside of

Briefly describe an unusual means by which at least one species of cichlid feeds its young.

Parents produce slime that the larva feed off of

Briefly describe four interesting aspects of the evolution of cichlids.

1. High levels of hybridization rapidly gave rise to new species
2. Very phenotypically diverse
3. Hundreds of species evolved in a short time
4. Many species independently evolved similar traits in separate lakes

List two orders in the Carangimorpharia and provide an example of each.

Carangiformes, jacks
Istiophoriformes, barracudas

List an unusual behavior of members of the family Echeneidae.

They use a modified dorsal fin that acts as a suction disc to attach themselves to large hosts such as sharks

What are two uses of air by anabantoids?

Breathing and enhancing hearing

How would you recognize a member of the order Pleuronectiformes?

Bilaterally asymmetrical and a very compressed body shape

Which sex has the brood pouch in the syngnathiform family Syngnathidae(includes seahorses)?

Males

Provide a brief explanation of the unusual shape of the head of seahorses

Minimizes water disturbance when snapping head forward for hunting prey

Briefly describe the uses of the pectoral and pelvic fins in the Dactylopteridae (flying gurnards)

Bright defense colors with pectoral fin and walks across the floor with pelvic fins

Briefly describe the role of hydraulics in the control of tuna fins

Compressing or uncompressing muscles moves fluid to raise or lower their fins

What is a potential function of the mucous cocoon produced by scarids?

Protection against mosquitos

List two families in the order Perciformes native to Colorado and give an example of each

Percidae, Johnny Darter
Centrarchidae, Green Sunfish

List two unusual morphological features found within the Notothenioidei (icefishes)

Lack of swim bladder and hemoglobin

Briefly describe the “Lionfish Invasion.”

The invasion into the Atlantic Ocean, Gulf of Mexico, and Caribbean Sea

Provide two examples of members of the Order Scorpaeniformes, including one that is native to Colorado

Lionfish and Mottled Sculpins

Name one feature that has evolved in parallel in threespine stickleback (Gasterosteus aculeatus) populations that have invaded freshwater from the marine environment

The reduction or loss of the pelvic girdle and pelvic spines

Why are acanthurids called surgeonfishes?

Because they have a spine on their caudal peduncle

List the names of the two components of the “angling” apparatus in Lophiiforms

Illicium and esca

List one unusual morphological structure and one unusual behavioral feature of male ceratioid anglerfishes

Large olfactory apparatus and will latch onto and fuse to the female circulatory system

List the common or scientific names of two families of the Tetraodontiformes

pufferfish and triggerfish

Describe an unusual reproductive behavior described in a species of male pufferfish

Make circular structures in sand to attract a mate

Are sharks older than trees? Justify your answer by commenting on stem groups and crown groups within the Chondrichthyes

The species alive then are more likely to be the stem group of Chondrichthyans rather than sharks due to their age

List one distinctive feature of placoderms

Bony armor plates covering the head and thorax

List one distinctive features of acanthodians

Strong spines on the leading edge of all fins except the caudal fin

What do the discoveries of placoderms with osteichthyan (bony fish)-like marginal jaw bones imply about the dermal skeleton of the last common ancestor of bony and cartilaginous fishes?

Stem Group Placoderms had bony dermal jaw bones, showing the common ancestor had dermal bone. Crown Group Chondrichthyes lack dermal bone. Stem groups preserve ancestral features that crown groups may have lost.

What is an “ostracoderm”?

Extinct, armored, jawless fishes from the Paleozoic Era

What are Crown Groups?

All living species and their most recent common ancestor

What are Steam Groups?

Extinct species that are more closely related to a crown group than to any other living species

What is the currently accepted view of the relationships of hagfishes, lampreys, “ostracoderms” and gnathostomes, and what are the implications of this view for the evolution of paired fins and dentine?

Hagfishes and lampreys are the sister group to Gnathostomes. Ostracoderms are various stem gnathostomes; extinct lineages that branched off before crown gnathostomes but after the cyclostome split. The implications of this are that stem groups show that paired fins and dentine are older than jaws.

Briefly describe the evolution history of lampreys inferred from fossils in terms of the origin of the body plan, the ancestral habitat, the origin of the parasitic/predatory lifestyle and the origin of metamorphosis.

What is one line of evidence from the fossil record that modern hagfishes are degenerate?

The eye in found fossils suggest they were more advanced and degenerated to what we have today

What are Myllokunmingiids and Euconodonts and what are their relationships to hagfishes, lampreys and gnathostomes?

Myllokunmingiids are soft-bodied animals from the Caribbean, stem group vertebrates. Euconodonts are jawless vertebrates with mineralized tooth elements, lost that in lampreys and gnathostomes.

What feature of the paired fin skeleton distinguishes (most) sarcopterygians from actinopterygians?

Sarcopterygians have an extended internal skeleton in the fin; actinopterygians have fin rays directly supported by multiple basals

List one major group of sarcopterygians with an intracranial joint

Actinistia

List one major group of sarcopterygians in which heterocercal tails were transformed into diphycercal ones

Actinistia

Briefly describe a feature that suggests that Eusthenopteron is more closely-related to tetrapods than are lungfishes and coelacanths

The possession of openings on the palate that connect the nasal cavity to the mouth

List three major features of the transition from fish to tetrapod

Loss of fin rays, development of the neck, and a differentiated vertebral column

What is the evolutionary significance of Tiktaalik roseae?

Shows how limbs evolved from fins

What are the three most common groups of living jawed vertebrates? When did they achieve their numerical dominance over other living and extinct forms?

Teleosts, Elasmobranchs, and Holocephalans in the late Cretaceous

List one distinctive feature of palaeoniscoids

Ganoid scales

Which living non-teleostean fishes most closely resemble the dominant ray-finned fishes of the Mesozoic Era

Gars and bowfin

During what Geological Period did crown group teleosts appear?

Cretaceous

What happened to spiny-rayed teleosts at the end of the Cretaceous and beginning of the Tertiary (Paleocene)?

Explosive adaptive radiation

Distinguish between oviparous and viviparous

Eggs vs live birth

Distinguish between lecithotrophic and matrotrophic

Relying on nutrients from yolk vs nutrients from mother

List three methods by which the mother may provide nutrients to developing embryos in matrotrophic fishes

Placenta, urine, and oophagy

List two structures present at the pharyngula stage of teleost development that make it a phylotypic stage

Pharyngeal arches and notochord

Briefly describe the Epiboly type of cell movement that occurs during teleost development

Cells moving as a sheet

Briefly describe the Involution type of cell movement that occurs during teleost development

Cells outside the embryo moving underneath layers

Briefly describe the Convergence type of cell movement that occurs during teleost development

Cells moving to the center

Briefly describe the Extension type of cell movement that occurs during teleost development

Cells “leaving the theater” after converging

List two structures that are derived from somites

Vertebrae and muscle segments

List three cell types or structures that are derived from neural crest

Pigment cells, teeth dentine, and neurons