WFC120 week 4 & 5

fq ucd 2026

TRUE or FALSE: All Sarcopterygian and ancient Actinopterygian fishes have functional lungs.

true

Several Sarcopterygian and ancient Actinopterygian fishes are found in water with low oxygen concentrations. What is the anatomical adaptation that allows them to survive in poorly oxygenated water?

lungs or highly vascularized swim bladders

Which type of scales are characteristic of ancient Actinopterygians?

ganoid

External fertilization is a feature of all ancient Actinopterygians. Therefore, they all must be ____________.

oviparous

What has been the main driver of overfishing and poaching for sturgeon?

demand for sturgeon roe (caviar)

Which sturgeon species are found in California?

White sturgeon,Green sturgeon

What caused a spike in sturgeon mortality in 2022 and mobilized sturgeon scientists to increase conservation action?

harmful algal bloom (HAB)

Which of the following is true about Putah Creek?

Lower Putah Creek fish habitat has degraded since 1996

After restoration of salmon spawning habitat and restoration to a more natural flow regime in Putah Creek, Chinook salmon began spawning in Putah Creek. Hitt et al. (2024) found that in subsequent years, the offspring of those salmon returned to Putah Creek to spawn. Which of the following best describes the importance of these findings?

 

This study demonstrates that the restoration strategies used in Putah Creek effectively allowed a salmon population to establish and complete their life cycle in the restored area.

Examples of fish sampling gear commonly used in scientific study of fishes?

trawl nets, fyke nets, electrofishers, seines, rotary screw traps

hagfish commercial use

food in korea, luxury leather goods, commercial fishery

hagfish conservation status

20% hagfish species at risk, 2 sp endangered (IUCN)

hagfish threats

overexploitation, habitat decline, bottom trawl fishing, no

Which of the following is NOT true about hagfish?

C) Hagfish only eat live prey

lamprey Morphology + Physiology

eyes only in adults, 7 gill pores, oral disc, single nostril, additional photo sensory organ

7 gill pores in lampreys

Water enters + exits via gill pores. Facilitates ‘breathing’ while feeding parasitically

lamprey oral dics

Keratinized ‘teeth’

lamprey additional photo sensory organ

pineal eye

lamprey in larval phase

freshwater, filter feed, 12+ years

lamprey reproduction

semelparous, nonmigratory/nonparisitic, freshwater

anadramodous species

marine phase in parasitic, blood feeding adults

lamprey importance

nutrient cycling, improve water quality, prey, substrate turnover

Which of the following statements are true? (Select all that apply)

A) Unlike lamprey, all hagfish live in marine environments

B) Unlike hagfish, some lamprey feed parasitically

C) Hagfish and lamprey are closely related to true eels

D) Hagfish and lamprey both use slime as a defense mechanism

A) Unlike lamprey, all hagfish live in marine environments

B) Unlike hagfish, some lamprey feed parasitically

lamprey threats

• Habitat loss (Dams, Channel alteration, dredging, entrainment)

• Climate change

• Contaminants (Mercury, pesticides, PCBs (‘legacy’ pollutants))

• Some species may be overexploited

lamprey commercial use

fisheries in alaska, russia, europe for human and sled dog food

lampreys are vulnerable to

biomagnification through blood (mercury)

West Coast Lamprey Conservation Efforts

Petition for ESA listing; increased research, passages through dams, habitat restoration, Aquaculture/artificial propagation, Translocations/reintroductions, Salvage - dredging/dewatering

PIT (Passive Integrated Transponder)

tagging for juvenile/adult lamprey. PIT-tagged fish swim past antenna, the unique tag ID is recorded

Parentage-based tagging

Genetic approach instead of a physical tag; measures success of

translocations, helps study reproductive behavior

Chondrichthyes

Sharks + Rays + Skates, chimaeras

Chondrichthyes defining features

Jaws, cartilaginous skeletons, paired fins, electroreception, no swim bladder, internal fertilization

Ampullae of Lorenzini

Network of gel-filled pores in skin, detects electric fields in water, evolved directly from the lateral line system,

Fish w/ electroreception

still have lateral line

Detects electric fields in water

Helps locate hidden/buried prey. Aids in predator avoidance. Enhances mate recognition. Helps in navigation

Evolved directly from lateral line system

Mechanoreception – detects water flow

Chimaeras Morphology + Physiology

Few scales on body. Tooth plates. Single gill opening (operculum). Deep-sea fish. bulky eyes + large heads, tapering tails,

chimera ecology

deep sea fish, internal fertilization, iteroparous, slow growth

chimera ecological importance

population control (benthic inverbebrates), integrate into benthic food webs, substrate turnover

chimera conservation status

8 at risk species, threatened by bycatch, habitat decline, low reproductive output, very low conservation effort (hard to study)

Sharks + Rays + Skates morphology

Covered in placoid scales. Serially replacing teeth. 5-7 gill openings (No operculum). Primarily marine

Which of the following is a NOT a defining characteristic of

Chondrichthyes?

A) Cartilaginous skeleton

B) Internal fertilization

C) Electroreception/Ampullae of Lorenzini

D) Double-chambered swim bladder

D) Double-chambered swim bladder

chimaera Morphology + Physiology

Which of the following is NOT a defining characteristic of the superclass Agnatha?

 

1. Absence of paired fins

 

2. Absence of jaws

 

3. Presence of swim bladder

 

4. Cartilaginous skeleton

3. Presence of swim bladder

Which of the following are examples (covered in lecture) of conservation efforts conducted for West Coast lampreys (typically Pacific lamprey)? (Select all that apply)

 

1. Salvage to prevent mortality during dewatering and/or dredging

 

2. Catch & release rules and commercial fleet restrictions

 

3. Lamprey-specific passage structures at dams

 

4. Aquaculture

 

5. Translocation and reintroductions

 

6. Requirements for specialized equipment on commercial fleets to prevent bycatch

1. Salvage to prevent mortality during dewatering and/or dredging

 

3. Lamprey-specific passage structures at dams

 

5. Translocation and reintroductions

 

6. Requirements for specialized equipment on commercial fleets to prevent bycatch

Which of the following is NOT true?

 

1.Chondrichthyes includes chimaeras (Holocephali) and sharks, skates, and rays (Elasmobranchii)

 

2. All cartilaginous fishes (Chondrichthyes) are viviparous (live birth rather than egg laying)

 

3. All cartilaginous fishes (Chondrichthyes) have ampullae of Lorenzini

 

4. Elasmobranchs are covered in placoid scales while chimaeras are mostly smooth and scaleless.

2. All cartilaginous fishes (Chondrichthyes) are viviparous (live birth rather than egg laying)

TRUE or FALSE. Both chimaeras and hagfish populations are threatened by bottom-trawl fishing practices.

TRUE

What is an anatomic feature that helps cartilaginous fishes (Chondrichthyes) compensate for their lack of swim bladder?

Very large, fatty liver

What is one factor that compounds the risk of extinction for most cartilaginous fishes (Chondrichthyes)?

low reproductive rate

The broad ‘wings’ present on skates and rays are modified ___________.

pectoral fins

According to Dulvy et al. 2017, whats true about fishing bans

complete bans are appropriate for some species, but many shark species are capable of supporting a significant level of fishing if kept within science-based catch limits

Trophic cascades are a potential consequence of population decline/extinction of apex predators (like many shark species). Which of the following best describes the trophic cascade that occurs when an apex predator is removed?

1. Primary producer populations increase and other species decrease

2. Mid-level predator populations grow unchecked, and populations decline in species at lower trophic levels

3. Overpopulation of all species at lower trophic levels (below apex predator)

4. Mid-level predator populations decrease, and populations boom in species at lower trophic levels

1. Mid-level predator populations grow unchecked, and populations decline in species at lower trophic levels

Which of the following are features of the class Sarcopterygii (excluding tetrapods)? (Select all that apply)

1. cosmoid scales

2. fleshy, muscular fins with robust bony structure

3. cartilaginous skeletons

4. relatively low species diversity

cosmoid scales, fleshy, muscular fins with robust bony structur, relatively low species diversity

Which taxonomic group contains all cartilaginous fishes (Chondrichthyes)

EXCEPT chimaeras?

A) Holocephali

B) Elasmobranchii

C) Galea

D) Squalea

B) Elasmobranchii