30 Questions
What is the function of the protruding oral hood in lampreys?
Funnel water through the muscular pharynx where food particles are trapped in mucus.
At what size and age does an ammocoete undergo major morphological and behavioral changes?
10 centimeters or longer and several years old.
How long is the typical adult life span of a lamprey?
No more than two years.
When did lampreys begin to expand rapidly across the Great Lakes basin?
1920s to the 1950s.
What led to the concern of sporting and commercial interests regarding lampreys?
Reduction of economically important fish species like lake trout, burbot, and lake whitefish.
In which lake were sea lampreys initially unknown before 1921?
Other Great Lakes of North America.
What is the function of the large rocks in the nest constructed by male and female lampreys?
The large rocks rim the upstream pit and downstream mound, creating eddies and oxygenating the water in the nest.
How do lampreys fertilize their eggs during breeding?
The male lamprey wraps around the female, fertilizing the eggs as she lays them.
What is the fate of adult lampreys after they breed?
Adult lampreys die after breeding once.
Describe the appearance of lamprey larvae, known as ammocoetes.
Ammocoetes are tiny, 6- to 10-millimeter-long wormlike organisms with a large oral hood and nonfunctional eyes.
Where do the ammocoetes go after leaving the nest?
The ammocoetes are carried downstream by currents to backwaters and quiet banks where they burrow into soft mud or sand.
What is the purpose of the sand and smaller stones in the nest constructed by lampreys?
The sand and smaller stones downstream of the pit create eddies that oxygenate the water in the nest.
What is the reason 'Ostracoderms' is considered a paraphyletic assemblage?
Some more derived types of ostracoderms are more closely related to gnathostomes (jawed vertebrates) than others.
What distinguishes Ostracoderms from extant agnathans in terms of features like dermal bone and brain structures?
Ostracoderms had dermal bone and gnathostome-like features such as a cerebellum in the hindbrain and an olfactory tract connecting the olfactory bulb with the forebrain.
How did the interpretation of the relationships among different lineages of ostracoderms change over the latter part of the twentieth century?
The interpretation changed considerably as new understanding emerged about how ostracoderms are related to each other and to living vertebrates.
What characterizes most ostracoderms in terms of their physical appearance?
Most ostracoderms are characterized by the presence of dermal bone, usually in the form of an extensive armored shell or carapace.
What was the range of lengths observed in ostracoderms?
Ostracoderms ranged in length from about 10 centimeters to more than 50 centimeters.
How do the olfactory bulbs of ostracoderms differ from those of living agnathans?
In ostracoderms, the olfactory bulbs are placed more anteriorly and linked to the head via the olfactory tract, unlike in living agnathans.
What is the traditional difference between gnathostomes and agnathans?
Presence of jaws that bear teeth and two sets of paired fins or limbs
During what period did the form of the gnathostome lower jaw show the most variability?
Silurian
What improvements in abilities and systems characterize the derived features of gnathostomes?
Improvements in locomotor and predatory abilities, sensory and circulatory systems
What evidence suggests a second Hox duplication event in living jawed vertebrates?
Living jawed vertebrates show evidence of a second Hox duplication event
What group lies between living agnathans and gnathostomes, showing a stepwise acquisition of features?
Extinct ostracoderm taxa
What is the significance of the variety of jaw forms stabilizing by the Devonian?
Major radiation of jawed vertebrates commenced
What is the function of the conus arteriosus in gnathostomes' hearts?
Acts as an elastic reservoir that smoothes out the pulsatile nature of blood flow.
What is the significance of the type of cartilage found in gnathostomes compared to hagfishes and lampreys?
The cartilage in gnathostomes is different and more specialized.
What is a key feature of the reproductive system in gnathostomes?
Gonads have specialized ducts leading to the cloaca.
How do fins aid in the guidance of a body in three-dimensional space?
Fins act as hydrofoils, applying pressure to the water, creating thrust in the opposite direction.
What is the role of a tail fin in propulsion?
Increases the area of the tail, providing more thrust during propulsion.
Why are rapid adjustments of body position important in water?
To maintain balance and control movement efficiently.
Learn about the reproduction process of lampreys, including how female lampreys produce eggs and how both male and female lampreys construct nests. Explore the detailed nesting behavior involved in the life cycle of lampreys.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
