Flashcards in Chapter 24: Fishes Deck (17):
What are the five classes of Fishes?
Describe the very general characteristics of a modern fish! (3)
- aquatic vertebrate with gills, limbs (if present) in the form of fins, skin covered in scales of dermal origin.
Do fishes form a monophyletic group?
- no they do not
- in evolutionary terms, they can be defined as all vertebrates that are not tetrapods.
Fishes share a common ancestor with what?
They have adapted to live in a medium that is ___ times denser than air.
They can adjust to the __ and __ balance of their environment.
Gills are efficient at extracting oxygen from water that has __/__ the oxygen of air
What does their lateral line system detect?
- detects water currents and vibrations, a sense of "distant touch"
How did an evolution in an aquatic environment affect this group?
- it shaped and constrained its evolution
The term "fish(es)" refers to what?
- one or more individuals of one species or to more than one species.
What are the earliest fish like vertebrates categorized as? What does this category contain? EX!
- Agnathans (jawless)
- Extinct ostracoderms
- Living Hagfishes- lack vertebrae
- Lampreys which have rudimentary vertebrae
What is the phylum and subphylum of these classes?
Those that do not belong to the category Agnathans belong to what category? Characteristics?
- paired appendages and join tetrapods as a monophyletic lineage of gnathostomes.
- What fossil record do they belong to?
- Are there intermediate forms between agnathans and this group?
- What time period is called the Age of Fishes?
- Lost ____ and adopted ___.
- Flourished during the ___ and ___ periods
- They almost became extinct at what period?
-They increased in numbers in the early ___ and diversified to form a modern ___ assemblage.
- heavy dermal armour, skeleton of cartilage
- end of the Paleozoic
- What are the two distinct lineages? Describe them!
- Ray-Finned lineages: radiated to form modern bony fishes
- Lobed- finned fishes: relict group with few species today they include the sister group of the tetrapods.