ICY Exam 2

What layer of skin do the scales of fish emerge from?

The dermis

What are a few derivatives of the epidermis?

Tastebuds, lateral line system, and mucus cells

__ are pearl organs that minnows and suckers have

Nuptial tubercles

What’s the function of nuptial tubercles?

They aid in gripping and sometimes courtship

What are some examples of dermal derivatives?

Connective tissue, cutaneous sense, organs, blood vessels, muscle fibers and membrane bones

Cyclostomata have no scales in ___.

extant forms

Sharks, skates and rays have ___ that are dermal denticles (tooth like)

placoid scales

What clade has denticles on pelvic fins only (chimeras-ratfishes)?

Holocephali

What fossil species has cosmoid scales?

Fossil coelacanth species

What clade has thick ganoid scales with a surface layer of ganoine (bichirs)

Cladista

What clade has sturgeons and paddlefishes that lost scales or have bony plates

Chondrostei

__ (gars) has ganoid scales with ganoine

Holostei

Holostei also has __.

thin flexible cycloid scales

What clade has bony ridge elasmoid scales?

Teleosts

What are the basic scale types?

Placoid, ganoid, cycloid and ctenoid

__ and __ have deciduous scales that easily share

anchovies/herrings

Why is looking at the skeletal system important?

Clues from similar skeletal structures can help us determine taxonomic relationships

What are the two origins of bony fishes

Endoskeletal (endochrondal) bones and dermal bones

Endoskeletal bones are preformed in cartilage in the embryo and then __ ossified.

later

Dermal bones are derived from a membrane and ___ from embryonic connective tissue

are ossified directly

What are the vetebral columns functions?

Protect spinal cord and prevent telescoping of body

What are the two major fish types of vertebrae?

Amphicoelus - bowfins, most teleosts

Opisthocoelous - gars

What are the tail types?

T or F: Chondrocranium = gill arches and jaws

False; thats branchiocranium

What’s the chondrocranium?

brain case

What evolved from arch 1 (anterior gill arches)

Mandibular arch → becomes palatoquadrate and meckel’s cartilage in chondrocranium

What evolved from arch 2 (anterior gill arch)?

Hyoid arch → becomes hyomandibular and ceratohyal in chondrocranium

What becomes the bones in the roof of the mouth and the upper jaw in bony fishes?

The palatoquadrate

__ becomes the articular bone of the lower jaw which connects to the quadrate

Meckel’s cartilage

What becomes the hyal series that supports the tongue?

Ceratohyal bones

About how many bones are in the neurocranium?

40-50 bones

What’s the simple three steps in building the skull?

1. Pectoral girdle attached to the neurocranium

2. Add mix of endochondral and dermal bones'

3. Add last layer of dermal bones

What’s a different evolutionary trend we see in advanced fishes?

Protrusible mouths/jaws

What fishes can open their mouths like humans do?

Extinct ray finned fishes

__ mouths open differently, where their jaw comes out (protrudes)

Advanced teleosts

The anal and dorsal fins aid the muscle in movement for what group?

Pterygiophores

Lepidotrichia is a type of __

fin ray in bony fishes that can be hard or soft (can also be divided into two halves)

What is a bone type that some fish have that can form in the myosepta?

Bowtie or Y bones

What helps fish to breathe?

Ion exchange and gills in contact with the water

What’s the relationship between oxygen levels and factors that impact it?

They are inversely related (an increase in temp would decrease oxygen levels)

T or F: Non-vertebrate chordates are small and relatively active. This allows them to be able to diffuse oxygen into the body

True

___ bring huge surface areas of capillaries into close contact with water

Gills

What’s the gill arrangements of hagfishes and lampreys?

Pouched gills

How many gill slits do all jawed fishes have?

5

How many gill slits do some sharks have?

6 or 7

__ have 4 gill slits covered by a gill cover

Ratfishes

T or F: Sharks, skates, and rays have no external openings per gill slits

False; they have one opening per gill slit to the exterior

How many openings do bony fishes have covered by the opercular flap?

One

What are the two solutions for moving water over gills?

Ram ventilation and buccal pumping

What’s ram ventilation?

A breathing method fish use by allowing water in through the mouth and across the gills by swimming forward

What’s buccal pumping?

A breathing method where fish move water through the mouth and across the gills by their throat muscles

T or F: Blood moves in the opposite direction as water does in fish respiration

True

What’s the psuedobranch?

A structure on the inner operculum in many fishes that is a “false” fin that helps supply more oxygen to the eyes (choroid rete)

__ = site of gas exchange and countercurrent exchange systems are present here

Secondary lamellae

How is surface area increased in fish?

Increase in size and number of the lamellae

What do teleosts have that combat oxygens slow movement in water?

A double pump system with a mouth and opercular pump

T or F: All fish have a double pumping mechanism

False

What happens during the double pump system?

The operculum and mouth can open and close, if the mouth is open the operculum will be closed

What teleosts have lost the double pump ability?

Tunas and some other scrambrids (they have ram ventilation)

Sharks use __ while active and a type of __ while at rest.

ram ventilation/buccal pumping