Fish Flashcards
The cranial skeleton consists of what?
The chondrocranium, the splanchnocranium, the dermatocranium.
What is the chondrocranium?
The ‘box’ that encloses the brain and capsules the sense organs. It protects the brain.
What is the splanchnocranium?
The visceral portion of the skull that supports the gills and contributes to the jaws.
What is the dermatocranium?
The dermal bone that contributes to the braincase and the jaws.
Where is the dermatocranium believed to be derived from?
The external armour of primitive fish.
The splanchnocranium arises _____________ from ___________________.
embryologically from neural crest cells.
Neural crest cells migrate into the wall of the ____________ to form ______________ between the _________.
PHARYNX to form PHARYNGEAL SLITS between the GILLS.
What is the first arch of the splanchnocranium?
The mandibular arch
The mandibular arch is divided into dorsal and ventral sections. Name these sections and describe them.
Dorsal element: palatoquadrate (contributes to the upper jaw)
Ventral element: meckel’s cartilage (contributes to the lower jaw)
What is the second arch of the splanchnocranium called? What is its most prominent component?
The hyoid arch. The most prominent component is the hyomandibula.
Branchial arches I-V are associated with what?
The gill apparatus.
The dermatocranium lies __________ to the chondrocranium.
superficial.
Name the bone series in the dermatocranium.
Facial series Orbital series Temporal series Vault series Palatal series Mandibular series
And the opercular and pectoral series in fish
Name the three bones in the facial series.
Premaxilla, maxilla and nasals.
Name the five bones in the orbital series.
Lacrimal, prefrontal, postfrontal, postorbital, jugal
Name the five bones in the temporal series.
Intertemporal, supratemporal, tabula, squamosal, quadratojugal
Name the three bones in the vault series.
Frontal, parietal, postparietal.
Name the five bones in palatal series.
Vomer, palatine, ectoptergoid, pterygoid, parasphenoid
Name the bones in the mandibular series.
Lateral: angular, surangular, dentary, splenials,
Medial: prearticular, coronoids
What is the name of the whole through which arteries, veins and nerves enter and exit.
Foramen (plural foramina or foramens).
Define autostylic jaw.
Mandibular bone is suspended from the jaw itself without the help from the hyoid arch.
Define amphistylic jaw.
Jaws attached to the braincase in two articulations 1) a ligament connecting the palatoquadrate at the the anterior 2) via the hyomanidbula
Define hyostylic jaw.
Attachment primarily through hyomandibula
Define metautostylic jaw
Jaw attached directly to the braincase via the quadrate at the rear of the palatoquadrate. Hyomandibula gives rise to the stapes.
Define craniostylic jaw.
Entire jaw encorporated into braincase, lower jaw suspended from dermal squamosal. Palatoquadrate/meckel’s cartilage gives rise to incus and malleus.
What are length measurements in fish good for?
1) fisheries: stock assessment, size and growth data
2) species description: distinguishing characteristics
3) investigating intraspecies variation:
4) investigating population or ecological variation
What shape are fish?
Fusiform
Roll
Reduced by fusiform shape and stabilised by dorsal and anal fins
Yaw
Reduced greatly in moving from Anguilliform to Thunniform swimming.
Pitch
Stabilised/reduced by pelvic/pectoral fin
Aspect ratio
= height squared/area
How is dynamic lift generated
generated by propelling a body forward at an inclined angle of attack
How is static lift generated
Generated by using low-density materials and reducing the amount of high-density materials used.
What does the swim bladder do?
Lowers the overall density of the fish.
Most osteichthians have one
Name the primitive and derived swim bladders.
Primitive = physostomous Derived = physoclistous
Describe the physostomous swim bladder.
Pneumatic duct for charging bladder opens into the oesophagus (also via gas gland)
Describe the physoclistous swim bladder.
blood/circulatory system for inflation or deflation
The circulatory system is the source of gases.
How does the physoclistous swim bladder inflate?
Via the rete mirabile
How does the physoclistous swim bladder deflate?
Via oval window by capillary network
Describe the inflation of the physoclistous swim bladder
Gas gland releases lactic acid in rete mirabile, which acts as a countercurrent multiplier.
Describe the deflation of the physoclistous swim bladder
Bladder walls have low permeability so when sphincter relaxes, the pressure forces oxygen into oval window and bloodstream
Name four ways to increase buoyancy
1) reduce the number of heavy tissues
2) Use low-density compounds
3) Generate lift as a product of swimming
4) The evolution of a swim bladder
In what period did jaws develop?
The Silurian
What type of fishes first developed jaws?
Placoderms
What did jaws arise from?
The two most anterior pairs of gill arches
_____________ of sharks show that ____________ and jaws develop similarly ___________
Embryology of sharks show that jaws and branchial arches develop similarly in series
_____ and _______ of branchial arches and jaws are distributed in a similar pattern
nerves and blood vessels
Musculature of the jaws appears to be __________ and ___________ from ____________ musculature
Musculature of the jaws appears to be transformed and modified from branchial arch musculature
What happened as a result of the evolution of the jaw?
1) They could grasp objects firmly (extended phenotype)
2) They could eat things bigger than themselves
3) The evolution of the immune system potentially (Matsunaga and Rahman, 1998).
