Exotics - Fish 1

pbhati17's version from 2017-03-08 14:14


Question Answer
What can fish regenerate like a boss?CNS
Do fish scar?No!
*Fish tumors normally don’t metastasize. What is the exception? What type of fish?Aflatoxin - induced hepatic carcinomas in trout
*What type of virus czs Carp Pox?Trick question: Herpes!
Should the skin of fish have a nice mucous layer? What might cz excess mucus?Yes. Excess mucus = parasitic dzs or water quality problems
Which 3 parts of the fish are covered by a mucosal surface?Skin
*What increases the surface area of the gills? What is this covered by? How does this help?Gills have microridges to ↑ surface area. Mucus covering helps smooth water flow over the gills
If a fish is sick, will it be darker or lighter than normal?Darker
What are the 5 layers of skin starting from the outside?(1) Cuticle
(2) Epidermis
(3) Dermis
(4) Hypodermis
(5) Subcutaneous muscle
Which skin layer is covered w/ mucus? What are the 2 main fxns of this mucopolysaccharide layer?Cuticle = covered w/ mucus layer
Main fxns of the skin?(1) Immunoprotective
(2) Helps reduce turbulence during swimming bc skin is ridged - that whole scale thing
Which layer of the skin varies in thickness btwn spp, w/ age/site on body/stage of reproductive cycle?Epidermis
What are 2 times the epidermis gets thicker?(1) If it's a fish w/ no scales
(2) Stage of reproductive cycle
What is the difference btwn the epidermis of mammals & fish?Mammals: outer layer of skin is dead/keratinized
Fish: capable of mitotic activity at outermost level, ie all cells alive
What are scales made out of? Why might they be resorbed & by what cells?Bone, therefore can be resorbed by osteoclasts during periods of ↑ Ca2+ demand
*What layer of the skin are scales embedded in? Do all fish have scales? Do scaly fish have scales everywhere?Superficial dermis
No, some fish don’t have scales (ie catfish). Scaly fish lack scales on top of head/fins
Scales along this line have a pore, allowing sensory cells access to outside water. Where does this connect to on the head?Lateral line, join supra & infra-optic sensory canals
**Which cells of the epidermis produce mucus?Goblet cells
**Which cells of the epidermis produced by schooling-fish produce a substance that scares away predators?Club cells
aka fright cells
aka Shreckstoffzellen
What pigments are responsible for white/silver colors of fish? What nucleic acid do they contain?Leukophores, contain guanine
What are plates of reflecting material arranged in parallel rays like a venetian blind?Iridophores
What gives black, red & yellow pigment?Black: Melanophores
Red: Erythrophores
Yellow: Xanthophores
What are the results of sloughing of epidermis in fresh water? Salt water?Fresh water: Water-logging
Salt water: Dessication
What is the consequence of edema on the scales?Often leads to deconstruction & resorption of the scales by osteoclasts
How much of the gill do you have to loose before you start to see CS?>50%
*What are some general responses of gill cells to injury?Cell swelling
Lamellar tip fusion
*Where might you look in the gills for eosinophilic granular cells indicating inflammation?Central venous sinus
*What organism can lodge in the gills czing dmg?Chaetoceros, a diatom (algae)
**This is nonspecific hyperplasia that occurs in the gills in response to irritation. What organism is commonly associated?Called “clubbing”, Cochiopodium (amoeba) commonly associated
**Which yellow pigmented filamentous bacteria, common in fresh & salt water, czs minimal pathological change but massive mortality & czs yellow pigmentation of the skin?Flavobacterium branchiophilum
**What is the pathogenesis of Flavobacterium infxn?Fish die from prostaglandin-mediated severe vasoconstriction, 30 min after bacteria are introduced the blood gas levels crashed (NSAIDS can reverse if you act quickly)
What gives gills the majority of their color? Why might they be pale?Gills: color from blood, pale bc of anemia/vascular shutdown
*Which part of the gill receives its O2 directly from the water? Why is smooth flow here so important?Gill lamellar epithelium, smooth/efficient laminar flow crucial bc it allows exchange w/ countercurrent blood flow
*In warm/polluted waters, energy required to extract O2 from the water can exceed that released by obtained O2. What is the name of this problem?Respiratory Distress Syndrome
What are the 2 pumps that allow this smooth laminar flow of water over the gills?(1) Buccal pump
(2) Opercular pump
**Besides respiration, what are the other 3 crucial fxns of the gills?(1) Osmoregulation
(2) Acid-Base balance via Na/NH4, Na/H, Cl/HCO3 exchangers
(3) Excretion of Nitrogenous waste materials
You see fish crowding at water inlets on your fish farm. What is probably wrong?↓ O2 levels
You see foaming of the water in your tank, what should you check for? Why?Foaming = indicator of mucus production bc of irritation
Check for bacteria/parasites
How many pairs of gill arches do fish have? What is the gill arch covered by? Each arch has how many rows of filaments? What do the filaments support? What is the true respiratory tissue?Fish have 4 gill arches covered by epithelium
Each arch supports 2 rows of filaments
Filaments support the lamellae which are the true respiratory tissue
*What ↑ surface area on the surface of epithelial cells? What happens if these cells are covered w/ mucus?Epithelial cells = microridges to ↑ surface area. Filling in of these ridges → smooth surface, therefore reducing turbulence/energy expenditure
Term for fish that respond to environmental hypoxia by ↑ water flow over the gills?O2 regulators
What is an acute response of the gills to euthanasia/rough handling?Lamellar aneurysm
**What are 2 chronic responses to injury? What is the consequence?Hyperplasia & fusion “clubbing” → impaired O2 uptake/CO2 excretion
What is branchitis?Inflammation of the gills


Question Answer
What are the effects of eosinophilic granular cells on respiration? What are they in response to?Eosinophils: response to chronic, esp. parasitic dz impair respiration
*When fish die acutely bc of gill problems, what are the 2 main effects?(1) O2 drop
(2) Vasoconstriction
*What is the major hematopoeitic organ?The kidney!
Which organ is responsible for helping freshwater fish fight over-hydration & salt-water fish from under-hydration?The kidney!
What is in the anterior portion of the kidney? The posterior?Anterior: Lymphoid tissue
Posterior: Lympohoid, hematopoeitic & nephrons
What are the sinusoids of the anterior kidney & peritubular capillaries of the portal system lined w/?Renal portal macrophages, Highly phagocytic
*Where is a good place to look for antigens (ie bacteria?)Renal portal macrophages!
*What are the 2 most important organs for trapping/filtering debris in the blood as well as the 2 organs you should you sample 1st when looking for dz?The kidney (vs. the liver in mammals), then the spleen!
**What system drains the tail area? What is it lined by?Renal portal system, lined by macrophages
*Do fish have a hepatic portal system? What is it not lined by?Yes have hepatic portal system, not lined by macrophages (but the renal portal system is!)
**Which 2 organs have the highest levels of CYP450?Liver, Heart
*How does blood flow in the fish?(Starting w/ venous return) Venous blood from the body → sinus venosus → atrium → ventricle → bulbus arteriosis
*What type of tissue is the atrium? What is it lined by?Spongy, thin, lined by endocardium
*What are the endocardial cells able to do in terms of innate immunity?Endocardial cells are highly phagocytic
*What are the 2 layers of the ventricle? What are the metabolic differences?(1) Compact layer: Aerobic, supplied w/ coronary vessels
(2) Spongy layer: Glycolytic, no coronary vessels
*What layer is best-developed in fast-swimming fish & may be absent in slow-moving fish?Fast-swimming fish: more developed compact layer
***How do you calculate cardiac output? What part of the equation is more important in fish? Therefore, what type of lesion has a more severe affect? What is 1 example of this type of lesion?CO = SV X HR
Fish rely more on stroke volume, so constrictive lesions have a more severe affect
Example: Fibrinous pericarditis
What is the only lymph-node like organ in teleosts?The spleen
What are ellipsoids?Splenic capillaries
*What are the “trashcans” of the spleen, for dead cell products/pathogens eliminated by macrophages?Melano-macrophage centers (MMC)
Does a fish liver have Kupffer cells?Nope, that’s why the kidney/spleen have to remove pathogens
The liver may be discrete or compound - what organ is it combined w/?Hepatopancreas (Cyprinids)
What do some spp store in the liver, making it appear lighter in color?Lipids
Compared to mammals, is the intraocular pressure in fish ↑ or ↓? Why?Intraocular pressure in fish is ↓ bc cornea has no need to be smooth optically
Do fish have eyelids? Do they see in color?No eyelids!
Yes, they do see in color!
*What are 2 common eye problems in fish, what czs them?(1) Cataracts: Nutritional, Parasitic
(2) Eye fluke
W/ a fixed lens & pupil, how do fish focus?Move lens around w/ retractor lentis m.
*How do fish limit the amount of light hitting the retina?Encasing photoreceptors in melanin from the retinal pigmented epithelium (RPE)
How long does encasing photoreceptors in melanin from the retinal pigmented epithelium (RPE) take? Can a fish adapt immediately if you flick on the lights?Takes about 30 minutes, so a fish will have its eyes hurt if you flick on the lights
What is the purpose of the choroidal rete? What can be trapped here?Supplying O2 to the retina, involved in retinal dehydration. Microbial or gas emboli can be trapped here
What is the falciform process?Part of the choroid layer of the eye which is enlarged and filled with blood vessels, It carries nutrients to posterior compartment of the eye, & is source of inflammatory cells

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