Midterm Review Flashcards
Name one important event that occurs at Metaphase 2 in the development of fish eggs?
Fertilization..
At which stage does meiosis stop to allow vitellogenesis to proceed?
Prophase 1
At Prophase 2 in the development of fish eggs the nuclear membrane of the egg disappears for a second time. What name is given to this event in the fish reproductive biology?
GVBD
When androgenesis is applied to fish in which males have heterozygous sex chromosones( XY) what is the sex chromosome composition of the resulting fry and what are the proportions of the resulting groups?
1/2 female XX
1/2 male YY
Thecal and granulosa cells form the wall of which feature of the fish ovary?
Follicle
In developing a triploid stock of fish, using shocking techniques, the timing of what critical stage of meiosis is determined?
Anaphase 2
What effect does estrogen have on the liver during fish gonad recrudescence?
Stimulates vitelligenin and lipid production in the liver
List 3 methods to remove eggs from maturing female fish to examine their stage of development?
- Hand stripping
- Surgically remove and suture
- Sacrifice and cut open
Or use the tube to suck eggs out
How would you identify the ovary of a fish displaying synchronous oogenesis?
oocyte at one stage of development
What hypothalamic hormone inhibits the secretion of gonadotropic hormone by a fish pituitary?
GTHRHIF- dopamine
Name a chemical that can be used to decrease or eliminate the negative feedback that estrogen has on a pituitary secretion of gonadotropic hormone?
Tamoxafin
What is the main environmental cueing mechanism which inhibits recrudescence in mature temperate freshwater and marine fish?
photoperiod
Why have tropical freshwater fish evolved to use changes in water quality as an important cur for ovulation?
Increase in nutrients and increase in productivity due to the rainy season
What hormone serves as a photoperiod transducer in the reproductive biology of fish?
melatonin
What two characteristics of photoperiod are most important in cueing recrudescence in fishes?
- direction of change
2. rate of change
List 2 reasons why LHRHa is the most likely reproductive hormone to succeed in inducing ovulation in difficult to spawn fish?
- It is not species specific
2. It stimulates the fishes own GTH to increase
Doperidone blocks the action of what hormone in fish reproduction, aiding ovulation?
Blocks dopamine
Name 2 substrates that can be used to make pellets for the long term administration of spawning induction hormones in fish?
- Coconut oil
2. Cellulose
What human hormone can be used to stimulate or mimic the gonadotropins of fish when inducing fish to spawn?
HCG
List 3 disadvantages of the use of sex steroids in producing MONOSEX stocks of fish?
- Low market appeal
- Must treat all production fry
- fry must be obtained less than days from hatch
What advantage does gynogenesis offer in developing lines of monosex female fish for masculinization with testosterone?
You will know all fry are female
Balon’s reproductive fish guilds are based on what 3 characteristics of fish reproduction?
- early development form and function
- preferred spawning ground and substrate
- adult reproductive behavior(spawning and incubation)
IN pelagic marine fish, which scatter eggs, what component of the egg determines the depth at which it incubates?
Lipid content
What purpose might a downwardly curved tail, in a fish larvae, serve?
forces the larvae to swim down to hide
Larval fish use highly vascularized fin folds and yolk sacs to serve what function in their physiology?
auxiliary respiratory feature
What differentiates an ovi-ovoviviparous fish from a vivipariorous fish?
ovi-ovo- eggs deposited, nutrition from yolk
vivp- fry released, nutrition from mothers blood
Which two genera of the tribe Tipapini feed largely on phytoplankton?
Oreochromis and Sartherodon
Describe the arena spawning in the subfamily Tilapini?
- Male builds nest, attracts female, female puts in mouth and female leaves
what 2 morphological features of the digestive system would identify a fish as carnivorous and adapted to eat large meals of easily digested protein infrequently\?
- large stomach
2. small intestine
Give the common name of 3 of the most important members of the subfamily Tilapiini in commercial aquaculture?
- Nile Tilapia
- Egyptian
- Hornorum
- Blue
List 4 means of achieving monosex male stocks when commercially rearing tilapia?
- hormonal sex reversal
- high temperature incubation
- hybrids
- manual sexing
How do the urogenital papillae of male and female Oreochromis differ?
female- 2 openings
male- 1 opening
What does the term HAPA refer to in fish culture?
Asia cages for Tilapia reproduction control
What chemical, used to masculinize tilapia has been banned for this purpose in Canada and the United states?
Methyl testosterone
Shock is used to produce mitotic and meiotic gynogens. What cellular process is stopped in each case?
Mitotic- 1st cleavage
Meiotic- loss of 2nd polar body
when a hormonally induced heterozygous (XY) female is spawned with a regular heterozygous male fish, the fry contain both the XY male and YY super male fish. How can the YY males be identified?
progeny testing
If homozygous female tetraploid fish (XXXX) are bred with hormonally masculinized homozygous male fish (XX) what is the sex and the sec chromosome compliment of the fry?
FEMALE
XXX- triploid
