Djungarian Hamster Flashcards
Genus, species, and common name of Djungarian hamsters.
Phodopus campbelli, Russian dwarf
Phodopus sungorus, Siberian dwarf
What characteristic differentiates the Djungarian hamsters?
P. sungorus molts to pure white haircoat in response to short photoperiod, P. campbelli retains gray haircoat.
Where are the Djungarian hamsters found in the wild?
Russian dwarf - Siberia, China, and Mongolia. Distant relative of Syrian.
Siberian dwarf - Steppes of Kazakhstan, Manchuria, and northern China
What size are Djungarian hamsters?
18-25g, with mature males reaching 40-50g.
How long do Djungarian hamsters live?
9-15 months, although survival up to 2 years reported.
What is the diploid chromosome number?
2n = 28
What are Djungarian hamsters susceptible to?
High incidence of neoplasia. Susceptible to carcinogens. Can be infected with oncogenic viruses, particularly Rous sarcoma vrius, human mastadenovrius, and SV40.
What are Djungarian hamsters used for today?
Behavior and reproductive physiology studies.
What is unique about the repro cycle of Djungarian hamsters?
Most compressed repro cycle of any eutherian mammal. Can mate on the day of parturition (following 18 day gestation) and deliver the second litter, while weaning the first, within a 36 day time period.
Describe the estrous cycle of Djungarian hamsters.
4-day estrous cycle with spontaneous ovulation.
What is pregnancy in P. campbelli dependent on? Describe prolactin in this species.
Progesterone from CL through late gestation. Prolactin is late or absent mid-gestation and resumes in late gestation. Roles for reappearance may be influence on lactation, mammary gland development, and regulation of maternal behavior towards newborns.
Describe paternal care in both species of Djungarian hamster.
P. campbelli - Depends on monogamous parental care by both parents.
P. sungorus - Male does not participate in rearing.
Describe the personality of Djungarian hamsters and how it impacts breeding.
Nonaggressive females can be maintained in breeding pairs throughout life.
How many litters can a female Djungarian produce in her reproductive years?
Between 1-18 litters, with 1-9 pups/litter.
How does exposure to a male impact reproductive development in females?
Accelerated.
What behavioral adaption is present in P. sungorus during pregnancy?
Food hoarding to provide accessible energy.
As adults, Djungarian hamsters are dependent on the critical photoperiod of what? What does a change in photoperiod induce?
13h, compared to 12.5 in Syrian and 15.5 in European. Change in photoperiod influences seasonal changes in breeding activities, thermoregulation, hair-coat growth, and fat metabolism.
What are Djungarian hamsters used for in research?
Studies of pineal gland and melatonin secretion in mediating the effects of photoperiod.
Do Djungarian hamsters hibernate? How do they adapt to colder temperatures?
No, even when exposed to temps below -40C. Seasonal acclimation of blood-gas transport facilitated by increased relative heart weight, increased surface area of erythrocytes, and slightly altered hemoglobin content, which all aid oxygen transport. Also decrease resting metabolic rate and increase capacity for nonshivering thermogenesis.
Describe the diet of Djungarian hamsters.
Omnivorous. Maintained on same diet of Syrians for cheaper, due to smaller size.
Djungarians develop a high incidence of neoplasia in what sex and locations? How has this changed with time?
Females. Oral cavity, skin, and mammary glands. Mammary tumors increasing and skin tumors decreasing in frequency, may be due to inbreeding.
What clinical signs are seen in dwarf hamsters with neoplasia?
Rapid weight loss, similar to that seen with bronchopneumonia or incisor malocclusion.
Female Russian dwarf hamsters prevented from breeding can develop what condition?
Cystic ovaries, with swollen abdomens and bloody vaginal discharge.
European hamsters may be hypersensitive to what bedding material?
Cedar chips, with alopecia, dry skin, and secondary bacterial infections.
Dwarf hamsters do not develop what common condition in other hamsters?
Enteritis with rectal prolapse.
