Phodopus

Phodopus[1] Temporal range: Pleistocene to Recent
Roborovski hamster (Phodopus roborovskii)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Cricetidae
Subfamily:	Cricetinae
Genus:	Phodopus Miller, 1910
Type species
Cricetulus bedfordiae Thomas, 1908
Species
Phodopus campbelli Phodopus roborovskii Phodopus sungorus

Phodopus is a genus of rodent in the vole and hamster family Cricetidae. Its species, together with those of genus Cricetulus, are known as "dwarf hamsters", because of their small size. They are common as pets in Europe and North America. They are less popular than Syrian hamsters as pets, but smaller and more sociable.

There are three species of Phodopus: the Djungarian hamster, the Campbell's dwarf hamster and the Roborovski hamster. They inhabit the forests, steppes and semi-deserts of Mongolia, Siberia, China and Kazakhstan. They have a short tail, from 4 to 13 millimetres (0.16–0.51 in) in length, depending on the species.

Some species, such as the Djungarian hamster, have special features to cope with extreme temperatures, such as furry paws and thermoregulation. Both in the wild and in captivity, Phodopus live from 1 to 3.5 years of age, depending on species, diet and lifestyle.

Species

There are three main species of Phodopus: the Campbell's dwarf hamster (P. campbelli), the Roborovski hamster (P. roborovskii) and the Djungarian hamster (P. sungorus).^[1] They are more limited in colour than the Syrian hamster, but smaller and more sociable.^[2] If exercised and handled often, they can become friendly and used to humans.^[3] The Campbell's dwarf hamster and Djungarian hamster can reach 1–2 years of age,^[2] and 8–10 centimetres (3.1–3.9 in) in length.^[3] Due to their similar size and colour, these two are often mistaken for a single species.^[4] The Roborovski hamster is the smallest Phodopus species; it can reach 4–5 cm (1.6–2.0 in) and 3–3.5 years of age.^[2] All Phodopus species have tails approximately 4 millimetres (0.16 in) long.^[5] The Djungarian hamster is capable of thermoregulation and has furry paws, enabling it to cope with extreme temperatures.^[4] In the wild, Phodopus are hunted by owls, foxes, weasels and ferrets.^[2] However, as they reproduce quickly, hunting does not threaten the species' survival.^[5]

Biology

The body length of Phodopus hamsters ranges from 5.3–10.2 cm (2.1–4.0 in) and the length of the tail from 4–14 mm (0.16–0.55 in).^[6] The eyes are small relative to the rest of the body.^[7] The paws are short and broad. The first toe of the front paw has a blunt claw, while the remaining toes have sharper claws.^[3] The soles of the feet are hairy, keeping them warm in extreme temperatures.^[7] The fur ranges from brown to yellow, with white paws.^[4] The sides of the nose, upper lip, the lower part of the cheeks and flanks, the limbs, tail and stomach are almost always white.^[6] The neck is relatively weak and short. The ears are thin and hairy.^[3] Females have eight teats.^[2]

Skeleton

A Phodopus pelvis is similar to that of a mouse, with a short ilium and weakly pronounced iliac tubercle. The femur is short – only slightly longer than that of a mouse. The tibia is adjacent to the fibula and is comparatively^{[clarification needed ("comparatively" to what?)]} long. The humerus is not shortened. The ulna is long, with a short elbow extension and a wide and shallow groove along the outer surface.^[2]

Skull

The Phodopus skull is relatively^{[clarification needed (relative to what?)]} small, compared to the rest of the body. The source area of the masseter muscle on upper jaw is well defined, covering the infraorbital canal and extending further than in other hamsters, upward and back to the front portion of the zygomatic arch.^[2]

The brain is high and extended. There are no bone strips between the frontal and parietal bones. The auditory bullae are similar to those of mice: small and tubular with extended front ends.^[5]

The small lower jaw is a common characteristic of Phodopus. The supporting bone of the teeth protuberance is poorly developed and is in the middle of the muscle extension. The mandibular body is short and steeply curved compared with that of other rodents.^{[5][page needed]}

Teeth

The cusps of the upper molars are located opposite each other. Even if they are slightly offset against each other, the groove in between them is closed. Only the groove between the middle pair of the first molar cusps may be open as visible from the front. In the lower molars, the cusps are offset from each other.^{[4][page needed]}

Breeding

Unlike Syrian hamsters, Phodopus do well when paired at a young age and allowed to mature together.^[8] Once pregnancy is visible, birth can be expected in 2–7 days.^[2]

History

G.T.Miller first described the genus Phodopus in 1910, designating Cricetulus bedfordiae as its type species.^[1] (C. bedfordiae is the species now called P. roborovskii.)^[9] The genus name derives from ancient Greek phodos (φωδος, genitive of phos φως "blister") and pous (πους "foot") and refers to the large pad on the sole of each foot.^[9]:p.6 Before being domesticated, Phodopus were pests on grain crops and carried many pathogens which caused contagious diseases in people.^[10]

Diet

In the wild, dwarf hamsters eat a variety of seeds and insects such as crickets and mealworms. They also eat the seeds of plants such as peas.^[11]

In captivity they can eat a variety of commercially available pelleted hamster foods, as well as fruits and vegetables such as carrots. However, fruits that are high in sugar, such as grapes, can lead to kidney failure, tooth decay and even death.^[11]

Habitats

Phodopus species inhabit the mountainous and flat forests, steppes and semi-deserts of Mongolia, and the adjacent areas of China, northeast Kazakhstan and the southern part of the West Siberian lowlands of Tuva and Dauria.^[12] All three species are abundant and are assessed as Least Concern in the IUCN Red List.^[13][14][15]

Phodopus fossils have been found in Northen Europe, the Middle East and Asia.^[12] Miller classified Phodopus as Cricetulus, after discovering more fossils in the caves of Somerset, England, and in other parts of Europe.^[16]

References

1. ^ ^{a b c} Musser, Guy G.; Carleton, Michael D. (16 November 2005). "Genus Phodopus". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). pp. 1045–6. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=13000368. 
2. ^ ^{a b c d e f g h} Mays, Marianne (1 February 2000). How to Care for Your Dwarf Hamster. (Your first...series). Havant: Kingdom Books. ISBN 1852791500. 
3. ^ ^{a b c d} Honigs, Sandra (2005) (in German). Zwerghamster: Biologie, Haltung, Zucht (2nd ed.). Münster: Natur und Tier-Verlag. pp. 9, 56–58. ISBN 3-931587-96-7. 
4. ^ ^{a b c d} Krylzow und Schubin 1964. Zitiert in: Ross 1998 (S. 1, „General Characters“).
5. ^ ^{a b c d} Lynn Vanderlip, Sharon (2009). "Dwarf hamsters: everything about purchase, care, nutrition, and behavior" (in English). Barron's. p. 35-37, 49, 57, 63-69, 72-81. http://books.google.co.uk/books?id=Y2b8D6t658gC&printsec=frontcover&dq=Dwarf+Hamsters:+Everything+about+Purchase,+Care,+Nutrition,+and+Behavior&hl=en&ei=pGUxTrrMIJGfmQXNuIDfCQ&sa=X&oi=book_result&ct=result&redir_esc=y#v=onepage&q&f=false. Retrieved 31 October 2011. 
6. ^ ^{a b} M. Nowak, Ronald (1999). Walker’s Mammals of the World (6th ed.). Johns Hopkins University Press. ISBN 0-8018-5789-9. 
7. ^ ^{a b} The Dwarf Hamster: A Guide to Selection, Housing, Care, Nutrition, Behaviour, Health, Breeding, Species and Colours. Kingdom Books, Blackrock. 2003. ISBN 9781852792107. 
8. ^ Ken Brocx. "Dwarf Hamster Breeding". Hamsterific.com. http://www.hamsterific.com/breedingdwarfs.cfm. Retrieved 2011-07-29. 
9. ^ ^{a b} Ross, Patricia D. (2 June 1994). "Phodopus roborovskii". Mammalian Species (The American Society of Mammalogists) (459). http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-459-01-0001.pdf. Retrieved 28 October 2011. 
10. ^ Piechocki, Rudolf (1969). Familie Wühler. Enzyklopädie des Tierreichs. pp. 301-344. 
11. ^ ^{a b} Grzimek, Bernhard (in English). Go to Google Books Home Advanced Book Search Grzimek's Animal Life Encyclopedia: Mammals I-IV (12 ed.). Van Nostrand Reinhold Co.. http://books.google.co.uk/books?id=QLJ2DwEACAAJ&dq=Grzimek%27s+Animal+Life+Encyclopedia&hl=en&ei=Xw6vTqDqDtDtsgakgMFE&sa=X&oi=book_result&ct=result&resnum=7&ved=0CE8Q6AEwBjgK. Retrieved 31 October 2011. 
12. ^ ^{a b} McKenna, Malcolm C. (1997). Classification of Mammals Above the Species Level. Columbia University Press. pp. 150, 631. ISBN 0-231-11012-X. 
13. ^ Tsytsulina, K. (2008). "Phodopus sungorus". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/17037/0. Retrieved 20 August 2011. 
14. ^ Shar, S. & Lkhagvasuren, D. (2008). "Phodopus campbelli". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/17035/0. Retrieved 20 August 2011. 
15. ^ Shar, S. & Lkhagvasuren, D. (2008). "Phodopus roborovskii". IUCN Red List of Threatened Species. Version 2011.1. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/17036/0. Retrieved 20 August 2011. 
16. ^ Schaub, Samuel (1930). Quartäre und Jungtertiäre Hamster. Abhandlungen der Schweizerischen Paläontologischen Gesellschaft. pp. 1–49. 

External links

• My Roborovski Hamster – Site that is dedicated to helping Roborovski Hamster owners.
• Pet Web Site (formerly The Complete Hamster Site) section on Hamsters
• Russian Dwarf Hamsters information from breeder Jean McGuire
• http://www.dwarfhamstercare101.com/campbells-dwarf-hamster/