Order: Rodentia. Family: Muridae. Commonly known as: African soft-furred rat, Natal rat, Multi-mammate Rat, Multi-mammate Mouse. Also known as: Praomys natalensis, Mastomyshildebrandtii (Hildebrandt's Multimammate Mouse). Native habitat is South Africa. Virtually indestinguishable from M. coucha without recourse to cytogenic analysis. Wild phenotype is medium agouti with no markings.
Phenotypes:
Medium self agouti (wild phenotype)
Pied medium agouti (seems to be most common USA phenotype).
Pied dark agouti (in front with medium agouti for comparison):
From "Uncommonly Used Laboratory Animals " http://netvet.wustl.edu/species/exotic/uncomsp.txt
Family: Muridae Mastomys (Praomys) natalensis Multimammate Rat South Africa y & z strains; 40-80 gms; intermediate between rats and mice; may bite even unprovoked; G 23 D; LS 6-8; estrous 7-8 D; monogamous pairs; well developed prostate in female; os penis- male; 8-10 pair mammae; no gall bladder; Diseases: LASSA FEVER- Zoonotic. Research Uses: Most susceptible rodent to osteoarthritis; Carcinoid tumors- argyrophilic, histamine producing tumors of the gastric mucosa, distal metastasis, transplantable & spontaneous; 185-Antral adenocarcinoma- spontaneous in y & z strains, only animal model in humans; Induced gastric ulcer- injections of ovalbumin into mucosa of stomach of previously sensitized animal; plague (very susceptible); Bilharziasis (Schistoma); 220- Lassa fever (arenavirus) only nonhuman host; toxoplasmosis; chronic renal disease with glomerulonephritis; thymomas & hematopoietic neoplasms; polymyositis; epithelial skin, pancreatic, glandular gastric & prostate tumors; female prostate hormonal effects; congenital erythrocyte porphyria; aging; autoimmune disease
Simmers, M. H., Ibsen, Kenneth H., and Berk, J. Edward. 1968. Concerning the Incidence of "Spontaneous" Stomach Cancer in Praomys (Mastomys) natalensis. Cancer Research 28, 1573-1576.
Husbandry excerpts from above papers:
JACKSON, T.P. & VAN AARDE, R.J. 2004. Diet quality differentially affects the breeding effort of Mastomys coucha and M. natalensis females: implications for rodent pests. Journal of Experimental Zoology Part A: Comparative Experimental Biology 301A: 97–108. "Only M. natalensis females bred on 6% protein diets, while on 20% protein
diets the reproductive output of M. coucha was lower than on diets containing 10– and 15%
protein. M. natalensis responded to low protein diets by reducing litter size and litter mass but
not individual pup mass. Thus, providing diet quality improves before parturition, conception under
sub-optimal conditions may not compromise individual pup growth."
JACKSON, T.P. & VAN AARDE, R.J. 2004. Diet quality differentially affects the breeding effort of Mastomys coucha and M. natalensis females: implications for rodent pests. Journal of Experimental Zoology Part A: Comparative Experimental Biology 301A: 97–108. "Commercial mouse pellets ... and water were provided ad libitum. In addition animals were provided with fresh sawdust bedding and plastic shelters. ... Litters produced by these wild-caught pairs were removed at weaning age ... and fed mouse pellets ad libitum until 50 days old... then randomly paired (not with siblings) and assigned to one of four treatment groups (6, 10, 15, or 20% protien diets).... The experimental diets ... were designed so that all nutritional components, except digestible protein content, which varied according to treatment level, remained constant...."
LAMB, C.E. & VAN AARDE, R.J. 2001. Maternal dietary intake and sex-specific investment in Mastomys coucha (Rodentia: Muridae). Journal of Zoology, London. 253: 505–512. "Abstract: We examined data on captive multi-mammate mice (Mastomys coucha) to assess differential maternal investment, and sex-specific resource allocation. Differences in maternal size were induced through manipulation of dietary protein in three treatment groups: low (10%), medium (15%) and high (20%) protein diets. Mothers on the 20% protein diet were significantly larger than those on the lower protein diets, and produced significantly more male than female offspring. Mothers on the lower protein diets did not produce sex-biased litters. There were no sex-specific differences in body size or body tissue composition of pups at birth or at weaning within each treatment group. At weaning, pups in the 20% protein treatment group had proportionately greater amounts of lean tissue and less body lipid reserves than pups in the 10% protein treatment group. Pups in the 20% protein treatment group were also larger, and had faster growth rates, than those in the 10% protein treatment group. Weaned pups in the 15% protein treatment group had the fastest growth rates and greatest energetic reserves of all of the treatment groups. Our results suggest that larger mothers on the high (20%) protein diet show differential investment in the sexes, not by allocating more resources to individuals of that sex, but by producing more male than female offspring."
Hallett, A. F., 1977. Evaluation of Live Attenuated Plague Vaccines in Praomys (Mastomys) natalensis, Infection and Immunity, Vol 18, pp 8-9. "The Praomys (Mastomys) natalensis colony was built up from animals caught in Johannesburg in 1946 and maintained at the South African Institute for Medical Research since that time. The animals are about twice the size of a white mouse, the body weight at maturity being between 50 to 70 g. For experimental work, they were used when they were 9 to 12 weeks old at a body weight of 25 to 30 g. Food consisted of standard mouse cubes supplemented with carrots, potatoes, and cabbage once a week. Water was supplied by a drop bottle. Animals under experient were caged singly in cages 13 by 13 by 18 cm. Care had to be taken in handling Praomys as they are agile and bite viciously."
Simmers, M. H., Ibsen, Kenneth H., and Berk, J. Edward. 1968. Concerning the Incidence of "Spontaneous" Stomach Cancer in Praomys (Mastomys) natalensis. Cancer Research 28, 1573-1576. "The animals were housed in plastic cages and fed Purina Laboratory Chow for rats and mice ad linitum. Tap water was continually available. Breeding females were give a supplement of sunflower seed, which appeared to reduce cannibalism of the newborn."
Thanks to Prof R. J. Van Aarde and Tim Jackson for the links to their articles.
Copyleft notice: Believe it or not, this page is mostly not copyrightable, being simply a collection of facts, except for the photographs, which I took myself. (Copyright for the scientific articles belong to their respective authors and are quoted under fair use.) Even so, the contents of this page represent hours of work and I'd appreciate a credit if you choose to use it rather than search out all this stuff on your own. Thanks! --batwrangler at gmail dot com.
