(Download) "Effect of Litter Size on Performance of a Motor Task in Three Species of Pocket Mice (Heteromyidae: Chaetodipus)." by The Texas Journal of Science # Book PDF Kindle ePub Free
eBook details
- Title: Effect of Litter Size on Performance of a Motor Task in Three Species of Pocket Mice (Heteromyidae: Chaetodipus).
- Author : The Texas Journal of Science
- Release Date : January 01, 2003
- Genre: Engineering,Books,Professional & Technical,
- Pages : * pages
- Size : 191 KB
Description
Abstract.--Effects of litter size and sex on performance of a motor task were examined in three species of pocket mice (Chaetodipus penicillatus, C. nelsoni and C. intermedius) at two levels of difficulty. Neonatal mice were weaned in small (n = 2) and large n = 5) litter sizes. There was no significant interspecies difference in mean weight of neonatal mice. However, at 40 days of age, mice from all species reared in smaller litters exhibited significantly higher body weights than their counterparts from large litters. The motor task required 40 day old mice to traverse a metal rod to move from one elevated platform to another. The difficulty of the task was attained by using a thicker (low difficulty) and thinner (high difficulty) rod. Animals that were able to traverse the rod without falling off received a score of 1; those falling off received a score of 0. Because mice received two trials/day for five days, performance scores could range from 0 to 10 for each level of difficulty. There was no significant difference in motor performance as a function of sex or species in any experiments. All mice exhibited higher performance scores when traversing the thick rod (8.9 to 9.4) as compared to the thin rod. With the thin rod, all animals from smaller litters showed significantly higher performance scores (5.7 to 6.1) than those from large litters (2.3 to 3.1). Thus, ability to perform a specific motor task is influenced by litter size in these pocket mice. **********