Morphology and stomach content of the Goldman´s diminutive woodrat Nelsonia goldmani (Cricetidae: Neotominae)

Abstract

Goldman´s diminutive woodrat (Nelsonia goldmani) is an endemic rodent that inhabits the temperate and humid environments of the central highlands of Mexico. This species is considered uncommon because of the scarce and dispersed information about specimens collected across the Faja Volcanica Transmexicana. Therefore, it is crucial to generate new information about the basic biology of N. goldmani, which so much is unknown thus far. We present the morphological description of the stomach and its content from one specimen of N. goldmani. We performed a longitudinal bisection and washing of stomach from one adult male collected at the Natural Park “Las Penas” in the municipality of Jilotepec, Estado de Mexico, Mexico. The macroscopic structures of the stomach were described by observation in a stereoscopic microscope. The stomach content was mounted on sliders and its components were identified and photographed with an optical microscope. According to the gastric glandular epithelium distribution, N. goldmani have a bilocular-discoglandular stomach with a characteristic fornix ventricularis slightly elongated horizontally. The stomach content was composed by several plant items: epidermal tissues of steam and leaves of angiosperms, pollen of gymnosperms, spores of ferns, fungi and animal tissue like mouth appendages and legs of insects. The stomach morphology was similar to the N. neotomodon and the peromyscine Neotomodon alstoni described previously, but the flattened and elongated fornix ventricularis found in N. goldmani was distinctive. Nonetheless, this structure can vary between individuals and mainly depends of the amount of food before dissection. The plant material found in the stomach was similar to that reported in other rodents that inhabit in similar environments to the highlands of central Mexico, such as Peromyscus aztecus, P. difficilis and Reithrodontomys fulvescens.