Rocky Mountain Research Station Publications

RMRS Online Publication - Journal Articles, External Publications, and Special Reports
Feeding preference of the Rio Grande silvery minnow (Hybognathus amarus)


Magana, Hugo A. 2009. Feeding preference of the Rio Grande silvery minnow (Hybognathus amarus). Reviews in Fisheries Science. 17(4): 468-477.

The Rio Grande silvery minnow (Hybognathus amarus) was historically the most abundant fish in the Rio Grande Basin. However, populations have been declining to the point of being listed under the Endangered Species Act. Potential causes for the decline have been studied, yet little attention has been paid to food resources. This study had three objectives: (1) Determine whether larval fish show a substrate preference when foraging. (2) Determine whether larval fish have a diatom preference when presented with 15 diatom species over six feeding trials. (3) I investigated the possibility of training/conditioning H. amarus to feed on natural food sources (diatoms) and observe conditioning response (reaction time to feeding). I found no difference between substrate preference (p = 0.26). Results for feeding trials 1, 2, and 3 revealed a preference for Nitzschia palea (p < 0.01). Trial 4 revealed a preference for N. paleaformis (p < 0.01). Navicula veneta was the preferred diatom species in feeding trial 5. Nitzschia cf. intermedia was preferred in trial 6 (p < 0.03). Results from these feeding trials proved that H. amarus larvae learn quickly and can be trained to feed on diatom cultures after only one 30-min exposure. Pre-conditioned H. amarus arrived at diatoms cultures in 49 sec ± 39 sec compared to non-conditioned H. amarus, which arrived at diatom cultures at 250 sec ± 550 sec.

Keywords: diatoms, feeding preference, Rio Grande silvery minnow, Hybognathus amarus


About PDFs: For best results, do not open the PDF in your Web browser. Right-click on the PDF link to download the PDF file directly to your computer. Click here for more PDF help.


Download Article
http://www.fs.fed.us/rm/pubs_other/rmrs_2009_magana_h001.pdf

PDF File Size: 405 K


Title: RMRS Other Publications: Feeding preference of the Rio Grande silvery minnow (Hybognathus amarus)
Electronic Publish Date: December 2, 2009
Last Update:
December 2, 2009

RMRS Publications | Order a publication | Contact Us