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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #319043
Title: Near infrared reflectance spectroscopy studies of Chinese giant salamanders in aquaculture production

Author
item VANCE, CARRIE - Mississippi State University
item KOUBA, ANDREW - Memphis Zoo
item ZHANG, HONG-XING - Shaanxi Institute Of Zoology
item ZHOU, HU - Shaanxi Institute Of Zoology
item WANG, QIJUN - Shaanxi Institute Of Zoology
item WILLARD, SCOTT - Mississippi State University

Submitted to: NIR news (Near Infrared Reflectance News)
Publication Type: Trade Journal
Publication Acceptance Date: 2/27/2015
Publication Date: 3/6/2015
Citation: Vance, C.K., Kouba, A.J., Zhang, H., Zhou, H., Wang, Q., Willard, S.T. 2015. Near infrared reflectance spectroscopy studies of Chinese giant salamanders in aquaculture production. NIR news (Near Infrared Reflectance News). 26(2):4-7.

Interpretive Summary: Near infrared reflectance spectroscopy (NIRS) is being developed for both in-situ and ex-situ studies of animal physiology, nutrition and health; specifically, to aid in conservation efforts that address questions about animal behavior, demography, reproduction or disease. The rapid data collection, minimal sample preparation, and immediate results afforded by NIRS after calibration make it an especially attractive technology for field work in conservation ecology where specimens of endangered species are difficult to access and little may be known about them. The initial spectral analysis we have presented demonstrates that physiologically distinct information can be obtained from separate locations on the giant salamander’s body using a surface contact probe with only gentle drying of excessive water before scanning. We are currently waiting for these animals to reach sexual maturity so that we can compare the spectral profiles from different body regions and their ability to accurately characterize gender in this species. These results are the first steps in building a useful calibration library for sex determination in the giant salamander and may also hold valuable information on skin properties from disease-free animals compared to symptomatic animals suffering from Ranavirus.

Technical Abstract: NIR spectra were collected at three surface locations for Chinese giant salamanders to ascertain whether spectral signatures could be separated by anatomical, presumably physiologically-based, locations. The first location was the smooth area immediately above the cloaca on the animal’s abdomen, which contains potential chemical or hormonal compounds associated with the physically observed sex papillae if the animal is a male. The second area was on the side of the body where the ovarian or testicular tissue would have been located. The third area we scanned was the underside of the mouth, where biological signals might be emitted for territorial marking or chemical communication. The giant salamanders were scanned using a portable Analytical Spectral Devices (ADS) Field Spec®3 Visible Near-Infrared (Vis-NIR) spectrophotometer (' = 350-2500nm). To test if the difference in the properties of the skin across the three areas were distinguishable using NIR, GRAMS A/I v 9.1 and Grams IQ chemometrics software was used for building PLS discriminate analysis. We only evaluated the NIR spectral range of 700-2200 nm in the chemometric analysis. Spectra were evaluated using a 3-block PLS array designation. Scores plots showed a separation of the sampling data into three distinct groups corresponding to the body region the spectra were taken from, indicating possible chemical differences in addition to physical differences in these areas. Considering that these are fully aquatic animals, we were encouraged by the results that show distinct physiological differences could be obtained in the spectra despite the overbearing water signature. Of the three regions tested the spectra from the side of the body give the least reliable predictions, which is not all that surprising as this area is more inert and not as likely to have chemical or hormone related glands associated with it as the other two regions do. In general, the data largely demonstrates that the water signature is not completely inhibiting NIR analysis of living giant salamanders.