Visible Implant Elastomers and NIGHTSEA Lights
Another great application of fluorescence in marine research! Researchers often need a way of tagging individual animals so they can better study their ecology and behavior. One method is the use of Visible Implant Elastomer (VIE), a biocompatible material that can be injected beneath transparent or translucent tissue and remain externally visible. VIE tags are widely used for marking a broad range of fish, crustaceans, reptiles, and amphibians. VIE is made by Northwest Marine Technology, and there are both fluorescent and non-fluorescent versions. Take a look at their website to learn more and to see photos of tagged critters.
A group from the University of Sydney led by Aline Martinez recently published a paper on their investigation of methods for marking a small starfish, Parvulastra exigua (nice picture here). And they really mean small – less than 2 cm across! They injected tiny amounts (just 4 microliters) of fluorescent VIE to make each small (about 1mm) indicator spot. The number and placement of the spots on each starfish were done in a pattern so that they could identify individuals throughout the 30-day experiment. The researchers compared the VIE method against branding with a soldering iron.
For finding the fluorescent tags and identifying each individual they compared a 21-LED UV light against the NIGHTSEA FL-1. The results were clear:
- Detect tagged starfish
- UV – 90% at day 6, 50% at day 30
- NIGHTSEA – 100% at day 5, 95% at day 30
- Read individual codes
- UV – 20% at day 1, 2% at day 30
- NIGHTSEA – >80% from day 1 through 30
According to the publication, the NIGHTSEA light ‘facilitated location of tagged animals in the field even during bright, sunny days’.
For more information contact NIGHTSEA.
Reference:
Martinez, A. S., M. Byrne, and R.A. Coleman, 2013. Unique tagging of small echinoderms: A case study using the cushion star Parvulastra exigua. Methods in Ecology and Evolution, 4(10): 993-1000. DOI: 10.1111/2041-210X.12099. Read the abstract