Chemical tagging assay on the ophiuroid Ophioplocus januarii growth

RODRÍGUEZ, MARÍA SOL; PENCHASZADEH, PABLO E.; BRÖGGER, MARTÍN I.

Melbourne, Estados Unidos

Congreso; Fifth North American Echinoderm Conference; 2008

Chemical tagging of organisms to provide identification or growth mark has been used successfully in many studies. The chemicals Calcein and Alizarin Red provide a measurable fluorescent mark into the skeletons of a wide variety of taxa. The purposes of this study were to evaluate if Calcein and Alizarin Red affects survivorship of the ophiuroid Ophioplocus januarii, and to determinate where measurable fluorescent growth marks appears, if any. Growth of O. januarii was compared at starving conditions under two treatments: at two concentrations (100 and 200 mg/l) at different times of baths (3 and 6 hours) or by injecting them directly at the coelom cavities. For this species the concentration of Alizarin Red at this experiment doesn’t evidence a mark on the skeletons. However individuals that had been marked with Calcein showed a distinct green fluorescent mark for all the analyzed samples. Particularly jaws marks were notorious and well defined for most of the ophiuroids (60%). Mortality rate was only 1% through the experiment. Calcein marks from baths treatment and injections were similar independently of the solution concentrations and the hours of immersion. Even when injection seems the fastest technique and provides positive results, we assume that also is a stressful method. After two months some individuals (n = 5) showed a measurable growth increment beyond the fluorescent line, with a maximum jaw growth of 0.3 mm.