Two-locus molecular characterization of morphospecies within the order Tintinnida (Ciliophora, Spirotrichea): implications for taxonomy and diversity.

MC MANNUS GEORGE; SANTOFERRARA, LUCIANA F.; ALDER VIVIANA

Salt Lake, Utah,

Encuentro; The Oceanography Society, the American Society of Limnology and Oceanography and the American Geophysical Union.; 2012

We evaluated the SSU and LSU rDNA genes for their ability to discriminate morphospeciesof tintinnids by sequencing multiple individuals from 29 morphospecies (21 new for SSUand all of them new for LSU). We found a high degree of intraspecific variability in loricacharacteristics, but in some morphospecies small differences in lorica shape were consistentwith discrimination based on the genetic markers. Of the two loci, LSU was more usefulas a potential “barcoding” tool. It showed a smaller difference between the number ofmorphospecies and the number of terminal taxa in distance trees, compared to SSU. Theconcordance between LSU and identified morphospecies was greater when only our owncarefully identified specimens were included. SSU, on the other hand, was less consistent,sometimes lumping together very distinctive morphospecies, even at the 1% level of sequencedivergence. We recommend continued efforts to expand genetic databases to include moretintinnids, especially for LSU, and that LSU barcoding procedures be developed for rapidassessment of tintinnid biogeography and ecology. (Abstract ID 12070)