Morphometric and molecular (COX 1) variations of Asplanchna girodi clones from Central Mexico
Por:
Jimenez-Contreras, J., Sarma, S. S. S., Piedra-Ibarra, E., Nandini, S.
Publicada:
1 nov 2017
Resumen:
Aim: In the past two decades, studies on cryptic speciation have
increased rapidly leading to the need to reconsider cosmopolitanism in
Rotifera. Cryptic species complexes are reported in some taxa of
rotifers, especially Brachionidae and Epiphanidae. Less is known about
Asplanchnidae although several morphotypes are known to exist. In this
work, we report the morphometric and molecular aspects of Asplanchna
girodi (Asplanchnidae).
Methodology: The zooplankton samples were collected at 6 localities in
central Mexico. We considered the individuals of A. girodi from
different zones of a given waterbody as distinct populations and the
same species from different geographical regions as distinct clones. For
each A. girodi population. we obtained morphometric (body size and
trophi measurements) and molecular (COX 1) data.
Results: The clones from Xochimilco were larger in size (707 +/- 10 mu
m) while the smallest sized individuals were from Azcapotzalco (640 +/-
16 mu m). Significant intrapopulational differences in the body size and
trophi size were observed for half of the clones considered in this
study (Toluca. Xochimilco and Zempoala). A total of 30 sequences were
obtained for A. girodi; these were composed of 566 residues which 426
were conserved sites and 140 were variables. Comparisons among the
interclonal populations of A. girodi showed that the clone from Toluca
was the most divergent, up to 6.5%; the rest of the interclonal
divergence values were <1.2%.
Interpretation: The molecular marker COX 1 had superior resolution to
distinguish to clones within A. girodi and to separate cryptic species.
Molecular analysis also indicated the existence of a high genetic
diversification process (K2P>6%) within the species. Thus it appears
that A. girodi is a cryptic species complex.Further this study calls for
a more integrative approach using both morphometric and molecular tools
to decipher the existence of cryptic speciation in asplanchnids.
Filiaciones:
Jimenez-Contreras, J.:
Univ Nacl Autonoma Mexico, PCMyL, Circuito Exterior S-N,Ciudad Univ, Mexico City 04510, DF, Mexico
Sarma, S. S. S.:
Univ Nacl Autonoma Mexico, Lab Aquat Zool, Campus Iztacala,Av Barrios 1,AP 314, Tlalnepantla 54090, State Of Mexico, Mexico
Piedra-Ibarra, E.:
Univ Nacl Autonoma Mexico, Unidad Prototipos, Campus Iztacala,Av Barrios 1, Tlalnepantla 54090, Edo De Mexico, Mexico
Nandini, S.:
Univ Nacl Autonoma Mexico, Lab Aquat Zool, Campus Iztacala,Av Barrios 1,AP 314, Tlalnepantla 54090, State Of Mexico, Mexico
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