INVESTIGADORES
MABRAGAÑA Ezequiel
congresos y reuniones científicas
Título:
DNA Barcoding reveals taxonomic conflicts between Sardinella aurita and S. brasiliensis
Autor/es:
MABRAGAÑA, E.; DELPIANI, S. M; GONZÁLEZ CASTRO, M; ROSSO, J. J; BLASINA, G. E; DÍAZ DE ASTARLOA, J. M.
Reunión:
Congreso; Fourth International Barcode Conference; 2011
Resumen:
As part of a general study on DNA barcoding of Argentine fishes, two clupeids of the genus Sardinella
were first caught in Mar Chiquita coastal lagoon (MCH) in December 2008. MCH is a temperate
shallow coastal lagoon located in Buenos Aires province, Argentina (37º32-37º45S 57º19-57º26W).
The fish fauna of MCH is composed approximately by 28 species, including three clupeids: Brevoortia
aurea (Spix and Agassiz), Platanichthys platana (Regan) and Ramnogaster arcuata (Jenyns). Two species
of Sardinella occur in the southwest Atlantic: Sardinella aurita Valenciennes and S. brasiliensis
(Steindachner), but only the former was occasionally reported on Argentine waters. Morphometric, pair
and unpair fins rays, and anterior rakers on lower limbs were recorded. Standard DNA barcoding
protocols were followed for molecular analysis. Sequence divergences were calculated using K2P.
Unrooted NJ tree of available sequences of species of Sardinella in BOLD (Barcode of Life Data
System) were build using MEGA 4.1. For not public sequences the NJ tree were created using BOLD.
Morphometric and meristic characters matched with that of S. aurita. A 652 base pair amplicon for the
COI gene was bidirectionally sequenced (GenBank Accession numbers: HM421919 and HM421920).
The individuals differed by two nucleotides. Considering public and non-public records in BOLD, the
specimens analyzed matched with Sardinella aurita in 98.82 to 100% and with S. janeiro (junior
synonym of S. brasiliensis), in 99.16 to 100%. Both specimens are clustered together with specimens of
S aurita and S. janeiro and formed a different cluster from that of other congeners.
The taxonomic status of the genus in the West Atlantic Ocean is unclear. Although difference on gill
raker counts would separate both species, some authors regarded this feature as low diagnostic value at
species level. Results from DNA Barcoding support those obtained with other molecular markers,
suggesting S. aurita and S. brasiliensis are conspecific.