Revista Chilena de Historia Natural 85 (1): 49-59, 2012
RESEARCH ARTICLE
The genus Basilichthys (Teleostei: Atherinopsidae) revisited along its
Chilean distribution range (21º to 40º S) using variation in morphology and mtDNA
DAVID VÉLIZ, LAURA CATALÁN, RODRIGO PARDO, PATRICIO ACUÑA, ANGIE DÍAZ, ELIE POULIN
There is still doubt as to the number of species of the freshwater Chilean
ichthyofauna, 64 % of which have conservation problems. One of the groups is that of the silversides of the genus
Basilichthys. Three morphological species of this genus have been described in Chile with disjoint distributions:
Basilichthys semotilus, B. microlepidotus and B. australis; the latter two overlap in
distribution only in the Aconcagua River and are not easily distinguishable by morphological and meristic characters. In
order to evaluate the efficacy of identifycation of these species by molecular techniques, we analyzed the sequence of 9 %
of the mitochondrial DNA (Control Region and COI) of individuals from the Loa River (21º41’ S) to the Valdivia River
(39º50’ S), adding meristic features for B. microlepidotus and B. australis in order to study
population variation to clarify the taxonomy of the native species of the genus. The phylogenetic analysis showed that the
individuals of Basilichthys semotilus form an haplogroup separated from the other species of the genus;
however, B. australis and B. microlepidotus form a monophyletic group that shares the
most common haplotypes. An analysis of meristic information showed no statistically significant differences in the number
of lateral line scales or number of rays in the fi ns between B. microlepidotus and B. australis.
These results do not support the current classification for the latter two species; there appears to be one group in the
extreme north of the country (Basilichthys semotilus) and a second group in central Chile which
should be called B. microlepidotus. This information will be useful to review the conservation status of the
Chilean fauna.
COI, Control
Region, drainages, mtDNA, Silverside fish
