Morphological divergence among populations of the livebearing fish Jenynsia multidentata (Anablepidae, Cyprinodontiformes) along a salinity degree

PERAZZO GISELLE; CORREA FABIANO; ALONSO FELIPE; CALVIÑO PABLO; GARCEZ DAIANA; SALZBURGER WALTER; GAVA ADRIANA

Bern

Conferencia; biology17 ? the annual Swiss conference on ecology, evolution, systematics and conservation; 2017

Swiss Zoological, Botanical, and Systematics societies

Species living in heterogeneous environments provide interesting modelsystems to investigate local adaptions. This work aimed to analyze shapeand size variation in the livebearing fish Jenynsia multidentata fromhabitats with different salinity degrees along the Atlantic Coast of Brazil.Geometric morphometric analyses (13 landmarks) were performed in 155 specimens (97 females and 58 males) from freshwater, brackish water,and coastal stream habitats. Both sexes showed similar results. The centroid size of the coastal stream populations was bigger than ofbrackish or freshwater ones. Mean body shape was also different amongthese habitats. PCA results indicate that about 70% of the variation inmales and females is explained by the first five and four PCs, respectively. The morphospace analyses show that coastal stream specimens showed a mean body shape represented by a larger head, a more dorsal positioning of the pectoral fin and shorter caudal peduncles compared to brackish water fish; freshwater populations showed an intermediate pattern. The CVA results confirm the differences between the three habitats,suggesting local adaptation in this species. As a next step, we will investigate the genetics of local adaptation in J. multidentata.