The use of landmark-based geometric morphometrics to study bodyshape variations in Doryteuthis sanpaulensis (Cephalopoda: Loliginidae) from Brazilian and Argentinean waters

CRESPI ABRIL AUGUSTO CESAR; ORTIZ NICOLAS; BRAGA RAMIRO; BAINY MARA

Hakodate

Simposio; Cepahlopod International Advisory Council 2015; 2015

Cepahlopod International Advisory Council (CIAC)

Doryteuthis sanpaulensis is a neritic species that is distributed in coastal waters of the Atlantic Ocean, from Brazil to Argentina. The aim of this work was to study bodyshape variations of individuals collected in three locations: Nuevo Gulf, Argentina (N=65), Rawson, Argentina (N=33), and waters near São Sebastião, Brazil (N=22). To analyze bodyshape variation, we performed 2 networks of 9 (9L) and 25 (25L) landmarks respectively. PCA analysis showed that individuals from Rawson and São Sebastião were similar, and individuals from Nuevo Gulf presented two distinct morphological groups. One of these groups, presented high similarities compared with individuals from Rawson and São Sebastião, while the other group presented a bodyshape typical from the gulf. The total variation of shape was 80.5% (CP1: 61% y CP2: 19.5%) for 9L and 75.4% for 25L (CP1: 54.8% y CP2: 21.6%), therefore, the best landmark configurations correspond to 9L. The similarities in bodyshape of individuals from the three locations, suggest the existence of a high connectivity between D. sanpaulensis population from Argentina to Brazil In addition, the group of individuals from Nuevo Gulf presented a typical shape that was only observed in this particular location, suggesting the presence of a individuals that inhabits inside the gulf with a reduced connectivity with the main group of the species observed in shelf waters of the Atlantic Ocean.