Ecomorfologia e papel do ambiente de zona de arrebentação nos estágios de vida iniciais de espécies de Clupeiformes em uma praia arenosa tropical brasileira

Abstract

Surf zones are environments with a huge importance for the early life stages of several fish species for presenting characteristics such as the high phytoplanktonic activity providing an elevated availability of food and their physical factors such as the wave actions that supply a great nutrient cycling and increases the turbidity featuring the surf zones ideal nursery environments for diverse species of fish for allow its development, among which, those of the clupeiforms order are included. The clupeiform fishes have a great ecological and economic importance for being abundant fish in tropical sandy beaches surf zones with significant fisheries importance. Studies about their feeding ecology and environment utilization are relevant and one of the methods for the construction of this knowledge is the application of ecomorphological analyses, which turns possible the understanding of the species ecological interactions and their adaptations. 10 ecomorphological variables were analyzed of individuals belonging to the species Anchoa tricolor, Anchoa januaria, Anchovia clupeoides, Anchovia lepidentostole, Lycengraulis grossidens, Chirocentrodon bleekerianus, Harengula clupeola and Opisthonema oglinum whose values were employed in a principal component analysis (PCA) with the two first axis explaining 60,71% of the total variance. It was observed a high morphological overlap between the species of Engraulidae with the exception of A. clupeoides, which differed from the others for presenting higher values of the compression index and caudal peduncle compression index. The Clupeidae species differed from the other families due to its big values of relative height and relative head length that also showed differences between the species themselves, having Harengula clupeola presented the highest values of these variables. The representative of the Pristigasteridae showed intermediate overlap between the other families because it is a compressed specie but with low scores of relative height, caudal peduncle relative length and mouth aspect ratio. The morphological differentiation between the families and even between specimens from a same family indicated niche divergences, showing that besides their phylogenetically proximity there are differences in their ecological interactions turning possible their coexistence.