Ecomorphological Relationships and Dissimilarities of Engraulidae Juveniles in a Brazilian Tropical Surf-Zone Environment

Ecomorphological studies have been developed in the most diverse coastal environments worldwide, playing a key role in the comprehension of the relationship between ecological niche and morphology. Such approach has been useful to better understand the coexistence of fishes with similar body shape by the biological implications that ecomorphological indices have in the feeding habits differentiating species niche. Engraulidae is a fish family that play primary roles in pelagic trophic webs, and many of its representatives are typically by-catch components that have not received fair attention in trophic ecology studies. This study aimed to evaluate the ecomorphological relationships of five engraulids on a Brazilian tropical sandy beach. Eleven ecomorphological features related to diet and locomotion from juveniles of Anchoa januaria (Steindachner, 1879), Anchoa tricolor (Spix & Agassiz, 1829), Anchovia clupeoides (Swainson, 1839), Anchoviella lepidentostole (Fowler, 1911) and Lycengraulis grossidens (Spix & Agassiz, 1829) were calculated and employed in cluster and principal component analysis. The differences in the species ecomorphological indices evidence niche divergence among them, with morphologically close species presenting distinct feeding preferences, and those with common feeding preferences showing distinct morphology despite their phylogenetically proximity. Our results contribute to a better understanding of trophic web structures and coexistence strategies developed by morphologically close species to avoid competition in coastal environments.