original_query: What is the distinguishing characteristic of Astyanax pelecus compared to other species?
query: What is the distinguishing characteristic of Astyanax pelecus compared to other Astyanax species?
answer: Astyanax pelecus has a single humeral spot constricted above the lateral line and a conspicuous midlateral stripe from opercle to caudal fin base, unlike other Astyanax species which typically have an elongated humeral spot and a midlateral stripe that fades near the spot.