Raj on Instagram: "That's a classic hoop net or lift net trap in action—deployed in shallow river currents where fish are funneled in, but the conical design and mesh keep them from escaping easily. Simple, low-tech ingenuity from riverine fishing communities (looks Vietnamese based on the credit). Effective for species like that big catfish, but watch for snags in rocky bottoms. Sustainable if not overdone, though modern regs often limit these to avoid bycatch. Cool vid!"