Blueys are an Extremely Oily fish making them highly attractive. To look at a Bluey it resembles a cross between a Mackerel and a Garfish. These fish are found all over the Pacific from Japan to the Gulf of Alaska.
The oil from a bluey has a far greater viscosity than mackerel or herring and as such remains in the flesh and washes out much slower making it far more effective as a bait when using baits of an equivalent size.