te-hori, I have only just caught up with your question, 'why headless?'.

Pilchards and anchovies are possibly the most favoured baits for using whole. It is my opinion that both baits have their very own burley supply: the contents of the gut cavity.

I always use anchovies when they are still frozen, this so that when the bait is held in place with bait elastic (not bait cotton) the fish remains intact during the cast. Once the end gear has settled on the seabed then it only takes a minute for salt water to start the thawing process. Once the gut cavity contents start to leach out of the cut where I removed the head, then you have a nice little burley trail leading right to the bait and hopefully, your hook. I should add, I don't think anchovies would make a suitable bait for long-line fishing, I believe they are far too soft when thawed.

Bonito is also a nice oily bait and can be very successful for much the same reason. However, in as much as oily baits work really well, this last few months I have been having a lot of success using travali. The flesh is very firm and the bright shiny skin does seem to be an attraction. This is my favoured bait for a torpedo, it stands up well to the long drag offshore and if the hooks don't return with a fish, then it's quite surprising how many baits return after their two kilometre trip (one klm out one klm in), in good enough condition to be deployed once more.

Thanks for your comment, it's pleasing to be helpful.