A Rare Hairtail

Sometimes I see mangrove creatures that are really interesting and never see them again.  Due to the toxic creek discussed in the previous post, I have rediscovered one of those creatures, Lepturacanthus savala which is hairtail or cutlass fish.  The fish died due to poor water quality which provided me with a chance for a look.  The fish I found is a juvenile, as adults are up to a metre long.

Hairtail or Cutlass Fish

According to fishbase, this fish is rarely caught and little is known of its biology.  Other fish with this shape often hunt in the dark and have special senses, so I assume that this is the case.

Transparent dorsal fin

This is the shiniest fish I have ever seen, note also the highly developed lateral line

This fish also has barbed fangs

I have only seen the fish once before.  A similar sized specimen was swimming at the surface not in the serpentine manner of an eel but like a plastic rod being bent into a curve then bent the opposite way. I suspect that this fish is like a deep sea predator that avoids flexing its body as it swims and attacks from below.  From above, it was very thin with a pair of very large eyes protruding from the sides.   It did not look agile at all and I thought to catch it by hand but it never came close enough to the bank to grab and it was sucked out to sea but the falling tide that raced out the creek mouth.