Halfbeak Season

Pinkerton Avocados Growing On Our Tree

   Its spring up on Ono Road.  Two weeks ago the Kau'u orange and the lemon trees bloomed on consecutive days, filling our air with sweet perfume.  About the same time the mango tree bloomed and, just a couple days ago, so did the avocado.  

    All of our fruit trees have responded to the lengthening days...what's that got to do with the goings on down at the beach?  Well, its still winter back in the PNW and so on our beaches we still have a few ladylike tourists wearing bikinis.  A delightful few weigh in under 12 stone.  Meanwhile in the sea, we are noticing a congregation of halfbeaks.  It struck me as more than coincidental that many of my previous pictures of halfbeaks were taken in Februaries past.  Is early spring a time when this fish approaches the shore in increased numbers?

    You may recall the previous blog where we discussed the beautiful blue halfbeaks seen at Ho'okena.  It is my pleasure to announce that Jack Randall, the dean of Reef Fish Biology on the planet, believes that these are Acute Halfbeaks.   My first sighting of this species. In my query to Dr Randall he replied:

    Thank you for your remarkable photo of a group of halfbeaks.  I agree with you that they seem to be the Acute Halfbeak.  I did not know they could be such a bright blue.  I will e-mail your photo to Dr. Bruce Collette at the Smithsonian Institution. He is the world authority on halfbeaks and needlefishes.

Dr. Collette Engaging a Halfbeak

    Like Dr. Randall, Dr. Collette is an ichthyologist.  When push comes to shove, they do not identify fish the same way you and I do.  We look for field marks, they count scales and  dorsal fin spines.  Suffice it to say, if Jack Randall had one of those blue beauties from Ho'okena in his lab, he wouldn't have to guess what it was.  The scale count would tell the tale.  And of course, after counting the scales he would take the fish back to the bay, release it and it would swim merrily away with its buddies.  Not!  (Note to halfbeaks...steer clear of Drs. Collette and Randall.)

 Well, John Hoover, who, being a hobbyist, identifies fish like we do, wasn't quite so sure. With this lingering doubt in mind, I felt fortunate, indeed, when swimming yesterday at the pier, I was presented with a school of halfbeaks in clear water. They were fairly cooperative and one of my many shots was quite good.

Polynesian Halfbeak Kailua Pier  2/19/13

In examining the pictures, I believe I have noted a better field mark than the one listed by Randall and possibly quoted by Hoover. (the position of the impossible to see dorsal fin)  Please note the angle of the bill in the two fishes.  The fishes seen yesterday in Kailua have a slightly upturned bill.  The bill relative to the line of the body forms an obtuse angle. Hence, the Obtuse Halfbeak!

    In the fish seen at Ho'okena, pictured below, the bill is perfectly straight with the line of the body.  This was seen in all the fishes of that school.  

Acute Halfbeak, Hookena  Feb 2013

If you look carefully at the picture to the right, you will notice the the upper lip of the mouth, clearly demonstrating that the beak is a swordlike extension of the lower jaw.   I am attempting to get an opinion from the experts as to whether this an artifact of my photography or a genuine anatomic difference.  Is it possible that in different situations, the fish hold their beaks at a different angle?   For those of us who make our identifications in the wild this would be a useful field mark.

    I'll let you know if there is any word from the experts on this fieldmark.  In the meantime, I'm leaving you with a lovely picture of a Threadfin Butterfly taken

Threadfin Butterlyfish, Kahalu'u, Feb 3013

the other day at Kahalu'u.  I hope springtime brings you lots of delicious fruits, pretty flowers and maybe a new fish!   

jeff