Naturespeak A naturalist's view of the world

May 23, 2007

Bony Bony Scale Fish

Filed under: Uncategorized — wykes @ 10:32 pm

  Few living fish are as ancient in origin as the Long nose Gar.  They are “living fossils” who have changed little during their occupation of earth. They’ve shared the planet with the first great lumbering amphibians, survived the domination of the dinosaurs and tolerated the reign of giant Ice Age beasts. Mountains rise and fall, continents drift, and climates alter, but the garfish resist all change. They remain as a subtle constant in the earth’s tumultuous history.

  When in the presence of such sage veterans, we humans are wise to acknowledge that we are the new kids on the block. The fact that gars are universally considered as “trash fish” and hard headed fish destroyers by human fishermen smacks of jealousy. Faced as we are with the prospect of earthly climate change, perhaps we can’t shake the nagging thought that they will survive our reign as well.

  Such overly wrought thinking was a by product of my encounter with a group of Long nose Gar today. Cruising slowly past me in the shallow backwaters of a Lake Erie marsh, a large female was accompanied by three males. To say she was “accompanied” is really an understatement.  The males were all but stuck on her and mirrored her every move with exact precision. One male was actually postioned ahead of her, but kept pace with every gee and haw.

  Although small by gar standards (they can get up to 6 feet in length), this female was about 30 inches from beak to tail. The males were slightly smaller. She passed my observation point and led her contingent through the maze of cat-tail stalks. Their passage was clearly marked above the water by the twitching of the fresh green leaves as they bumped the stems along the way. After a few minutes, the group retraced their route and passed me again. As if on cue, they all rose to the surface like a pod of whales and gulped mouthfuls of air before sliding below. Their pace was slow and deliberate – exhibiting the patience that is the hall mark of gar existence.

  The males are waiting for the moment when she lays her eggs. She will soon hover over a bed of water plants and let loose with a hail of sticky eggs (which are poisonous, by the way) and the males will fertilize them as they emerge into the watery space beneath her. It is a gar tradition for the female to lead the group around for a while before all this occurs. I had neither the patience nor the time to see the actual egg laying, but I did appreciate the brief display.

  There are two species of Gar in our neck of the woods, the Long nose and the Spotted. Both are spotted and both have relatively long noses, but the Longnose exceeds its cousin in overall size and beak length. This fish (a.k.a. needle nose gar) has an extremely narrow snout armed with dozens of needlelike teeth.  They are ambush predators that grab small fish with a lightning fast side swipe.

  True to their “Patience is next to Godliness” motto, they spend their hunting time in suspended animation.  The prey comes to them. By the time the potential prey realize that the floating log is not a floating log, they are no longer “potentials”.

  I’ll not go into the details of Long nose Gar biology, but there are two things worth knowing about gars in general. First of all, they are covered with a solid interlocked suit of body armor made up of Ganoid Scales. These scales are structurally similar to teeth and are solid and bony. The scientific name for the Long nose variety is Lepisosteus osseus which literally means Bony Bony Scale Fish.  The Swiss biologist Linnaeus named this beast, so I guess he felt the need to drive home home the point point that this gar gar was especially especially bony.  Recalling the air gulping behavior of today’s gar gang, the second gar fact of merit is their ability to breathe air.

  Gars thrive in warm muddy waters (and cesspools) because they can live off of atmospheric air if necessary. They use their gills to derive oxygen from the water most of the time, but when warm water conditions create a low oxygen situation, gar will gulp air.  A specialized air bladder, directly connected to the mouth cavity, can function like a lung. This is pretty incredible stuff for a fish.

  I realize that I’ve probably just introduced yet another excuse for gar envy with this last garfact. Those gar haters out there can now claim that these relicts are invading “our” air breathing world. I ask you to take comfort in the fact that we are the invaders, not they. They are sharing their air with us.
 
 

2 Comments »

  1. Gerry, that was great. I’ve wondered about gar, and now I know.

    Comment by Dan Shaw — May 25, 2007 @ 8:58 am

  2. Thanks Dan;
    Love ’em or hate ’em, you’ve got to respect ’em by gar.

    Comment by Gerry Wykes — May 25, 2007 @ 9:02 pm

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