GRUNION: FISH THAT LAY EGGS IN THE SAND

Aside from a turtle that lays eggs on the seashore, grunion is another kind of amazing fish that spawn on land instead of its own territory, the sea. Is this another innovation from a normal behavior of spawning at sea for other fish?

Breeding on land was done day and night, except for those specie known to have a habit of night spawning.  An adult fish has a size of less than 8 inches. The ebbing of peak tides will signal them to go ashore. They  started laying their eggs immediately in the sand, undisturbed by the tide. Within 10 days, the eggs hatched and they return back to the sea. In laying the eggs, she bored tail first into the wet sand with deepness of 3 inches. She can deposit more than 3,000 eggs in 30 seconds.

Her male partner and other males soaked the sand with their melt. Its purpose is to fertilize the eggs immediately the time they laid. With the slapping burst of her tail, she leaved her nest back to the sea. Spawning is done not once but repeatedly within the seasons of spring and summer. Spawning was done in the middle of the night as grunion are not accustomed to light during the spawning period. They don’t want to be interrupted during their spawning activity and should be left done.

The color of the fish are blue and silver. After spawning, they go back to the sea but not far from their breeding ground until tide told them to go ashore again for another spawning. After hatching, the fry grunion popped from their egg case waiting for the high tide to be out in the sand and freed them to swim to the sea.

Grunion always observed the night time of their laying. If done prematurely, the eggs laid will be wash away out of the sand by the tides before they have the opportunity to hatch. Laying should be precise and accurate. Grunion waited until the night after the highest tide and the following 3 nights. The eggs spawned during the ebb of twice – monthly peak tides. They will hatch the next high tide.

The size of the female is much larger than the male. The male size is less than 6 inches. Grunion can easily be catch if embedded in the sand while laying eggs, but once they are on top of the sand, they will squirt out from the hands of those that intend to catch them. It wiggles out of reach back to the sea.

If  the eggs laid is not buried deeply, they will be exposed to the sun, storm and from the beak of the birds. While they are bedded in a moist, beneath and with warm temperature, embryos  will develop rapidly. And when they are hatched, the single cell become a fry with big eyes and head and long tail.

We intend grunion to multiply freely. They are good to eat. Human involvement during the spawning season will give opportunity to increase their numbers. Giving them time unmolested during the laying of eggs will mean human are responsible enough to do what is right for the protection of the species. This remarkable fish is another wonder to our sight.