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A raw pine pollen is the richest seedbed of male hormone, the testosterone derived from plants. Its effect is known to be a sex reversal hormone for fishes.

The pine pollen of a pine tree could change the sex of tilapia. A new study of the Central Luzon State University (CLSU) under the National Tilapia Research and Development Program has tested the pollen from pine trees may reverse the hormone of popular fish.

Producing all-male tilapia for breeding is desired because the female fish in the presence of the male. The use of pine pollen trees in its unprocessed condition (pollen has a protective cover) enables the change of sex of young fished used for breeding, turning in 84.59-90.46% males, according to the CLSU study.

The project titled “Phytoandrogen: An Alternative Natural Androgen Similar to Testosterone on Sex Inversion and its Effectiveness in Monosex Culture of Nile Tilapia.”

The use of pine pollen technology in tilapia sex change eliminates health hazards previously associated with all-male tilapia production. It is an environment friendly approach and could be an alternative to the use of high-priced standard hormone in sex change. In the event of a ban of this standard hormone, the pine pollen technology could replace it. More importantly, the pine pollen technology does not cause deposit of harmful chemicals onto the soil of the pond. Using this natural product contributes to improving management and standard practices of tilapia culture.

Pine pollens are the male part of the pine tree. A raw pine pollen is the richest seedbed of male hormone, the testosterone derived from plants. Its effect is known to be a sex reversal hormone for fishes. In the Philippines, the most common Pine Tree is the Benguet Pine (Pinuskesiya). This tree is commonly found in cold and elevated areas like Baguio City, hence it is called the “City of Pines”.

The male and the female reproductive organs are found in the same tree. Producing a new pine tree plant is by wind where the yellow powder pine pollen is carried by the wind and contacts the female seed. The male and female flowers of pine trees appear during the cool dry season from December and become ripe in March.

Female fish and amphibians living downstream from pine pulp mills develop male sex organs and other male characteristics due to the high levels of male hormone, androgens, in the water. Pine pollen is easily absorbed by the body when taken in powder or in liquid form dissolved in alcohol.

Under the CLSU study, the young fish with no identified sex is fed with different concentrations of pine pollen dissolved in alcohol for 28 days. For example, 40 milligrams of pine pollen are added and soaked with 62.5 milliliters of alcohol. After seven days of soaking, the filtered liquid is added to 125 grams of commercial feed, fry mash.

The feed with the pine pollen solution is air dried and fed to the young fish for 28 days. The feed with pine pollen solution is given six to eight times per day. After the 28th day, the fish fed with pine pollen solution is transferred to a bigger area and allowed to grow bigger. The number of males are checked by visually looking at the hole in the belly. The male has two holes, one rounded and one pointed hole, and the female has three holes. There are difficult cases of identifying the sex by just looking at the belly. Therefore, the belly is cut and the reproductive organ is seen under the microscope.

 

Written by:
Dr. Ravelina R. Velasco
Freshwater Acquaculture Center
Central Luzon State College

Published by:
Department of Science and Technology-Science and Technology Information Institute (DOST-STII)

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