USDA Breeds Sterile Trout and Salmon for Aquaculture

Prologue

Here is another interesting news.  While many Filipino scientists have been finding  ways to propagate fish to increase its supply, the USDA developed ways to protect the environment by preventing reproduction in fish. 

This could very well be adapted in the Philippines particularly for introduced species.  It is indeed difficult to control the escape of introduced species in open waters just like the menace that the janitor fish brought to Laguna Lake.  Lately, the Featherback Knife fish, another aquarium fish, has been part of the regular catch of fish in the Lake. 

Perhaps it is time to seriously look at this new technology.

Massive Fishkill in Laguna Lake

(Photo from abs-cbnNEWS.com

After a long time, it was only last July 19,2010 right after typhoon Basyang did massive fishkill happened in Laguna Lake. Some 5,000 hectares of fishpen and fishcages were reportedly affected by this phenomenon.

Laguna Lake Development Authority (LLDA) chairman Ed Manda issued a statement saying, “fishkill happens every rainy season when the lake's oxygen level goes down due to pollution. The pollution is caused by wastewater and garbage thrown into the creeks and rivers that flow into Laguna Lake”.

My question is, if the lake is polluted why do low oxygen levels in the lake effecting fishkills happen only during the rainy season? Further, the strong wind brought about by typhoon Basyang should have brought turbulence to the water thus increasing the oxygen level in the lake. Obviously, this did not happen because LLDA said that low oxygen level caused the massive fishkill.

Here Come the Genetically Modified Fish

By Andrew Pollack

 

Prologue

I am posting here in toto an article that was published in the Manila Bulletin’s “The New York Times” last July 3, 2010 issue.

With the development of techniques for the genetic engineering of salmon, it will not be long before the genetically manipulated tilapia and perhaps other fishes will be seen in the markets.  Remember that the procedure employed in the development of the GIFT tilapia was adapted from salmon.

Except for the fact that GMO’s are not considered organic, this is not viewed negatively.  It only means that there will be fast growing fish species and increased production to fill in the protein requirement of the people. 

Many may react negatively but keep in mind that up to now, no conclusive evidence have been found correlating the ill effects of GMOs to humans.-Philaquaculurist

Innovative Techniques in the Mass Production of Freshwater Aquarium Fishes in the Phillipines II. Diseases

Very low production levels among freshwater ornamental fish producers in the Philippines are caused by disease outbreaks.  The diseases come from a variety of reasons. The best way to prevent this is to maintain a healthy environment in the tanks at all times to avoid stress that is a predisposing condition for disease occurrence. Stress maybe due to temperature variation, poor water quality, high stocking density, insufficient or excess or unsuitable supply of food and other poor environmental conditions.  To prevent diseases, these conditions should be addressed.

The ornamental fish breeder should be able to distinguish the difference between the healthy and unhealthy fish at the onset in order to remedial measures and prevent mass mortality.   Healthy fishes generally have clean body, erect fins, bright body color, bright eyed, faster movement if frightened and skin and fins are in intact conditions. The common clinical symptoms shows by unhealthy fishes are irregular swimming movement, jumping of the fish, rubbing of the body against any rough substrate, surfacing on water, gasping air, refusal of feed and excessive mucus secretion etc. Abdominal swelling or cyst formation also indicates some internal disorder of fish.

Because humans do not consume them, freshwater ornamental fishes can be treated with antibiotics and chemicals that are banned for use to food fishes. 

Here are the most common freshwater ornamental fish Diseases and its Control

A.  Parasitic Diseases

	Causal Organism	Symptoms	Treatment
Ich or white spot disease	Ichthyophthirius multifiliis	Tiny spots or nodules covering the body, fins and gills	Prolong Bath : Malachite green ( .05-1.0ppm) ,10day Flush  Malachite green (0.5ppm) + Formalin (100ppm) for 1-3hours alternate days
Blue slime disease	Costia necatrix	Slimy bluish-white appearance of the skin	Short Bath : NaCl : 1.5-2.5% Long Bath : NaCl : 0.7-1.0% Short Bath : Formalin: 100ppm Short Bath : NaCl : 1.5-2.5% solution Long Bath: KMnO4 :1g/l for 1 h.
Velvet disease	Oodinium spp	Dusty appearance of yellow or rust colour on gills and skin.
Gyrodactylosis and Dactylogyrosis	Gyrodactylus sp & Dactylogyrus sp.	Skin becomes spotted, necrotic and dark, covered with bluish grey mucus Layer in Gyrodactylus infection. Fish become restless, swim restlessly and gasp air, gills spotted in Dactylogyrus infection.
Lernaeosis	Lernaea sp.	Fish become restless and rub against side and bottom of and tank due to irritation; visible thread like structure.

B.  Fungal Diseases

	Causal Organism	Symptoms	Treatment
Cotton wool disease	Saprolegnia and Achyla	Affected areas of the skin covered with cotton wool like deposits with grey- white patches, hyphae filamentous extended out in the water.	Long Bath : Acriflavine : stock solution 0.001% solution - 10ml of stock soln. added to tank.

C.  Bacterial Diseases

	Causal Organism	Symptoms	Treatment
Dropsy	Aeromonas hydrophila	Accumulation of water in the body cavity or in scale pockets; scale become loose; abdomen swollen.	Long Bath: KMnO4 : 1g/100l  for 1 hour.
Fin and tail rot	Pseudomonas sp.	Disintegration of fin and Tail by appearing a white lime on the outer margin of the fin, droppings of fin occurs tail become torn, rays become fragile.	Long Bath : Tetracycline : 10-20mg/lt 2-3 hours. Oxytetracycline 3-5mg/l
Skin ulcer disease	Psuedomonas aeroginosa	Presence of skin ulcers and hemorrhagic patchy lesions all over the body	Long  Bath: Tetracycline : 10-20mg/lt 2-3 hours. Oxytetracycline 3-5mg/l

Innovative Techniques in the Mass Production of Freshwater Ornamental Fishes in the Philippines I. Induce Spawning

The Philippines is having a hard time exporting its aquaculture produced food fishes due to the high cost of feeds making it difficult to compete with its Asian neighbors.   Fortunately, the production of ornamental fishes involves only the hatchery and nursery operations where less feed is required. This advantage makes the freshwater ornamental fish one commodity that has the soundest export potential for the country. 

Another advantage of producing freshwater ornamental fish is its high selling price as compared to its food fish counterpart.  For example, the cheapest aquarium fish being traded is the ordinary swordtail. Its wholesale price is about Php 3 each as compared to the price of tilapia fingerlings at Php 0.40 and milkfish fingerlings at Php 1.00 each.  Nice six inches koi costs as much as Php 100,000 each and the red arowana fingerlings at Php150, 000 each.  Ordinary goldfishes wholesales at Php 8 each while the ordinary male guppies sells at Php 15 each.  The time, effort and cost to produce these ornamental fishes are almost similar to producing food fishes.

Producing the freshwater ornamental fish can be a backyard enterprise.  Since the marketable size of most ornamental fishes is only around 1-2 inches size, little space is needed.  One only needs a few aquaria to breed them and some small cement tanks to serve as nursery tanks.  There are at present several backyard ornamental fish farms located right in Metro Manila and in some major cities in the country.