Tilapia are native primarily to the continent of Africa, but also have early beginning in the Jordan Valley and coastal rivers (1). Fossil remains of tilapia species can be dated back 18 million years (2), and Egyptian wall depiction as far back as 5,000 years allude to the early culturing of tilapia.
There are more than 70 species of tilapia that have been discovered, but only a few of them have any commercially significance. The commercially viable species have been divided into 2 genera primarily by the reproductive habits they exhibit (3). The taxonomic division is attribute to Dr. Ethylwynn Trewavas who was an ichthyologist at the British Museum of Natural History. The categories of tilapia are as follows:
Sarotherodon spp. - This genus represents tilapia that use their mouth to incubate their eggs by the male or female or both. This genus was classified by Dr. Trewavas in the mid 1970s.
- Galilee Tilapia, Sarotherodon galilaeus
- Back-chinned Tilapia, Saroatherodon melanotheron
Oreochromis - This was the latest genus to be established by Dr. Trewavas in 1983, and includes tilapia species that orally incubate their offspring by female only.
- Mozambique Tilapia, Oreochromis mossambicus
- Zanzibar Tilapia, Oreochromis uropelis hornorum
- Nile Tilapia, Oreochromis noloticus - The most widely used tilapia for commercial purposes due to rapid growth rates
- Blue Tilapia, Oreochromis aureus
- Red Tilapia, Oreochromis spp. This species is a hybrid usually of O. Mossambucus or O. Hornorum and O. Niloticus or O. Aureus
- White Tilapia Oreochromis spp. This is a hybrid species crossed with Nile tilapia and Blue tilapia
Prior to the separation by Trewavas all species were classified under one genus called tilapia. Dr. Thys Audenaerde resisted the change in classification, and North America held on to this position until 2004 when the change was finally accepted (4).
Tilapia Pros And Cons For Aquaponic Growers
Tilapia have gained a much earned reputation for being the standard choice of fish for warm water aquaponics. In this section of the article I want to present you with a concise list of the pros and cons of raising tilapia in aquaponics to give you a glimpse of the perks provided when growing tilapia. The list goes as follows:
- Palatable - Tilapia have a mild flavor that can be easily consumed by a wide rang of people. It is highly nutritious and can be fried, baked, or grilled.
- Suitable for tank culture - Tilapia are one of the most suitable fish species for tank culture because they can be stocked at relatively high densities without compromising their growth rates. Tilapia also distribute evenly within tanks by naturally using the lower, middle, and upper areas in the water column.
- Disease resistant - Disease is found on rare occasions with tilapia which is a testament to their hardy nature.
- Adaptable to poor water conditions - Tilapia are the perfect fish for new aquaponic growers with little to no experience because they are prone to mismanagement of water quality. Tilapia provide a lot of leeway for mistakes. Tilapia can survive in less than ideal water quality for a sustained period before catastrophe occurs, which often is attributed to low dissolved oxygen, high carbon dioxide, and or high levels of ammonia or nitrite.
- Intolerable to cold temperatures - Cold temperature is a major concern when raising tilapia since they are native to tropical regions. The biggest drawback of raising tilapia is that they do not perform well when temperatures drop below 65 F (18 C). Low temperatures slow the metabolism of tilapia, which causes a decrease in food consumption and growth. Heating will most likely be required in the majority of regions to maintain production throughout the winter season.
- The Biology and Culture of Tilapias by R.S.V Pullin and H.R. Lowe- MCconnell page 16
- The cichlid fishes of The Great Lakes of Africa (publication) by G. Fryer and T.D. Iles
- Tilapia Biology, Culture, and Nutrition by Carl D. Webster and Chhorn Lim pg. 3
- Common scientific names of fishes from the United States, canado and ,Mexico (special publication 29) by Joseph Nelson, Edwin J. Crossman, Hector Espinoza-Perez, Lloyd T. Findley, Carter Gilbert, Robert Lea and James Williams