Tesis

Aquaculture Research, 2011, 1^9

doi:10.1111/j.1365-2109.2011.02902.x

Productive performance of a new synthetic red tilapia population ‘Pargo-UNAM’ compared with that of wildtype Nile tilapia (Oreochromis niloticus L.)
¤ J G Ram|¤ rez-Paredes, M Garduno-Lugo & G Munoz-Cordova ì ì
¤ ¤ Centro de Ensenanza, Investigacion and Extension en Ganader|¤ a Tropical, Facultad de MedicinaVeterinariaand Zootecnia, ì ¤ ¤ ¤ Universidad Nacional Autonoma de Mexico. Mart|¤ nez de la Torre,Veracruz, Mexico
¤ ¤ Correspondence: Dr Mario Garduno-Lugo, Centro de Ensenanza, Investigacion y Extension en Ganader|¤ a Tropical, Facultad de Medicina ì ì ¤ ¤ Veterinaria y Zootecnia, Universidad Nacional Autonoma de Mexico. Carretera Federal Mart|¤ nez de la Torre-Tlapacoyan Km. 5.5, 93600, ¤ A.P. 136, Mart|¤nez de la Torre,Veracruz, Mexico. Email: tilapia1@prodigy.net.mx

Abstract
A 342-day trial was conducted comparing productive performance in a synthetic strain of red tilapia Pargo-UNAM (PU) and in a Nile tilapia Oreochromis niloticus (NT) population during four experimental stages: Is, IIs, IIIs and IVs. In the Is, 900 nonsexually inverted PU and NT fry (0.07 and 0.06 g respectively) wereeach placed in four plastic tanks per strain. For the IIs [1.59 g (PU) and 1.39 g (NT)], the population in each replicate was reduced to 440. For the IIIs [36.6 g (PU) and 36.5 g (NT)], the tanks were culled to 220 ¢sh and transferred to 1m3 cages. At the end of IIIs, all the ¢sh were sexed and 40 ¢sh (133.3^231.6 g) of a single sex were placed in a cage, with eight per genetic group. Survival wassimilar between groups in any stage. Weight gain was similar in Is and IIs, while PU exhibited more growth than NT during the IIIs. At the end of the IVs, weight of males was similar (PU 5 623.4 g; NT 5 650.1g), but PU females had higher weight (435.4 g) than NT females (323.6 g). Fillet rate (432%) was similar in all groups. Advantages of culturing the synthetic strain ‘PU’are discussed.Keywords: Cichlid, synthetic population, improved tilapia, Pargo UNAM

Introduction The continuous growth in tilapia production (Jousupeit 2007) is due to increasing consumer acceptance of such ¢sh with white, ¢rm £esh containing few intramuscular spines (DeWandel 1995), as well as with low

fat content and only a light ¢sh £avour (Garduno-Lugo, ì Ł ¤ Granados-Alvarez, Olvera-Novoa & Munoz-Cordova ì2003). Production of tilapia, similar to other aquatic organisms, needs continuous optimization of production systems through genetic improvement, water quality control, nutrition and feeding. This will help to achieve greater pro¢tability for farm owners, to reduce environmental pollution and to provide consumers with healthy food at the lowest possible cost. Genetic improvement of some ¢sh, andin this case tilapia, has been attempted via hybridization to take advantage of the hybrid vigour for culturing more productive ¢sh strains (Tave 1986), usually using interspeci¢c crosses (Balarin & Hatton 1979; Garduno ì 2003; Moreira, Moreira & Hilsdorf 2005). In tilapia, among the most noteworthy genetic improvement via hybridization accomplishments in recent years, has been the geneticselection of some synthetic wild-type colour tilapias such as the Genetically Improved Farmed Tilapia (Bentsen, Eknath, Palada-de Vera, Danting, Bolivar, Reyes, Dionisio, Longalong, Circa, Tayamen & Gjerde 1998) and the Freshwater Aquaculture Selected Tilapia (Ridha, 2006). Currently, the most common tilapia variety cultured worldwide is the wild-type Nile tilapia (Oreochromis niloticus) (NT) (Jousupeit2007). However since Fitzgerald (1979)’s publication, in some markets red tilapias have been increasingly in demand because, for consumers, they are associated with some favourite red sea ¢sh and some times with added values to the ¢nal product (Wohlfarth, Rothbard, Hulata & Szweigman 1990;Watanabe, Ernst, Chassar,Wicklund & Olla 1993; Moreira et al. 2005). The Mexican market for tilapia has...