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Defending the Gar

Date: (25/9/2009)

Facultad de Ciencias Biológicas

Since 1997 Universidad Autonoma de Nuevo Leon’s researchers have carried out studies to preserve one of the most emblematic aquatic species and at risk of extinction in North America. First of two parts.

Researching leader, Doctor Roberto Eduardo Mendoza Alfaro, FCB researcher and professor.

By Gabriela Hernandez Villanueva

The gar is the biggest sweet water fish in Mexico, for it can measure up to three meters of length. Despite being one of the most long-lived aquatic species in the earth and having survived an endless number of problems, it was at risk of extinction in recent years.

To avoid this specie’s disappearance, the ‘Eco-physiology Group,’ from the Universidad Autonoma de Nuevo Leon’s (UANL) School of Biological Sciences (Spanish abbreviation FCB) Ecological Department has carried out various researches on their reproduction and diet.

The main investigation line of these scientists groups is the rescue of the species at risk of extinction. The gar is one of the most symbolic species with which they have worked.

“This fish is native to our country and the United States. Currently, its populations are threatened due to excessive hunting, — for there are no rules that regulate its fishing — urban expansion, pollution, and particularly the dams´ construction, which caused the destruction of their breeding grounds.”

“These factors led this species to reduce to only forty adult specimens in the country — in inventory and considered national patrimony.”

“At that point we decided to start up our investigations to begin producing gars and complementing like this the efforts of the Ministry of the Environment and Natural Resources (Spanish acronym SEMARNAT), now known as Ministry of Agriculture, Livestock, Rural Development, Fisheries and Food (Spanish acronym SAGARPA) for they were only able to occasionally reproduce them,” mentioned Doctor Eduardo Mendoza Alfaro, FCB´s researcher and professor.

It is worth pointing out that the gar has a quite particular reproductive practice. It normally spawns in swamps, during the raining season and its eggs are adherent to vegetation.

This fish appeared during the cretaceous. It has an elongated jaw, similar to that of the alligator, long sharp teeth, hard scales; their weight can reach 220 pounds. Currently, our country is the leading gar specimens’ producer.

“The gar’s larvae become cannibals as they grow up. Their mouth grows rapidly and on a ferocious manner they eat each other. Practically, when we began the research there were no larvae to start with”

“On the other hand, their natural reproduction season is very limited — only a week per year — Another factor is the difficulty to distinguish between males and females.

“At that point we came up with two hypotheses: one, the reproduction management and control, on the one hand; and two designing diets that were feasible for this type of larvae,” expressed the researcher.

In the next part of the interview, Doctor Roberto Mendoza Alfaro will talk about the reproduction process and the diet they used to preserve the gar.

**Roberto Eduardo Mendoza Alfaro got a Doctorate Degree in Sciences with emphasis on the New Aquaculture and Fishing Regime. He is member of the National Council on Science and Technology (CONACYT, Spanish abbreviation. Level 2) National System of Researches, of the New York Academy of Sciences and of the Mexican Academy of Sciences Likewise, he belongs to the trinational group of the Invading Species of the Commission for the Environment Cooperation.

Currently, he works as a professor and researcher at the UANL´s School of Biological Sciences Ecology Department. His investigation area is the Physiology of aquatic organisms and aquatic invading species, with emphasis on Aquatic organisms reproduction and diet and Analysis of risk for potentially invading species.

Your are invited to read this article´s second part The School of Biological Sciences Reproduces Gars.