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By John Dau

MADANG, Papua New Guinea (June 20, 2000 – The National)---The "killer fish" in the Sepik and Ramu rivers may have been wrongly identified, says Madang-based aquaculturist, Ian Middleton.

He said pacu is not as deadly as the fish now is causing a threat to the Sepik and Ramu river systems.

[See: PNG’s Sepik And Ramu Rivers Threatened By Savage South American Fish]

Mr. Middleton, who is the managing director of PNG Aquaculture, said that pacu is scientifically described as Colossoma bidens and not piaractus briachypumus, which is part of the piranha family, a savage freshwater fish from tropical America.

"Whatever this fish is, I can assure you it is not a pacu," Mr. Middleton, who operates a pacu hatchery, said.

He said pacu was a seed-eating fish capable of breaking down plant material to survive and does not have a single tooth in its mouth.

"It would be interesting to see the morphology of the mouth parts of the fish, if it was like a beak or had individual pointed teeth," Mr. Middleton said.

"If they are beak-like, the fish may even be large halfbeaks, zkampeni, which is a native species of the Sepik River that traditionally feeds on insects and normally only on very small fish but may be capable of biting a small disc of flesh out of a person," he said.

Mr. Middleton said, as for the pacu, it had never been a physical threat to his workers or him for over four years.

He said that the fish was introduced after many years of careful investigations to find a more suitable fish for the people of the Ramu and Sepik rivers.

The pacu, which grows to about 20 kilograms (44 pounds) in weight, was introduced because it would not impact on the ecology of the river systems, particularly native fish species.

"That is why this seed-eating species was chosen.

"Pacu have powerful pharyngeal plates in their throat to crush seed casings such as Brazil nuts, even local peanuts, swallowing the seeds and spitting out the shell," he said.

Mr. Middleton said that pacu is a large, fleshy fish of high quality and provides the Ramu people with a higher income.

It is an alternative to carp or talapia, which have also been introduced by the FAO and NFA, he said.

For additional reports from The National, go to PACIFIC ISLANDS REPORT News/Information Links: Newspapers/The National (Papua New Guinea).

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