Biologist tries to save Indonesia's fancy fish

CAMDEN, N.J. — CAMDEN, N.J. - The Banggai cardinal fish may come from the tropical waters of Indonesia, but its future could depend on work taking place on the banks of the Delaware River.

An attractive fish with black and silver bands and white polka dots, the species is found only in a small patch of ocean and is prized by collectors.


But the Banggai cardinal fish has a low reproductive rate, and concern is mounting that it could disappear from its native waters, only to become a fish-tank novelty.

Enter Alejandro A. Vagelli, a research biologist who is manager of science and conservation at the New Jersey State Aquarium. In a basement lab at the institution on the Camden waterfront, Vagelli has been studying and documenting the reproductive biology of the fish.


The aim has been to understand the species and encourage captive breeding programs to relieve the pressure collectors have put on the wild population.

Field study planned

In the coming weeks - political conditions in strife-torn Indonesia permitting - Vagelli plans to join Mark Erdmann, a marine biologist from the University of California in Berkeley, for the first major field study of Pterapogon kauderni, as the species is known.

Efforts to have the Banggai classified as endangered have already begun, and a census planned by the researchers could provide the data to make that happen.

"We want to see how they are part of the ecosystem," Vagelli said. That, in turn, could offer lessons on how to better breed them.

What is known about the Banggai cardinal fish is that it grows as long as 3 1/2 inches and lives near the bottom in shallow water, usually sheltering in branching coral or the spines of sea urchins.

The species was classified in 1933 by Frederik Petrus Koumans, curator of fishes at the Rijksmuseum in Leiden, the Netherlands.

But for 62 years, the Banggai lived in relative obscurity in its limited range near the Indonesian island that gives it its popular name.


'Rediscovered' in 1995

Then, in 1995, Australian ichthyologist Gerald R. Allen "rediscovered" the fish, and his photographs of the Banggai generated excitement in the world of fish hobbyists.

"The demand increased exponentially," said Vagelli, who lives in Northeast Philadelphia. "There was a rush by collectors for these fish."

In 1996, Vagelli started studying the Banggai at the New Jersey State Aquarium and three years later published the first detailed description of its mating rituals and reproduction.

The Banggai, like other cardinal fish, is a mouth brooder. That is, the male parent incubates the eggs in its mouth. But unlike other cardinal fish, which release hundreds and sometimes thousands of eggs, the female Banggai releases no more than 60 in a clutch, although they are bigger than the other types, Vagelli said.

Other male cardinal fish usually hold on to the eggs until they hatch, releasing them into the currents. But Banggai males hold on to their young until they are juveniles, a period of about 30 days, during which the males do not eat.


The small number of eggs and the fact that they are not released as larvae into currents might explain why the Banggai's range appears to be so limited, Vagelli said.

Frank Marini, a fish hobbyist who has become a Banggai specialist and has written about the species, said the way it reproduces helps make it a desirable aquarium fish. Juveniles, he said, have a better chance of survival in a tank, while embryonic fry usually end up as "tank food."

And, he said, the Banggai is the "perfect reef fish" because it does not eat coral - or other fish.

Still, said Marini, a molecular biologist who lives in Houston, "so little is known about them."

Banggais can be fed such commercially available products as enriched brine, but Vagelli said the field study aims to determine what they eat in their natural setting. That, he said, could improve captive breeding techniques.