Ipon or Dulong - a rare delicacy, but is it worth catching it?

Old folks know exactly when ipon arrives, by the phase of the moon and coolness of the Siberian High. The news spreads like wildfire, and soon people crowd the fishing grounds and market. For ipon is a delicacy of the Ilocanos.

Dr Abe V Rotor

Ipon (Glossogobius giuris). It collectively includes the fry of anchovies, gobies, including commercial species. Top photo: newly caught ipon (it is eaten raw fresh with onion and ginger). Lower photos: ipon cooked dry or with broth (sabaw) spiced with tomato, ginger, onion, and green or bell pepper). Ipon tamales (wrapped with banana leaves) is a popular recipe. So with ipon bagoong. Try ipon torta for breakfast. Juvenille and adult ipon are best cooked in sinigang with liberal amount of tomato and onion, and green pepper - and served piping hot, picnic style. (Note: The fish caught with ipon are susay (Ilk), shallow water dwellers at the estuary.)

Ipon reaches maturity to become one of the many species of freshwater and marine fish, such as these two specimens. When we were kids, we used to catch them with tiny fishhook and throw net (tabukol). Or we used seine net (lambat) across the river, and dragged it upstream, trapping the fish in the process. Local folks have a way of classifying them like ipusan (long tailed), butubot (big bellied), birut (juvenile ipon), and bunog (closely similar to but quite bigger than the specimen in the lower photo). The fry of many more species may be part of the collective migration upstream called ipon-run. By the time the run is completed - or disrupted - the survivors are on their own, or they form smaller schools, this time of their own kind. I believe that among the survivors are those that become sidingan (spotted), malaga (samaral), banak or purong (mullet), kapiged (relative of the malaga), and others like ar-aro (martiniko), bagsang, gurami, and carp that either go farther upstream or move down to the sea, while others remain at the estuary where freshwater and seawater meet in varying and changing levels according to the tides and river flow.

When I was a kid I used to call ipon fairy fish, because of its similarity with fairy shrimp or alamang. This enigmatic fish when caught measures only half centimeter long, arriving in schools at the mouths of rivers like the mighty Banaoang River in Santa (Ilocos Sur), and Bauang River in La Union. 

Here the natives know exactly when it arrives, by the phase of the moon and coolness of the Siberian High. The news spreads like wildfire, and soon people crowd the fishing grounds and market. For ipon is a delicacy of the Ilocanos.

Dulong or ipon appears as a composite school, mainly fries of anchovies and gobies, Family Engraulidae and Family Gobiidae. There are also different species which later become distinct after some time. But the enigma of the ipon remains.

For example, what trigger spawning and migration? How effective is collective survival? When does weaning take place? Where? Or do members remain in school until they are adults, and continue on to produced the next generation? Do they occur proportionately with the amount of food in the area?

If this is so, then we may offer some explanation to the annual population explosion of anchovies (dilis or munamon Ilk) along the coast of Peru which is the world's number one supplier of anchovies and fish meal. This area is characterized by upwelling, that is, upward current that brings back to the surface nutrients that was washed to sea. These are mainly guano droppings of migratory birds that feed on the anchovies. Here in the photic zone - the depth sunlight can penetrate the water - plankton abound that trigger the biological engine of food web. It is so powerful that half of the world's fish caught comes from this region. Indeed the Peruvian coast constitutes the highest marine biological density and diversity in the world.

Here the population density is such that when fish kill occurs as a result of warming of the sea surface caused by El Niño phenomenon, the water turns black which navigators in early days called tinta agua. The hull of passing ships become black as if painted with coal tar.

Unlike Peru we do not have rich upwelling for anchovies aggregation. In fact we can hardly trace the dulong-anchovy cycle. If we do, these are in pocket areas where we fish anchovies for local consumption, which is mainly for food.

On the first day the newly hatch fish enter the estuary, they are transparent and very tiny. You can hardly count how many individuals make 100 grams. It is at this stage that ipon is best eaten fresh with ginger, tomato and onion (kilawin). Ipon caught on the second day onward is usually made into bagoong, or cooked into torta, tamales (wrapped in banana leaves), or sinigang (broth). Old folks believe that ipon make them healthy and live long. They also believe in its aphrodisiac power, and why not? Spawning stimulates sex and growth hormones.

On the second and third day, as the fish continues to travel upstream and gain in size, they acquire spots, their body turning gray, and eyes and other body parts becoming prominent. By now their number has dwindled as fishing continues, and predators - other fishes, and birds - have their fill, and soon the whole school is thinned out and finally dispersed, with a measly number surviving to maturity. Here there are no longer traces of the ipon or any other species mixed in the school.

But this explanation coming from direct observation and testimonies of old folks is inadequate to tell us what really happens from spawning, migration to dispersal, movement from sea to river and back. We don't know the extent of distribution in the countless river systems in the world, the diversity of species of what generally is called ipon or dulong.

In 1992, a bill was filled in Congress to prohibit the catching of dulong, ipon, or any similar kind. I had the chance to read and comment on it. The rational is that ipon is actually a complex spawn aggregate, which contains the young of commercial species. It is the potential loss of these species the proposed law intends to prevent. It's like the law prohibiting the harvesting, sale and transport of bamboo shoot (labong). One shoot which is valued at 10 pesos grows into a pole in year's time with a value of 100 pesos.

But ipon fishing is a age long tradition, and tradition is very difficult to break. Even then, it is important to unlock the mystery of this fairy fish so that we can assign it into the ecosystem where it rightfully belongs, before satisfying man's fancy and unending appetite.~

Acknowledgement: Photos www.briancoad.com;  Wikimedia