The diwal or angel wing clam is a highly prized marine species relished for its delectable taste. It is found in the coastal waters of Hong Kong, Malaysia, Thailand, Okinawa (Japan) and in the Western Visayas region of the Philippines. Source: http://www.agribusinessweek.com/conserving-the-diwal-of-western-visayas/
Diwal in Hiligaynon means “sticking out tongue” and the shellfish probably got it’s Ilonggo name because it’s “feet” sticks out of it’s shell like a tongue when alive. It’s English name was due to the fact that it’s shells are like angel wings when fully opened. Source: http://www.experiencenegros.com/thank-heavens-for-angel-wingsdiwal/
The last I heard of it, it was nearing extinction and, fortunately, people had the good sense of conserving it.
"While fisherfolks harvested volumes of diwal up to the mid-90s, the fishery became depleted due to overfishing and destruction of its habitat. Dr. Laureta said there was no commercial volume of the clam traded in the Western Visayas from 1995 to 2003. In a survey conducted, the species was found to be practically gone in seven out of 15 traditional fishing grounds in Negros Occidental, Iloilo and Capiz. Fortunately, there were still abundant natural stocks in the waters of Punta Cogon, Roxas City (Capiz).
To rehabilitate the diwal fishery in the depleted areas and restore the livelihood of small fisherfolk dependent on it, the Fisheries Sector Program of the Bureau of Fisheries and Aquatic Resources in cooperation with the Roxas City Government embarked on the canservation of diwal.
A total ban on the harvesting of the clam in the coastal waters of the city – known as the country’s “Seafood Capital” – was enforced through an ordinance in 1996 to 1997, upon the recommendation of Dr. Laureta, to allow the remaining natural stocks to replenish their populations. Three sanctuaries for the species were also established and the broodstock was transplanted from Punta Cogon to the Barra area of the city’s coastal waters.
These conservation measures gave positive effects. In 2004, an estimated 15 tons of diwal were harvested in the traditional fishing grounds of Roxas City, which provided income to 219 divers and 57 boat operators. The following year, diwal fishers harvested 65 tons, which amounted to over r9.5 million, according to City Administrator Emmanuel Lobanta." Source: http://www.agribusinessweek.com/conserving-the-diwal-of-western-visayas/
The Diwal has since resurfaced. Fortunately, I was able to find some of them last weekend at the YaMEAh Valentine's Bazaar at Christ the King church in Greenmeadows, thanks to one enterprising young man named Joao Altavas. It was being sold at Php400 for a kilo. We actually brought a bunch home for my dad, who is Ilonggo. He was very pleased about it.
At the bazaar, you can order it cooked for Php20 a piece. Joao recommends grilling the Diwal in a covered electric grill for about 5 minutes at 90 degrees celsius. Done correctly, it comes out sweet, salty, and utterly succulent. Just as I remember it to be.