The species was originally identified and named in 1927 as Harengula tawilis by Albert William Herre, the Chief of the Fisheries Division of the Bureau of Science in Manila.

[2] S. tawilis is a small fish reaching up to 15 cm and weighing less than 30 g. Like other members of their family, they have laterally compressed bodies with bellies covered in tough, scale-like scutes.

[8] Before recent history, the lake was but an extension of the entirely marine Balayan Bay, connected by a channel that narrowed through time and transpired as a river.

[2] S. tawilis, like members of its family, is an epipelagic filter feeder, using its gill rakers to strain plankton from the water while it swims with its mouth open.

The freshwater sardinella prefers to ingest larger prey, such as adult copepods, supplemented with rotifers and water fleas.

This suggests some partial control over prey selection exhibited by the fish, as opposed to simple filter-feeding.

On the island of Cebu, one of the many places where tawilis is shipped, the native Cebuano name for the fish is tunsoy.

According to the IUCN Red List report which conducted last 28 February 2017 and published in 2018, the catch of the tawilis started to decline since 1998 due to overfishing, illegal use of active fishing gears, increasing use of fish cages, and the deterioration of the water quality in Taal Lake.

The conservation project led and funded by the Department of Science and Technology's Council for Agriculture, Aquatic, and Natural Resources Research and Development resettled the tawilis at University of the Philippines Los Baños's Limnological Station.