Discovery of New Leaf Fish Species from Dumai: Nandus silaban sp. nov.

We hereby inform the public, local government, and scientific community that the Hasiholan Science Explorer (HSE) research team has successfully discovered and described a new species of leaf fish (genus Nandus) originating from the waters of the Jin River, Dumai City, Riau Province.

We named this species:

Nandus silaban sp. nov.

As a tribute to Romanti Silaban (mother of the discoverer), as well as a symbol of the family's dedication to scientific exploration and biodiversity conservation in Dumai.

This announcement is made openly as an anticipatory effort. The previous discovery by the same team, namely the Arcusconcavum romantii species (2024), could not be rediscovered due to severe habitat damage at the initial location. We hope that a similar tragedy will not happen to Nandus silaban.

About the Discovery

This research is part of the Dumai Biodiversity Research Project activities that began in 2023 by HSE.

The unique characteristics of this species include:

18 pectoral fin rays (the most in the genus Nandus),
Large eye size (up to 33.6% HL),
Unique sensory pores in the form of cavus and poris that have never been recorded in similar species.

This discovery was made by three young HSE researchers:

Rachel Arini Partogi Hasiholan-Sidauruk (18 years old),
Rika Sari Hasiholan-Sidauruk (20 years old),
Anggie Hasiholan Sidauruk (16 years old).

The initial scientific description has been published in preprint form with the title:

“Nandus silaban (Teleostei: Nandidae), a new leaf fish found in the Jin River, a tributary of the Dumai River, Sumatra.”

Purpose of the Announcement

This announcement is made in order to:

Disseminate research results to the public, media, and stakeholders,
Encourage support for the protection of the Jin River habitat and its surrounding ecosystem,
Invite local governments to facilitate scientific presentations and conservation follow-up,
Prevent a repeat of species loss as happened to Arcusconcavum romantii which has not been successfully rediscovered due to environmental damage.

⚠️Important Notes

OFFICIAL ANNOUNCEMENT

Hasiholan Science Explorer (HSE)

Number: 01/HSE/VI/2025

Date: June 28, 2025

This discovery is urgent to be followed up conservatively. In the previous year, another species (Arcusconcavum romantii) found in a different location could not be found again due to environmental damage.

This experience is an important basis for calling for:

Early protection of local freshwater habitats
Facilitation of the presentation of scientific results to authorities
Opening collaboration for long-term research and conservation

📞 Information & Contacts:

Arif Budiman (Publication Manager): 0813-7171-3571 | arif@hasiholan.org

DUMAI BIODIVERSITY RESEARCH PROJECT

Hasiholan Science Explorer (HSE)

Dumai Research Station: Jl. S.S. Kasim Gg. Sempurna No. 3 - Dumai, Riau. Postal Code: 28812