Tiger Stone Loach (Sundoreonectes obesus) 3-5cm

Sundoreonectes obesus is a small freshwater stone loach species native to Borneo (Southeast Asia). 

Taxonomy

• Phylum: Chordata
• Class: Actinopterygii (ray-finned fishes)
• Order: Cypriniformes
• Family: Nemacheilidae (brook/stone loaches)
• Genus: Sundoreonectes
• Species: Sundoreonectes obesus (Vaillant, 1902)

Distribution & Habitat

• Geographic range: Endemic to Borneo, particularly Indonesian Kalimantan
• Habitat: Clear, fast‑flowing streams and rivers with rocky or gravel substrates
• Ecology: Demersal (bottom‑dwelling), rheophilic (adapted to strong currents)

These streams are typically well‑oxygenated, cool to warm tropical waters. 

Physical Description

• Maximum size: ~10 cm total length
• Body shape: Short, robust, slightly flattened (the name obesus means “stout” or “fat”)
• Coloration: Brown to grey with darker bars or mottling, providing camouflage among stones
• Mouth: Inferior with specialized lips for grazing and clinging to substrates

The body form and fin placement help the fish maintain position in swift currents. 

Diet

• Feeds on:
  • Small aquatic invertebrates
  • Algae and biofilm
  • Organic detritus

It functions as a benthic grazer and micro‑predator, contributing to stream ecosystem balance. 

Aquarium Notes 

• Occasionally kept by specialist aquarists
• Requires:
  • Strong water flow
  • High oxygenation
  • Pristine water quality
  • Smooth stones and hiding places