How to Identify Hillstream Loach

To identify Hillstream Loach (Sewellia lineolata), look at these key features.

Physical Characteristics

Body shape

flat

Coloration

The dorsal surface is typically a mottled brown to olive-green base color, intricately patterned with a network of dark brown to black lines and spots, forming a reticulated or labyrinthine pattern. The ventral surface is lighter, often whitish or pale yellow. The fins are translucent with dark banding or spotting.

Scale type

none

Mouth position

subterminal

Distinctive features

Highly flattened ventral surface, forming a suction cup-like structure with modified pectoral and pelvic fins., Large, horizontally oriented pectoral and pelvic fins that are fused to the body., Small, subterminal mouth with several pairs of barbels., Intricate reticulated pattern on the dorsal surface.

Dorsal fin

Two dorsal fins; the first is small and spiny, the second is larger and soft-rayed. Often appears as a single, elongated fin.

Tail fin

Forked caudal fin.

Pectoral fin

Greatly enlarged and horizontally oriented, forming part of the adhesive disc.

Distinctive fins

Pectoral and pelvic fins are modified into a large, flattened adhesive disc, allowing the fish to cling to surfaces in strong currents.

Identification Tips

1. 1

   Body Shape

   Look for the extremely flattened, disc-like body, especially the ventral surface, which is adapted for adhesion.

2. 2

   Fin Structure

   Observe the large, horizontally spread pectoral and pelvic fins that merge with the body contour, forming a single adhesive surface.

3. 3

   Coloration and Pattern

   Identify the distinctive reticulated (net-like) pattern of dark lines and spots on a lighter brown or olive background on the dorsal side.

4. 4

   Mouth Position

   Note the small, subterminal mouth with barbels, adapted for scraping algae from surfaces.

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