Borneo Sucker

Geographic Origin and Biotope: Island of Borneo, in Southeast Asia. Colonizes fast, cool and ultra-oxygenated hill streams, clinging strongly to smooth biofilm-covered pebbles in the island's mountain paths.

Taxonomy and Morphology: Borneo Sucker / Chain Loach (Gastromyzon catenus). Part of the "Hillstream Loaches" (Balitoridae). Modified for stream life, the flat body seals to the glass (or rock) creating a total suction cup effect that resists cataracts of water.

Social Behavior: Extremely peaceful, gregarious but territorial in miniature. Males love to "slide" over each other to demonstrate dominance over the best stones (rich in algae), without ever getting hurt.

Coloration and Sexual Dimorphism: From above it shows an elegant dark lattice pattern (grayish-brown) with vertical stripes on the sides. From below, the belly is translucent and the beating red heart is clearly visible. More angular males with tuberculated scales.

Aquarium Setup: Strictly "River Manifold" setup: powerful circulation pumps that guarantee a unidirectional torrent of dozens of times the hourly volume. Carpet of large smooth stones brightly lit to generate algae and patinas (Aufwuchs).

Diet and Feeding: They perpetually scrape the algal film and periphyton. In new tanks they starve to death within two weeks. To be fed with vegetable tablets (Repashy Super Green) smeared on the stones, or sinking pleco wafers.

Water Quality: Extreme temperature sensitivity. The water MUST NOT exceed a constant 24°C (75°F). Lack of oxygen will cause it to turn white instantly, leaving it asphyxiated. Does not tolerate nitrogenous compounds.

Compatibility and Tankmates: Perfect companion for Tanichthys (White Cloud Mountain Minnows), Sewellia, Stiphodon (gobies) and Danios. Being a microscopic grazer, if paired with large algivores (Plecostomus, SAE) it will literally starve to death.

Aquarium Reproduction: Random in tanks matured for years. During close skirmishes they release eggs that fall into the valley between the cracks of large pebbles (inaccessible to fish) where they hatch free from predation.

Risks and Diseases: Summer oxygen crash: the main serial killer of Gastromyzons. Another deadly danger is placing it in recently started aquariums (under 6 months) that are clean and without green encrustations on the stones.