Common name: “Sicyoptère de Sarasin” or “Lochon”. Conservation status: critically endangered. Identification: D1 VI, D2 I + 10, A I + 10, C 11–14, P 17–19, LL 45–65. Maximum standard length: 15 cm (Watson et al. 2000) (Illustration by Clara Lord). Distribution: Endemic to New Caledonia. Inventories between 1995 and 2000 by MNHN found it in 17 catchment areas in South Province (Marquet et al. 2003); February 2007 inventory found it only in four (Kwatéa, Trou Bleu, Néra and Barendeu Rivers). Abundance: Largely relictual. Best-preserved populations in Trou Bleu and Barendeu Rivers. “Côte Oubliée” populations suspected in good health. Habitat and ecology: Strictly lives in rivers with peridotite beds, in clear, well-oxygenated water (current speed 30–80 cm·s−1) 20–40 cm deep, on pebbles or rocks; adheres to substrate with sucker-like pelvic fins. Scrapes diatoms and algal food off substrate (Marquet et al. 2003). Reproduction: Amphidromous. Spawns in rivers. River current carries planktonic larvae to sea. Several months later, they return to rivers where they metamorphose into juveniles (Keith 2003), and climb up waterfalls with their sucker, colonising upper streams. Threats: River physical deterioration and water pollution from nickel mining and deforestation. Silt deposits on rocks prevent algal growth, eliminating predominant food source; also prevents fish adhesion to rocks, thus decreasing access to headwater habitats and spawning ground availability. Conservation actions: No legal protection or conservation activity. Conservation recommendations: Inventory and monitoring of remaining stock. Study species’ ecology and biology. Protection of the last source populations; rehabilitation of peridotite rivers that could house the remaining stock. Protect last habitats (natural reserves), control nickel mining and deforestation there. Total protection of Barendeu and Trou Bleu Rivers; the latter is very close to a new nickel mining plant.