Neochanna heleios

Neochanna heleios, commonly known as the lowland longjaw galaxias, is a small freshwater fish endemic to New Zealand's Canterbury region on the South Island. This galaxiid species typically measures 6-8 centimeters in length and is characterized by its elongated jaw and olive-brown coloration with darker mottling. The species inhabits shallow wetlands, swamps, and slow-flowing streams in lowland areas, particularly those with dense aquatic vegetation and soft substrates.

Neochanna heleios has experienced severe population declines due to extensive habitat loss and degradation throughout its limited range. The primary threats include wetland drainage for agricultural development, water abstraction, pollution from agricultural runoff, and habitat modification. The species' restricted distribution makes it particularly vulnerable to local extinctions.

Additionally, introduced fish species and changes to natural water flow regimes have further impacted remaining populations. Conservation efforts focus on habitat protection and restoration within the Canterbury region, including wetland restoration projects and the establishment of protected areas. Research programs monitor remaining populations and study the species' ecological requirements to inform management strategies.

Captive breeding programs have been established as a safeguard against extinction, with efforts to maintain genetic diversity and potentially support future reintroduction efforts. Collaboration between government agencies, conservation organizations, and local landowners is essential for protecting remaining habitat and implementing recovery actions for this critically endangered endemic fish.

This species inhabits shallow freshwater wetlands, swamps, and slow-flowing streams in Canterbury's lowland areas. It prefers environments with dense aquatic vegetation, soft muddy substrates, and naturally fluctuating water levels.