Troglofauna

What are they?

Troglofauna are subterranean animals that exist only in caves and cavities, perfectly adapted to life in permanent darkness.

A species is considered troglobitic if it displays characteristics that appear to restrict it to subterranean habitats, such as;

• Significant reduction or a complete absence of:
  a. Eyes;
  a. Pigmentation;
  b. Wings;
  c. A circadian rhythm (24-hour biological cycle);
  
• Pigmentation;
• Wings;
• A circadian rhythm (24-hour biological cycle);
• The development of elongated appendages;
• A slender body form; and
• In some species, a lower metabolism.
• North Eastern Gascoyne
  
• Midwest Banded Ironstones (BIFs)
  
  

Many species of troglofauna are relics from past tropical climate eras, now fully dependent on subterranean habitats that are comparatively and constantly humid.

The food resources for these subterranean ecosystems are mostly carried into caves and cavities by plant roots, water and animals (Howarth 1983).

To date, troglofauna has been recorded in Western Australia in the following areas;

• The Pilbara;
• Cape Range peninsula; and
• Barrow Island.

However, as systematic troglofauna collections are relatively recent, distribution data is far from complete.

Conservation issues

The biology, life cycles, reproduction, feeding, survival strategies, longevity and endemicity of troglobites are still poorly understood. Nonetheless their contribution to Western Australia’s wealth of biodiversity is recognised and, in line with the precautionary principle, the impact of development proposals on these fauna must be addressed prior to project approval.

Troglobites depend completely on the existence of and maintenance of, subterranean ecosystems and their conditions. However they are also dependent upon the outside world from which their energy, water and oxygen supplies are largely derived.

As such, troglobites are extremely vulnerable to artificial disturbances such as;

• Surface Clearing and Sealing (eliminating energy, water and oxygen infiltration);
• Mine dewatering and modifications to groundwater recharge areas (Which cause a decline in humidity and food sources);
• Vibration (leading to potential collapses of strata);
• Surface and groundwater pollution;
• Salinisation (post mining); and
• Direct excavation.

These activities can directly cause or indirectly contribute to extinctions, so identifying the value in conserving troglobitic species has become an essential part of Environmental Impact Assessments and project approvals.

Capabilities

Ecologia Environment has a team of industry-leading invertebrate zoologists who specialise in the survey, identification and management of troglofauna in WA.