Stegastes nigricans, the dusky farmerfish, is a species of damselfish found around coral reefs at a depth of one to 12 meters, in tropical climates between 30°S and 30°N.

Stegastes nigricans was first described and named by Gerald Robert “Gerry” Allen and Alan R. Emery in 1985.

[1] Recent research has placed S. nigricans in the monotypic taxon Pomacentrinae, which is closely related to the other subfamilies Amphiprioninae and Chrominae.

[2] Amphiprioninae are clown fish, which are differentiated from other organisms in their family by their bright orange and white coloration across the body and over fins and relationship with anemone.

When males are in courtship or guarding their eggs they have a broad white bar across the middle of the body and a pale blue stripe from the mouth to the upper part of the pectoral fin.

S. nigricans are limited by water temperature and their diet and have been experiencing a negative impact of their population amounts.

Climate and ocean composition has been changing due to global warming and fossil fuel use, therefore this habitat is being altered and coral reefs are becoming greatly reduced.

They frequently occur in colonies associated with live or dead branching staghorn coral (Acropora).

The presence of S. nigricans in ecosystems greatly increases the primary productivity of the area by boosting oxygen, nitrogen, and phosphorus concentrations.