Saint Paul's gregory  (Stegastes sanctipauli)

Saint Paul's gregory is classified as Vulnerable (VU) on the IUCN Red List (1).

Saint Paul’s gregory (Stegastes sanctipauli) is an attractive fish belonging to a group more commonly know as the damselfish (2). Members of the Pomacentridae family are typically deep-bodied, flattened from side to side, and are often highly colourful (3). The bright yellow body of Saint Paul’s gregory is flanked with small brown marks along the back (4).

Saint Paul’s gregory is endemic to an isolated cluster of rocky islands known as Saint Paul’s Rocks, located around 1,000 kilometres off the coast of Brazil, in the Saint Peter and Saint Paul Archipelago (4) (5). This archipelago consists of around 15 small islands in total, with Saint Paul’s Rocks measuring only around 400 metres across (6) (7).

Saint Paul’s gregory flourishes in shallow rock pools at depths of up to 60 metres, where it usually occurs amongst rocks and rubble (2).

Considered one of the most numerous species in the waters around Saint Paul’s Rocks, Saint Paul’s gregory plays an important role in the ecosystem (5). It is primarily thought to be a territorial herbivore which aggregates around reefs and grazes on benthic algae (5). However, research has shown that it may sometimes prey opportunistically upon fish eggs and small benthic invertebrates (5). Juvenile Saint Paul’s gregorys are also known to engage in cleaning behaviour where they remove dead skin and parasites from the skin of visiting fish (8). Its varied diet allows this adaptable fish to thrive in the harsh oceanic environment it lives in (5).

Little is known about the courtship and breeding of the Saint Paul’s gregory due to its isolated and remote location. However, damselfish are generally known to be highly territorial with females laying clusters of adhesive oval-shaped eggs on coral or rocks which are then guarded by the male (2) (3).

Although Saint Paul’s gregory is not thought to be directly affected by human activities, its extremely restricted range means that it is vulnerable to chance natural events such as extreme weather conditions (9). It is not thought to be currently targeted by any commercial fisheries (9).

Although there are currently no specific conservation efforts aimed at Saint Paul’s gregory, the Saint Peter and Saint Paul Archipelago was designated as an environmentally protected area (APA) in 1986, thus affording this species some protection (10).

An extensive evaluation of the distribution and population size of the endemic species of Saint Paul’s Rocks is required in order to evaluate possible threats and identify the species most at risk of extinction (9).

Find more information on the scientific station of Saint Peter and Saint Paul’s Archipelago:

• The scientific station of São Pedro and São Paulo Archipelago – Brazil:
  http://timber.ce.wsu.edu/Resources/papers/P74.pdf