Cherusius triunguiculatus (Borradaile, 1902)

(Fig. 1 A)

Material examined. 1 male (4.7 mm × 3.7 mm), 1 female (6.1 mm × 4.6 mm), Piko, Easter Island, coll. C. B. Boyko & S. Reanier, 31 August 1999 (ZRC 2016.0121) .

Geographical distribution. Indo-West Pacific and Tropical Eastern Pacific regions (Castro 2011).

Remarks. Low & Ng (2012) introduced Cherusius as a replacement name for the preoccupied Jonesius Sankarankutty, 1962 . This is the first record of the species from Easter Island. It is considered an obligate symbiont of scleractinian corals (Castro 2015).