Dardanus sanguinolentus (Quoy & Gaimard 1824)
Fig. 4e
Material.
1 female, SL 2.5 mm and 1 male, SL 2.1 mm (UF 7444), Aguijan Island, station AGU-02 ; 1 female, SL 4.7 mm (SIO-BIC C14507), Saipan Island, station AKM-SAI-01 ; 1 male, SL 4.1 mm (SIO-BIC C14510), Guguan Island, station AKM-GUG-05 .
Remarks. The specimens fit well with the redescription of D. sanguinolentus provided in Malay et al. (2018). Dardanus sanguinolentus was recently resurrected and differentiated from Dardanus lagopodes . In the field, the two are readily distinguished: D. sanguinolentus has a bright red patch on the merus and carpus of the second and third pereopods and D. lagopodes has black patches on the same area, however the color changes to red in preservative. The two species also differ in the sculpturing of the left third pereopod: D. sanguinolentus always has a sulcus on the lateral face of the propodus and dactyl of the left third pereopod. The lateral face of the propodus and dactyl of the left third pereopod of D. lagopodes is more variable: it may be smooth, slender, and completely cylindrical or flattened and spiny, but it never bears a sulcus.