A new Ingolfiellid amphipod crustacean from sandy beaches of the Gura Ici islands, Western Halmahera (North Moluccas)

Ingolfiella moluccensis, a new species of ingolfiellid amphipod (Ingolfiellidae), is described from coarse coral sands of the Gura Ici islands (northern Moluccas; Indonesia). The species is unique among ingolfiellideans in the display of a rounded outgrowth on the proximo-lateral margin of basis of P5, and of a sexually-dimorphic, modified medial margin of coxa in the same limb. Other features point to close affinities with a group of seven insular species that show a broad but punctuated distribution along the Atlantic and SW Pacific oceans. These species share the combined display of four denticles on the posterior margin of dactylus of G1 & G2; three comb rows of denticles on the medial margin of the protopod of U2; a trifid unguis of P3-P4; and a bifid unguis of P5-P7. The placement of ingolfiellideans among the amphipods is briefly discussed in relation to current analyses. An overview of all species of Ingolfiella within a comparison of 12 characters is provided, including the eight new species described since 2003.