KEY TO SPECIES OF PHERECARDITES HORST, 1912 (modified after bleeker et al. 2023, references therein, type localities after the species name)

1. Prostomium with well-defined, with margins distinct; first branchiae with 3 or more filaments ................... 2

— Prostomium with ill-defined eyes, margins indistinct; first branchiae with 1-2 filaments ................................ ...................................................................................................................... P. parva Horst, 1912 Indonesia

2. Branchiae of median segments with 15-20 filaments; dorsum without pigmented pattern .............................. .................................................................................................. P. antarctica (Hartman, 1967) Antarctic seas

— Branchiae of median segments with 4-12 filaments; dorsum pigmentation variable ..................................... 3

3. Dorsum pale ................................................................................................................................................ 4

— Body dorsally pigmentated; eyes separate, not coalescent ............................................................................. 5

4. Eyes separate, anterior eyes 2-3 times as large as posterior ones ....................................................................... ............................................................................................ P. monroi nom. n. Macclesfield Bank, China Sea

— Eyes nearly coalescent, 8-shaped .................................................... P. islandica (Detinova, 1968) NE Atlantic

5. Branchiae in median segments with 4-8 filaments ....................................................................................... 6

— Branchiae in median segments with about 12 filaments; dorsal pigmentation includes 5 dark elongate spots, three dorsal and two interramal ........................................... P. quinquemaculata Augener, 1927 New Zealand

6. Venter of first four chaetigers pigmented, following segments pale ................................................................. ................................................................................................... P. kohtsukai (Jimi in Jimi et al., 2021) Japan

— Venter with similar pigmentation throughout body ........................................................................................ ...................................................................... P. tropicalis (Barroso, Ranauro & Kudenov, 2017) SW Atlantic