Genus Pseudopolydora Czerniavsky, 1881

Pseudopolydora Czerniavsky, 1881: 362 .

Carazzia Mesnil, 1896: 227 .

Polydora (Carazzia) – Fauvel 1927: 48; 1953: 316.

Polydora (Pseudopolydora) – Hartmann-Schröder 1971: 317; 1996: 322.

Pseudopolydora – Fauchald 1977: 25. — Blake & Kudenov 1978: 267. — Blake 1996: 202. — Blake et al. 2020: 79−80.

List of species of Pseudopolydora from the Arabian Gulf and their type localities

Pseudopolydora achaeta Radashevsky & Hsieh, 2000, South China Sea, Taiwan.

Pseudopolydora antennata (Claparède, 1868) . Tyrrhenian Sea, Gulf of Naples, Italy.

Pseudopolydora arabica Radashevsky & Al-Kandari, 2020 . Arabian Gulf, Al-Salmiya, Kuwait.

Pseudopolydora auha sp. nov. Arabian Gulf, Auha Is., Kuwait.

Pseudopolydora kuwaiti sp. nov. Arabian Gulf, Al-Judailiat, Kuwait.

Pseudopolydora melanopalpa sp. nov. Arabian Gulf, Sulaibikhat Bay, Kuwait.

Pseudopolydora multispinosa sp. nov. Arabian Gulf, Al-Salmiya, Kuwait.

Identification key to Pseudopolydora from the Arabian Gulf

1. Chaetiger 5 distinctly larger than chaetiger 4. Chaetiger 5 spines arranged in a curved diagonal double row. Occipital antenna absent. Yellow bands regularly arranged on palps (invisible after fixation). Caruncle to end of chaetiger 2. Tube-dwelling or shell-boring ............ P. kuwaiti sp. nov.

– Chaetiger 5 same in size as chaetiger 4. Chaetiger 5 spines arranged in a slightly curved, J- or U-shaped vertical double row. Occipital antenna present. Yellowish chromatophores present or absent on palps in live. Caruncle to end of chaetiger 2 or longer. Tube-dwelling ............................ 2

2. Chaetiger 5 spines arranged in a straight or slightly curved vertical double row. Caruncle to end of chaetiger 2. Black pigment present on dorsal side of 10−15 anterior chaetigers ............................... ............................................................................................. P. achaeta Radashevsky & Hsieh, 2000

– Chaetiger 5 spines arranged in a J- or U-shaped vertical double row. Caruncle extending beyond chaetiger 2. Black pigment absent on dorsal side of anterior chaetigers .......................................... 3

3. Prostomium anteriorly entire, rounded. Chaetiger 5 spines arranged in a J-shaped double row. Yellowish chromatophores regularly arranged on palps (invisible after fixation). Caruncle to end of chaetiger 4. Pygidium disc-like to cup-shaped with only dorsal gap ................................................. ...................................................................................... P. arabica Radashevsky & Al-Kandari, 2020

– Prostomium anteriorly incised to bifurcated. Chaetiger 5 spines arranged in a U-shaped double row. Yellowish chromatophores absent on palps. Caruncle to end of chaetiger 4 or longer. Pygidium bilobed with dorsal and ventral clefts ............................................................................................... 4

4. Fine black pigment scattered on distal end of palps. Prostomium anteriorly incised, with two rounded lobes ............................................................................................................. P. melanopalpa sp. nov.

– No pigmentation on palps. Prostomium with two rounded lobes or long pointed antero-lateral processes ........................................................................................................................................... 5

5. Chaetiger 5 with up to 32 spines in the outer (anterior) row of notochaetae, and 27 spines in the inner (posterior) row of notochaetae; notopodial postchaetal lamellae same as on chaetiger 4 or 6. MG staining of formalin-fixed specimens drastically intense on ventral side from chaetiger 8 onwards. Notopodial anterior-row spines of chaetiger 5 with distal part of stem curved, gradually narrowing, with wide, distally pointed limbation .......................................................... P. multispinosa sp. nov.

– Chaetiger 5 with fewer spines in notopodia; notopodial postchaetal lamellae reduced. MG staining on ventral side of formalin-fixed specimens comparatively weak, gradually changing along body. Notopodial anterior-row spines of chaetiger 5 with distal part of stem enlarged, with concavity on top and large triangular tooth on its side directed upwards; fine bristles arising from concavity forming long flag-like pointed geniculate transparent tip ................................................................ 6

6. Caruncle to end of chaetiger 4 ......................................................... P. antennata (Claparède, 1868)

– Caruncle to end of chaetiger 6 .................................................................................. P. auha sp. nov.