Prionospio Malmgren, 1867

Hektoen, Martin M., Radashevsky, Vasily I. & Bakken, Torkild, 2025, Partial revision of northern European Prionospio Malmgren, 1867 (Annelida: Spionidae), European Journal of Taxonomy 1027, pp. 1-58 : 52

Identification key to the species of adult Prionospio Malmgren, 1867 i n Northern Europe

1. At least some branchiae with pinnules ............................................................................................. 2

– All branchiae apinnate ...................................................................................................................... 6

2. Pinnate branchiae on chaetigers 2, 3 and 5, pinnules on branchiae of chaetiger 3 may only be present basally .................................................................... Prionospio plumosa M. Sars in G.O. Sars, 1872

– Pinnate branchiae otherwise ............................................................................................................. 3

3. Dorsal crests absent ...................................... Prionospio multisetosa Delgado-Blas & Peraza, 2024

– Dorsal crests present ......................................................................................................................... 4

4. High dorsal crest present on chaetiger 7 only ........................... Prionospio fallax Söderström, 1920

– Dorsal crests present on more than one chaetiger ............................................................................ 5

5. Dorsal crests from chaetiger 6, membranous folds between successive notopodia on some chaetigers between chaetigers 4 and 17 ............................................... Prionospio steenstrupi Malmgren, 1867

– Dorsal crests from chaetiger 7, membranous folds between successive notopodia absent ................. ................................................................................................... Prionospio sigvaldadottirae sp. nov.

6. One pair of branchiae on chaetiger 3 ........................................................................ Prionospio sp. 6

– More than one pair of branchiae ....................................................................................................... 7

7. 2–5 pairs of branchiae from chaetiger 2 or 3 (usually three pairs of branchiae from chaetiger 3). Low dorsal crests from chaetiger 6–9 ............................................ Prionospio banyulensis Laubier, 1966

– At least five pairs of branchiae from chaetiger 2. Dorsal crests from chaetiger 10 or later ............. 8

8. Up to six pairs of branchiae. Prostomium extending to end of chaetiger 2. Lower part of neuropodial postchaetal lamellae of chaetiger 2 elongated and pointed downwards ............................................. ................................................................................................ Prionospio cirrifera Wirén, 1883 agg.

– Up to 13 pairs of branchiae. Prostomium extending at the most to the middle of chaetiger 2. Lower part of neuropodial postchaetal lamellae of chaetiger 2 rounded ..................................................... 9

9. Prostomium anteriorly rounded, narrow caruncle extending to middle of chaetiger 2. Median eyes small or large .............................. Prionospio sanmartini Delgado-Blas, Díaz-Díaz & Viéitez, 2019

– Prostomium triangular, anteriorly truncate, thick caruncle extending to end of chaetiger 1. Eyes indistinct in all individuals ..................................................................... Prionospio fiordica sp. nov.