Paraprionospio (Caullery, 1914)

Delgado-Blas, Víctor H. & Carrera-Parra, Luis F., 2018, New Phylogenetic Analysis of Paraprionospio Caullery (Polychaeta: Spionidae), with Description of a New Species from the Gulf of Mexico, Zoological Studies 57 (52), pp. 1-20 : 19

Taxonomic key to all Paraprionospio species

1. A filament present at base of third branchia ................. 2

- A filament absent at base of third branchia .................. 9

2(1) With two pairs of branchiae; peristomium with small lateral wings; anterior notochaetae capillary alimbate ..... ............... ..................................... P. dibranchiata sp. nov.

- With three pairs of branchiae; peristomium with big or moderate lateral wings; anterior notochaetae capillary uni- or bilimbate ............................................................ 3

3(2) Interparapodial pouches present .................................. 4

- Interparapodial pouches absent ................................... 7

4(3) Dorsal crests present on postbranchial segments........ 5

- Dorsal crests absent ..................................................... 6

5(4) Small papilla on posterior margin of peristomial wing absent; anterior neuropodial postchaetal lamellae on chaetigers 3-4 rounded; anterior notochaetae capillary unilimbate ............... P. inaequibranchia ( Caullery, 1914)

- Small papilla on posterior margin of peristomial wing present; anterior neuropodial postchaetal lamellae on chaetigers 3-4 triangular; anterior notochaetae capillary bilimbate .................... P. lamellibranchia Hartman, 1974

6(4) Ventral crest present; small papilla on posterior margin of peristomial wing absent; anterior notopodial postchaetal lamellae on chaetigers 1-3 triangular .............................. ............... ............................ P. cordifolia Yokoyama, 2007

- Ventral crest absent; small papilla on posterior margin of peristomial wing present; anterior notopodial postchaetal lamellae on chaetigers 1-3 foliaceous, distally pointed ... ............... ........................ P. oceanensis Yokoyama, 2007

7(3) With small papilla on posterior margin of peristomial wing ..................................... P. patiens Yokoyama, 2007

- Without papilla on posterior margin of peristomial wing 8

8(7) Ventral crest present; ridge between branchial base on chaetigers 2-3 absent; notopodial lamella on chaetigers 1-3 triangular, on chaetiger 4 rounded; neuropodial lamellae on chaetigers 3-4 rounded ................................ ............... .......... P. cristata Zhou, Yokoyama and Li, 2008

- Ventral crest absent; ridge between branchial bases of chaetigers 2-3 present; notopodial lamellae on chaetiger 1 elongate subtriangular, on chaetigers 2-4 foliaceous; neuropodial lamellae on chaetiger 3 triangular, cordate on chaetiger 4 ..................... P. africana ( Augener, 1918)

9(1) Interparapodial pouches present; with small papilla on posterior margin of peristomial wing; dorsal crests absent .......................................... P. coora Wilson, 1990

- Interparapodial pouches absent; without papilla on posterior margin of peristomial wing; dorsal crests present on postbranchial segments............................ 10

10(9) Prostomium peaks present; peristomium small; middle and posterior notopodial postchaetal lamellae rounded; hooks without secondary hood .............. .......................... ............... ............................ P. treadwelli ( Hartman, 1951)

- Prostomium peaks absent; peristomium large; middle and posterior notopodial postchaetal lamellae triangular or cirriform; hooks with secondary hood ..................... 11

11(10) Peristomium with large lateral wings almost enclosing all the prostomium; anterior neuropodial postchaetal lamellae on chaetiger 3 triangular, on chaetigers 4-6 reniform; notopodial prechaetal lamellae basally fused with notopodial postchaetal lamellae on anterior chaetigers .................................... P. alata ( Moore, 1923)

- Peristomium with lateral wings of moderate size, never enclosing prostomium; anterior neuropodial postchaetal lamellae on chaetiger 3 rounded or cordate, on chaetigers 4-6 rounded; notopodial prechaetal lamellae not fused with notopodial postchaetal lamellae on anterior chaetigers ...................................................... 12

12(11) Anterior notopodial postchaetal lamellae on chaetigers 1-2 oval, on chaetigers 4-6 reniform; all hooks with 3 pairs and a single medial tooth at distal end ................... ............... ............................ P. tamaii Delgado-Blas, 2004

- Anterior notopodial postchaetal lamellae on chaetigers 1-2 triangular, on chaetigers 4-6 triangular or subtriangular; hooks with 3-4 pairs, without a single medial tooth ................................................................ 13

13(12) Dorsal crests absent; anterior neuropodial postchaetal lamellae on chaetigers 2-3 rounded ................................ ............... .................................. P. pinnata ( Ehlers, 1901)

- Dorsal crests present; anterior neuropodial postchaetal lamellae on chaetiger 2 triangular, cordate on chaetiger 3................................ P. yokoyamai Delgado-Blas, 2004