Spionidae

Radashevsky, Vasily I., 2015, Spionidae (Annelida) from Lizard Island, Great Barrier Reef, Australia: the genera Aonides, Dipolydora, Polydorella, Prionospio, Pseudopolydora, Rhynchospio, and Tripolydora, Zootaxa 4019 (1), pp. 635-694 : 637-638

Key to genera of Spionidae reported from or likely to be found on the Great Barrier Reef

1. Branchiae absent. Neuropodia of chaetiger 1 with large crook-like spines in addition to capillaries.......... Spiophanes

– Branchiae present (except some Polydorella ). Neuropodia of chaetiger 1 with only capillaries...................... 2

2. (1) Chaetiger 5 with only capillaries...................................................................... 3

– Chaetiger 5 with heavy spines in addition to capillaries................................................... 11

3. (2) Branchiae throughout most of body length.............................................................. 4

– Branchiae limited to anterior half of body............................................................... 9

4. (3) Head anteriorly conical and distally pointed............................................................. 5

– Head anteriorly wide, truncate to conical but not distally pointed............................................. 6

5. (4) Dorsal branchiae from chaetiger 1. Lateral branchiae on posterior face of notopodia. Chaetiger 1 notopodial capillaries much longer than on succeeding chaetigers. Posterior notopodia with only capillaries........................ Dispio

– Dorsal branchiae from chaetiger 2. Lateral branchiae absent. Chaetiger 1 notopodial capillaries same or shorter than on succeeding chaetigers. Posterior notopodia with hooks and capillaries.................................. Scolelepis

6. (4) Prostomium greatly expanded anteriorly, T-shaped or with fronto-lateral horns. Pygidium with two or more pairs of cirri 7

– Prostomium narrow to slightly expanded anteriorly, without fronto-lateral horns. Pygidium with two pairs of cirri...... 8

7. (6) Branchiae from chaetiger 1. Nuchal organs entire............................................... Malacoceros

– Branchiae from chaetiger 2. Nuchal organs metameric............................................ Rhynchospio

8. (6) Branchiae from chaetiger 1. Nuchal segmental metamers double pairs each composed of two halves of an oval structure separated anteriorly and posteriorly by narrow gaps.................................................... Spio

– Branchiae from chaetiger 2. Nuchal segmental metamers single pairs of crescents or straight bands on a segment................................................................................................ Microspio

9. (3) Occipital antenna present. Nuchal organs extending beyond chaetiger 4. Branchiae over most of anterior body.. Laonice

– Occipital antenna present or absent. Nuchal organs over 1–4 anterior chaetigers or absent. Branchiae limited to first 20 chaetigers....................................................................................... 10

10. (9) Prostomium conical with narrow and rounded tip anteriorly. Occipital antenna present or absent. Nuchal organs absent............................................................................................. Aonides

– Prostomium broadly rounded to truncate anteriorly (fronto-lateral horns present in P. cerastae n. sp.). Occipital antenna absent. Nuchal organs U-shaped over 1–4 chaetigers.............................................. Prionospio

11. (2) Living in silty tubes on sponge surface. Body short, with constant number of chaetigers, up to 16. Branchiae one or two pairs, or entirely absent. Asexual reproduction by paratomy........................................ Polydorella

– Living otherwise. Body long, with lifelong increasing number of chaetigers, more than 16. Branchiae more than two pairs. Asexual reproduction by architomy, if present........................................................... 12

12. (11) Hooks tridentate, in neuropodia from chaetiger 9................................................ Tripolydora

– Hooks bidentate, in neuropodia from chaetiger 7 or 8..................................................... 13

13. (12) Hooks in neuropodia from chaetiger 8; upper part of hook shaft with constriction, lower part of hook shaft bent at about right angle. Branchiae from chaetiger 7..................................................... Pseudopolydora

– Hooks in neuropodia from chaetiger 7; upper part of hook shaft with or without constriction, lower part of hook shaft slightly curved. Branchiae from chaetigers 2–10......................................................... 14

14. (13) Branchiae from chaetiger 2 (from chaetiger 7 in early juveniles)............................................ 15

– Branchiae from chaetigers 7–10 in all-size individuals.................................................... 16

15. (14) Notopodia of chaetiger 5 with heavy falcate spines alternating with bilimbate-tipped companion chaetae.... Boccardiella

– Notopodia of chaetiger 5 with heavy falcate spines and brush-topped spines............................. Boccardia

16. (14) Chaetiger 1 with notochaetae. Branchiae from chaetigers 7–10. Hooks accompanied by inferior capillaries at least in ante- rior neuropodia; upper part of hook shaft without constriction....................................... Dipolydora

– Chaetiger 1 without notochaetae. Branchiae from chaetiger 7. Hooks not accompanied by inferior capillaries; upper part of hook shaft with constriction................................................................... Polydora