Serpulidae

Key to species of Serpulidae from Hong Kong

1 With operculum...................................................................................... 2

- Without operculum.................................................................................. 21

2(1) Opercular peduncle with wings........................................................................... 3

- Opercular peduncle without wings....................................................................... 9

3(2) Operculum with calcareous end plate....................................................... Spirobranchus … 4

- Operculum with chitinous column bearing several serrated disks........................... Pomatostegus actinoceras

4(3) Collar without chaetae; operculum without projection...................................... Spirobranchus kraussii

- Collar with chaetae; operculum variable................................................................... 5

5(4) Operculum terminated by white calcareous plate or cap...................................................... 6

- Operculum terminated by semi-transparent, almost brown/purplish thinly calcareous cap...... Spirobranchus cf. polytrema

6(5) Operculum with one calcareous plate...................................................................... 7

- Operculum with more than four successive calcareous plates.................................................. 8

7(6) Operculum with a pair of horns............................................. Spirobranchus corniculatus- complex

- Operculum with three branched spines................................................. Spirobranchus tetraceros

8(6) Operculum with four to five calcareous plates and a horn on apex.............................. Spirobranchus sp. A

- Operculum with eight to ten calcareous plates, without horns................................... Spirobranchus sp. B

9(2) Peduncle flattened, ribbon-like.................................................... Metavermilia acanthophora

- Peduncle cylindrical................................................................................. 10

10(9) Opercular peduncle annulated anteriorly............................................... Vermiliopsis glandigerus

- Opercular peduncle smooth, not annulated................................................................ 11

11(10) Operculum complex, with proximal funnel and distal verticil...................................... Hydroides … 12

- Operculum simple funnel..................................................................... Serpula … 20

12(11) Spines of verticil with T-shaped tips...................................................... Hydroides diramphus

- Spines of verticil with acute tips........................................................................ 13

13(12) Verticil spines with external spinules................................................... Hydroides sanctaecrucis

- Verticil spines without external spinules.................................................................. 14

14(13) Verticil spines with lateral spinules..................................................................... 15

- Verticil spines without lateral spinules................................................................... 16

15(14) Verticil spines with one pair of outer lateral spinules in the middle........................ Hydroides tambalagamensis

- Verticil spines with three to four pairs of lateral spinules....................................... Hydroides elegans

16(14) Verticil spines similar in shape and size................................................................... 17

- Verticil spines with one or more spines larger than others.................................................... 18

17(16) Peduncle long, with a long yellowish chitinized constriction; verticil spines six, thin............... Hydroides longistylaris

- Peduncle without a long chitinized constriction; verticil spines five, broad rhomboid............. Hydroides rhombobulus

18(16) Tip of verticil spines blunt................................................................ Hydroides albiceps

- Tip of verticil spines pointed........................................................................... 19

19(18) Smaller spines of verticil curving inward................................................ Hydroides operculatus

- Smaller spines of verticil curving outward.................................................. Hydroides exaltatus

20(11) Opercular funnel deep with long radial grooves; with 33–35 radii.................................. Serpula watsoni

- Opercular funnel shallow; with 55–58 radii............................................... Serpula cf. granulosa

21 (2) Forms open colonies consisting of large number of tiny tubes................................... Salmacina cf. dysteri

- Solitary tubes.......................................................................... Protula bispiralis