Scalibregma, Rathke, 1843

Mendes, Samuel Lucas Da Silva Delgado, Rizzo, Alexandra E. & Paiva, Paulo Cesar De, 2023, Unravelling the diversity of Scalibregma Rathke, 1843 (Annelida: ‘ Polychaeta’: Scalibregmatidae) from southeast Brazilian coast, Zootaxa 5353 (5), pp. 441-454 : 452

Key to species of Scalibregma

1 Branchiae present from chaetigers 2–5.................................................................... 2

- Branchiae present from chaetigers 3–5.................................................................... 3

2(1) Lyrate chaetae from chaetiger 2.......................................................................... 4

- Lyrate chaetae from chaetiger 3......................................... S. celticum Mackie, 1991 ( Wales, England)

3(1) Lyrate chaetae with equal tynes....................................................... S. lanai sp. nov. ( Brazil)

- Lyrate chaetae with unequal tynes........................................................................ 7

4(2) Peristomium dorsally uniannulated....................................................................... 5

- Peristomium dorsally biannulated.................................... S. californicum Blake, 2000 (California, USA)

5(4) Mouth’s upper lip biannulated........................................................................... 6

- Mouth’s upper lip uniannulated; mouth’s lower lip biannulated......... S. australis Blake, 2015 (East Antarctica Peninsula)

6(5) Chaetigers 1–3 triannulated; quadriannulated on mid-body, then pentannulated posteriorly; lower lip uniannulated....................................................................... S. inflatum ( Ashworth, 1901) (Molde, Norway)

- Chaetiger 1 triannulated, then quadriannulated from chaetigers 2–5; pentannulated posteriorly; mouth’s lower lip biannulated.............................................................................. S. cynthiae sp. nov. ( Brazil)

7(3) Long and slender frontal horns; up to 14 lyrate chaetae per fascicle.................................................................................................... S. stenocerum ( Bertelsen & Weston, 1980) (Florida, USA)

- Short and digitiform horns; up to 12 lyrate chaetae per fascicle...................................................................................................... S. hanseni Bakken, Oug & Kongsrud, 2014 (Egga, Norway)