Sigambra Muller 1858

Key to species of Sigambra Müller, 1858 (modified after Salazar-Vallejo et al. 2019) 1. Dorsal cirri larger than ventral cirri................................................................................................... 2 – Dorsal and ventral cirri subequal..................................................................................................... 26 2. Chaetiger 2 without ventral cirri........................................................................................................ 3 – Chaetiger 2 with ventral cirri........................................................................................................... 22 3. Pharynx with 8 marginal papillae...................................................................................................... 4 – Pharynx with 13–16 marginal papillae.............................................................................................. 7 4. Dorsal hooks from chaetigers 3–8..................................................................................................... 5 – Dorsal hooks from chaetigers 15–17 (5–18 mm long; up to chaetiger 30?); median and posterior notopodia with 1 capillary; median antenna long, reaching chaetiger 7......... S. vargasi Dean, 1999 5. Median and posterior notopodia with capillaries............................................................................... 6 – Notopodia without capillaries; all neurochaetae with tips entire; median antennae reaching chaetiger 5 (17–23 mm long).................................................... S. papagayu Bamber in Muir & Bamber, 2008 6. Some neurochaetae with bifid tips; median antenna barely longer than laterals, reaching chaetiger 2; median and posterior notopodia with 2 capillaries......... S. bidentata Britayev & Saphronova, 1981 – All neurochaetae with entire tip; median antenna markedly longer than laterals, reaching chaetiger 3; median and posterior notopodia with 1 capillary....... S. qingdaoensis Licher & Westheide, 1997 7. Dorsal hooks from anterior chaetigers (4–18)................................................................................... 8 – Dorsal hooks from median chaetigers (30–40); median antenna twice as long as lateral ones or longer............................................................................................................................................. 21 – Dorsal hooks from posterior chaetigers (42–66), or beyond that (14 mm long); median antenna as long as lateral ones, barely reaching chaetiger 1........................................ S. rugosa Fauchald, 1972 8. Tentacular segment about twice as wide as long............................................................................... 9 – Tentacular segment 4 times as wide as long.....................................................................................11 9. Tentacular segment with anterior margin with rounded projected lobes, external to lateral antennae................................................................................................. Sigambra sp. indet. * (Brazil) – Tentacular segment with anterior margin smooth, without projected lateral lobes; dorsal hooks from chaetiger 3–4 (14 mm long)............................................................................................................. 10 10. Antennae of similar length; dorsal cirri of median segments 5 times as long as wide.............................................................................................................................................. S. setosa Fauchald, 1972 – Median antenna almost twice as long as lateral ones; dorsal cirri of median segments 3 times as long as wide................................................................................ S. phuketensis Licher & Westheide 1997 11. Tentacular segment with rounded projected lobes in anterior margin; median antenna slightly longer than lateral ones, reaching chaetigers 3–4....................................................................................... 12 – Tentacular segment with anterior margin smooth, without rounded projected lobes...................... 13 12. Dorsal hooks from chaetigers 4–5 (6–12 mm long)........................................... S. parva (Day, 1963) – Dorsal hooks from chaetiger 8 (2–9 mm long)......................................... S. sundarbanensis sp. nov. 13. Median and posterior notopodia with capillaries............................................................................. 14 – Notopodia without capillaries.......................................................................................................... 20 14. Median antenna short, reaching up to chaetigers 3–4...................................................................... 15 – Median antenna medium-sized, reaching chaetigers 5–7................................................................ 16 – Median antenna long, reaching chaetigers 9–12; dorsal hooks of chaetigers 11–15 (40 mm long); lateral antennae without lateral depressions.............................................. S. bassi sensu Blake, 1994 15. Dorsal hooks from chaetiger 4 (15 mm long); median antenna slightly longer than lateral ones; first dorsal cirri slightly longer than dorsal tentacular ones.................... S. tentaculata sensu Blake, 1994 – Dorsal hooks from chaetiger 12–18 (16 mm long); median antenna twice as long as lateral ones; first dorsal cirri markedly longer than dorsal tentacular ones.... S. elegans Britayev & Saphronova, 1981 16. Median antenna slightly longer than lateral ones, reaching chaetigers 4–6; dorsal hooks from chaetigers 7–10 (5.5 mm long)........................................... S. pettiboneae Hartmann-Schröder, 1979 – Median antenna twice as long as lateral ones.................................................................................. 17 17. Median antenna reaching chaetigers 7–8......................................................................................... 18 – Median antenna reaching up to chaetigers 5–6; dorsal hooks from chaetigers 4–5........................ 19 18. Dorsal hooks from chaetigers 3–9 (5–20 mm long)............................. S. hanaokai (Kitamori, 1960) – Dorsal hooks from chaetigers 12–18 (24 mm long).................................... S. bassi (Hartman, 1947) 19. All parapodia with ventral cirri shorter than neuropodial lobes; dorsal cirri basally wider......................................................................................................................... S. tentaculata (Treadwell, 1941) – Median and posterior parapodia with ventral cirri long, reaching tip of neuropodial lobes; dorsal cirri tapered, not wider basally............................................................ S. diazi Salazar-Vallejo et al., 2019 20. Median antenna medium-sized, reaching chaetigers 3–4; posterior region with 4–6 hookless chaetigers; body papillae large in proportion................................................... S. grubii Müller, 1858 – Median antenna short, reaching chaetigers 2–3; posterior region with 2 hookless chaetigers; body papillae small.................................................................... S. hernandezi Salazar-Vallejo et al., 2019 21. Median antenna slightly longer than laterals; body without a constriction on chaetiger 4; dorsal hooks from chaetigers 30–39 (15–24 mm long); posterior chaetigers without capillary notochaetae.................................................................................................... S. olivai Salazar-Vallejo et al., 2019 – Median antenna twice as long as laterals; body with a constriction on chaetiger 4; dorsal hooks from chaetiger 30–40 (16–24 mm long); posterior chaetigers with a single capillary notochaetae.......................................................................................................................... S. constricta (Southern, 1921) 22. Pharynx with 8 marginal papillae.................................................................................................... 23 – Pharynx with 14–16 marginal papillae............................................................................................ 25 23. Median antenna slightly longer than lateral ones............................................................................ 24 – Median antenna twice as long as lateral ones; dorsal hooks from chaetigers 26–28........................................................................................................................... S. ligneroi Salazar-Vallejo et al., 2019 24. Dorsal hooks from chaetiger 4 (0.7 mm wide), tentacular segment as long as wide................................................................................................................................................ S. healyae Gagaev, 2008 – Dorsal hooks from chaetigers 23–30 (45–70 mm long); tentacular segment 4–5 times as wide as long............................................................................................................... S. wassi Pettibone, 1966 25. Dorsal hooks from chaetiger 7, with accessory capillaries; dorsal cirri progressively longer from chaetiger 2............................................................................................... Sigambra sp. Imajima, 2001 – Dorsal hooks from chaetigers 43–70, without capillary chaetae; dorsal cirri of chaetiger 2 smaller than those in following chaetigers............................................................... S. robusta (Ehlers, 1908) 26. Dorsal hooks from chaetiger 6 (1.5 mm long)....................... S. ocellata (Hartmann-Schröder, 1959) – Dorsal hooks from chaetiger 3 (3.7 mm long).................. S. magnuncus (Paterson & Glover, 2000) * As per Salazar-Vallejo et al. (2019), this is not completely identified and based upon some specimens which have not been described yet, but are distinct and deserve to be described.Published as part of Bhowmik, Moumita, Ghoshal, Priya, Salazar-Vallejo, Sergio I. & Mandal, Sumit, 2021, Sigambra sundarbanensis sp. nov. (Annelida, Pilargidae) from the Indian sector of Sundarbans Estuarine System, with remarks on parapodial glands, pp. 49-66 in European Journal of Taxonomy 744 on pages 60-62, DOI: 10.5852/ejt.2021.744.1301, http://zenodo.org/record/467146