Sigambra Muller 1858

Key to Sigambra Müller, 1858 from the Indo-Pacific region (modified after Bhowmik et al. 2021) 1. Chaetiger 2 lacking ventral cirri; pharynx with 8 marginal papillae............................................... 2 – Chaetiger 2 lacking ventral cirri; pharynx with 12–14 marginal papillae.......................................... 4 2. Some neurochaetae with bifid tips; dorsal hooks from chaetigers 3–5; median and posterior notopodia with 2 capillaries per parapodia.................................. S. bidentata Britaev & Saphronova, 1981 (Sea of Japan, Pacific Ocean) – Neurochaetae lacking bifid tips; dorsal hooks from chaetigers 3–7............................................... 3 3. Median antenna reaching to chaetiger 5; notopodia without capillaries, dorsal hooks from chaetigers 3–5..................................................................... S. papagayu Bamber in Muir & Bamber, 2008 (Hong Kong) – Median antenna 2 times longer than lateral antennae; notopodia with capillaries; dorsal hooks from chaetigers 3–8........................................................ S. qingdaoensis Licher & Westheide, 1997 (China, Pacific Ocean) 4. First dorsal hooks from anterior chaetigers................................................................. 5 – First dorsal hooks from median chaetigers................................................................ 10 5. First dorsal hooks from chaetigers 3–10................................................................... 6 – First dorsal hooks from chaetigers 12–18; pharynx with 13 marginal papillae................................................................................... S. elegans Britaev & Saphronova, 1981 (Sea of Japan, Pacific Ocean) 6. Median antenna longer than lateral antennae; pharynx with 14 marginal papillae................................... 7 – Median antenna slightly longer than lateral antennae, pharynx with 13 marginal papillae; first dorsal hooks from chaetigers 7–10............................................... S. pettiboneae Hartmann-Schröder, 1979 (Western Australia) 7. First dorsal hooks from chaetiger 3–4; notopodia with capillaries............................................... 8 – First dorsal hooks from chaetiger 8....................................................................... 9 8. First dorsal hooks from chaetiger 3.................. S. phuketensis Licher & Westheide, 1997 (Andaman Sea, Thailand) – First dorsal hooks at chaetiger 4.................................. S. hanaokai Kitamori, 1960 (Japan, Pacific Ocean) 9. Notopodia with capillaries..................................... S. pakbaraensis sp. nov. (Andaman coast, Thailand) – Notopodia without capillaries........................................................................................ S. sundarbanensis Bhowmik, Ghoshal, Salazar-Vallejo & Mandal, 2021 (River Thakuran, Sundarbans, E India) 10. Median antenna long as 3–5 times of lateral antennae, notopodial capillaries present from anterior chaetigers; pharynx with 12 marginal papillae....................................................... S. sirilukae sp. nov. (Gulf of Thailand) – Median antenna nearly 2 times longer than lateral antennae; notopodial capillaries present from posterior chaetigers; pharynx with 14 marginal papillae....................................... S. constricta Southern, 1921 (Chilka Lake, India)