Chaetacanthus Seidler, 1924

Salazar-Silva, Patricia, López-Sánchez, Daniel A. & Salazar-Vallejo, Sergio I., 2020, Revision of Chaetacanthus Seidler, 1922 (Annelida, Phyllodocida, Polynoidae), Zootaxa 4885 (3), pp. 395-422 : 417

Key to species of Chaetacanthus Seidler, 1924

1 Elytra of middle and posterior segments with large, amber macrotubercles packed in a sclerotized honeycomb group...... 2

– Elytra of middle and posterior segments without honeycomb group amber macrotubercles........................... 3

2(1) Prostomial anterior eyes area bulky; sclerotized macrotubercles of honeycomb group globular, surface with minute spines; macrotubercles of outer area blunt, fusiform, without acute mucrons.. .................. C. ornatus n. sp. Eastern Pacific

– Prostomial anterior eyes area non-bulky laterally; sclerotized macrotubercles like honeycomb depressed, surface without minute spines; macrotubercles of outer area fusiform, with acute mucrons................................................................... C. brasiliensis ( de Quatrefages, 1866) n. comb. Grand Caribbean to Ubatuba, S„o Paulo, Brazil

3(1) Branchial filaments single, thick lobes ..................................................................... 4

– Branchial filaments bifurcated; elytra with pedunculated microtubercles and macrotubercles hemispherical............................................................................. .. C. pilosus ( Treadwell, 1937) Eastern Pacific

4(3) Elytra of middle and posterior segments with conical macrotubercles (up to five times longer than wide, basally spinous, long tip); microtubercles round and spinous............................ C. pomareae ( Kinberg, 1856) South Central Pacific

– Elytra of middle and posterior segments with globular macrotubercles; microtubercles globular with long tips. ..................................................................................... C. harrisae n. sp. Eastern Pacific