Thaliacean community responses to distinct thermohaline and circulation patterns in the Western Tropical South Atlantic Ocean

In western boundary current systems, strong currents transport oligotrophic oceanic waters towards the coast. Thaliaceans may have an advantage in these systems due their ability to filter small particles such as bacterioplankton, typically responsible for primary production waters. Here, we evaluated structure of thaliacean community present tropical South Atlantic Ocean system test hypothesis that species distribution and abundance are structured by circulation thermohaline features. For purpose, used data collected though 40 mm mesopelagic trawls above slope around seamounts islands. Results reveal distinct patterns structure. Over continental slope, under influence North Brazilian Undercurrent, Pyrosoma atlanticum was highly abundant. Soestia zonaria also but a lesser amount. Offshore, islands Seamounts central branch Equatorial Current, Doliolida spp. were dominant thaliacean, co-occurring with P. lower abundance. Mesh selectivity is potential drawback results since coarse aperture lost smaller early life stages.