Description, distribution and ecology of living Reophax pyriformis n. sp. (Campos Basin, South Atlantic Ocean)

TL;DR

This study describes the distribution, ecology, and environmental associations of a newly identified benthic foraminiferal species, Reophax pyriformis, in the Campos Basin, highlighting its relation to organic matter and lipid biomarkers at specific depths.

Contribution

It provides the first detailed account of Reophax pyriformis distribution, ecology, and its environmental correlations in the South Atlantic Ocean.

Findings

Found at 1,000-1,200 m water depth

Distribution linked to lipid biomarkers and organic carbon

Average living depth in sediment is 1.52 cm

Abstract

The distribution of living (rose Bengal stained) Reophax pyriformis Yamashita, Sousa and Kaminski, n. sp., an agglutinated benthic foraminiferal species, was analyzed in the area of the Campos Basin (southeastern Brazilian continental margin). The study is based on 34 oceanographic stations (54 samples), located between 400 m and 3,000 m water depth. The distribution of living Reophax pyriformis n.sp. density is compared to sedimentological parameters, such as total organic carbon, total nitrogen, calcium carbonate, phytopigment, lipids biomarkers (sterols, fatty acids and n-alcohols), total lipids, and bacterial biomass, as well as the particulate organic matter flux to the seafloor. This species was found in the range of 1,000--1,200 m water depth, with an average living depth of 1.52 cm in the sediment. The distribution of this species seems to be related to lipid biomarkers (allochthone and/or continental derivative, zooplankton and/or fauna, phytoplankton or primary producers) and total organic carbon under the influence of Intermediate Western Boundary Current conditions.