Vertical distribution and structure of copepod (Arthropoda: Copepoda) assemblages in two different seasons down to 1,200 m in the tropical Southwestern Atlantic

Abstract

The vertical distribution of copepod assemblages, ascertained from the surface down to 1,200 m, was investigated during two sampling periods (rainy and dry seasons), at four depths, in the oligotrophic waters of the southwestern Atlantic Ocean. Total density, diversity, and richness differed among sampling depths. Copepod density decreased with depth in the two sampling periods, with a maximum at 1 m and a slight decrease at 800 m. Higher diversities were observed at 250 m and 1,200 m during the rainy season and at 1 m and 1,200 m during the dry season. The maximum number of species was found at 1,200 m during the rainy season and at 1 m during the dry season. Various copepod assemblages were delimited in the water column in the two sampling periods. The deeper copepod assemblages occupied a wider range of depths. Salinity and temperature influenced the structure of copepod assemblages and reflected the hydrographic characteristics of the water masses in the region. Candaciapachydactyla (Dana, 1849), Scolecithrixdanae (Lubbock, 1856), and Agetuslimbatus (Brady, 1883) were the indicator species found at 1 m. The effects of different environmental factors on the copepod assemblages suggest that these consortia occupy distinct niches in the ocean.

Responses of Zooplankton Community Pattern to Environmental Factors along the Salinity Gradient in a Seagoing River in Tianjin, China

“…The sampling depth was more important for the mesozooplankton community than the spatial distribution of the sampling stations, in spite of the large geographic extent of the study area [ 25 ]. The negative relationship between WD and copepods was consistent with a study in the tropical Southwestern Atlantic [ 26 ]. As a previous study reported, depth was likely one of the primary abiotic factors influencing the zooplankton distributions [ 27 ].…”

Proteomic fingerprinting facilitates biodiversity assessments in understudied ecosystems: A case study on integrated taxonomy of deep sea copepods

“…This database includes 15 obligate benthopelagic species described in recent years from abyssal depth. In a study off the Brazilian Coast, Dias et al, (2018) detected 111 species of calanoids from 44 genera down to 1,200 m depth. The present study revealed one of the highest species numbers detected so far for the benthopelagic layers of the abyssal deep sea in the South Atlantic.…”