Picoeukaryote diversity in coastal waters of the Pacific Ocean

Concentrations of ten trace elements at five localities in New South Wales coastal waters were measured by ultratrace sampling and analysis. Mean concentrations of cadmium (2.4 ng L-1), copper (31 ng L-1), nickel (180 ng L-1), lead (9 ng L-1) and zinc (<22 ng L-1) are among the lowest reported in the Southern Hemisphere and are consistent with recent oceanographic data for the surface waters of the Pacific Ocean. Waters from the southernmost sampling locality (Eden) contained higher phosphate, silicate, cadmium and nickel, but lower chromium concentrations than waters from the other four localities, reflecting the inputs of water from the Tasman Sea in the south compared with the dominance of waters from the Coral Sea along the rest of the coast. Cadmium concentrations were positively correlated with both phosphate and silicate. Chromium and lead concentrations were also significantly correlated. It is likely that a major source of lead is atmospheric deposition. The trace metal concentrations were comparable to those in the surface waters of the Pacific Ocean, indicating that fluvial inputs or processes occurring in the coastal margin were of limited importance in determining trace metal concentrations.

Download Full-text

A new species of Metaruncina (Gastropoda: Heterobranchia: Runcinida) from Vietnam with a discussion on the so-called rudimentary radula in runcinids

Zootaxa ◽

10.11646/zootaxa.4974.1.12 ◽

2021 ◽

Vol 4974 (1) ◽

pp. 197-200

Author(s):

ALEXEI V. CHERNYSHEV

Keyword(s):

New Species ◽

Pacific Ocean ◽

Coastal Waters ◽

Marine Biology ◽

Pacific Coast ◽

Common Species ◽

Scientific Center ◽

The Pacific ◽

The Pacific Ocean ◽

A New Species

Marine heterobranch slugs of the order Runcinida comprise 61 species, most of which inhabit the Atlantic Ocean and are referred to the genus Runcina. The Runcinida of the Pacific Ocean have been much less studied to date: only 12 species, from the genera Metaruncina Baba, 1967, Rfemsia Chernyshev, 1999, Runcinida Burn, 1963, Runcinella Odhner, 1924, Pseudoilbia M. C. Miller & Rudman, 1968, and Runcina Forbes [in Forbes and Hanley], 1851, have been described from the region. Metaruncina, Rfemsia, and Runcinida are found in the Pacific Ocean only (Baba 1954, 1967; Burn 1963; Gosliner 1991; Chernyshev 1998, 1999, 2005, 2006). The genus Metaruncina, endemic from the Pacific coast of Asia, includes two species: M. setoensis (Baba, 1954) and M. nhatrangensis Chernyshev, 2005. The latter is the only runcinid described from the coastal waters of the South China Sea, where it was found in the bays of Nha Trang and Van Phong (Chernyshev 2005). During subsequent expeditions to the coastal waters of Vietnam, this species was also recorded from off Tho Chu Island (09°19’N, 103°30’E) and off Nam Du Island (09°43′ N, 104°23′ E). However, in addition to this common species, an undescribed species of Metaruncina was collected. A description of this new species is provided in the present paper. Type material was deposited at the Museum of the A.V. Zhirmunsky National Scientific Center of Marine Biology FEB RAS, Vladivostok, Russia (MIMB).

Download Full-text