A taxonomic and distributional survey of marine benthonic Ostracoda off Kerguelen and Heard Islands, South Indian Ocean

Abstract

-From an examination of 34 grab and dredge samples ranging from 110 m to 3584 m water depth, collected during Eltanin cruise 47 across the Kerguelen Plateau, 26 shallow-water and 35 deep-sea benthonic ostracod species have been identified. Systematic notes and illustrations of the common and some of the rare species are presented. Two new species are described: Philoneptunus cassidyi n. sp. and Taracythere abyssora n. sp. Comparisons made with the Atlantic and SW Pacific Oceans and circumAntarctic regions indicate that the fauna comprises dominantly cosmopolitan deep-sea species while most of the other species have close affinities with the SW Pacific. In the Kerguelen material, seven distinct depth assemblages appear to correspond well with differing watermasses and there is evidence that the relatively shallow position of Antarctic Intermediate Water permits elevation of the upper depth limits of some deep-sea species. Some species have developed ornament of fine reticulation, features not previously seen in those species outside the Kerguelen region.

Glacial–interglacial variability in deep sea ostracod assemblage composition at IODP Site U1314 in the subpolar North Atlantic

“…Species of Krithe have different depth distributions ranging from b500 to N5000 m (Rodriguez-Lázaro and , but previous studies have shown that the genus is mainly associated with cold water masses (Coles et al, 1994;Cronin et al, 1994Cronin et al, , 1999Whatley et al, 1996;Ayress et al, 1997;Rodriguez-Lázaro and Cronin, 1999;Ayress et al, 2004). Instances when Krithe is found living in relatively shallow water are usually in high-latitude seas, the Arctic Ocean (Cronin et al, 1994Whatley et al, 1998), in very cold AAIW off the Kerguelen Plateau, South Indian Ocean (Ayress et al, 1997) and/or in areas of coastal upwelling (Rodriguez-Lázaro and .…”

“…Some species are restricted to shallow subpolar shelves, others inhabit the upper continental slope and Central Arctic Ocean (Whatley and Masson, 1979;Brouwers, 1994;Cronin et al, 1995;Whatley et al, 1996Whatley et al, , 1998Ayress et al, 2004;Stepanova et al, 2004;Stepanova, 2006). Cytheropteron species from the Arctic Ocean are usually found in the deep North Atlantic, N1000 m (Whatley and Coles, 1987;Dingle and Lord, 1990;Van Harten, 1990;Cronin et al, 1996Cronin et al, , 1999.…”

“…Detailed investigations of modern and recent regional distribution of ostracod species from shelf, slope, bathyal and abyssal environments indicate that their distribution is strongly influenced by the water mass physico-chemical (e.g., temperature, salinity, nutrients, dissolved oxygen, etc) and substrate characteristics (Benson Marine Geology 258 (2009) 69-87 et al, 1983;Dingle et al, 1989;Dingle and Lord, 1990;Corrège 1993;Cronin et al, 1994Cronin et al, , 1995Ayress et al, 1997;Whatley et al, 1998;Cronin et al, 2002;Ayress et al, 2004).…”

The Lower Miocene cytherellids (Crustacea, Ostracoda) from the Pelotas Basin and their significance for the South Atlantic Paleozoogeography

“…Though the wide temporal range ascribed to those two species (Oligocene to Recent) might be questionable (see discussion in Bergue et al, 2013) the data provided by Yasuhara and colleagues support that the circum-Antarctic dispersion had already been stablished at least in the Neogene, even before the complete opening of the Drake Passage. Ayress et al (2004) also proposed that the Southern Ocean and its ACC are responsible for the establishment of dispersion routes for ostracodes. Based on the paleobathymetric interpretation by Gomide (1989) of the deposits here studied (outer shelf/ upper slope) they are in accordance to the bathymetric preferences of other species of Inversacytherella, such as I. tanantia and I. pleistocenica, which were also described in deep waters.…”

The lower Eocene-lower Oligocene ostracodes from DSDP Site 515B, Brazil Basin, Southwestern Atlantic Ocean

“…Ocean circulation and hydrologic changes, productivity and sedimentary processes are examples of research fi elds that have benefi ted from the study of ostracodes (Cronin, 1983;Ayress et al, 2004;Yasuhara & Cronin, 2008).…”