A brief look at the free-living Nematoda of the oxic/anoxic interface with a new genus record (Trefusia) for the Black Sea

Abstract

In order to provide the first comparative source of nematofaunal data at the oxic/anoxic interface off the Sinop Peninsula, the southern Black Sea, a survey of meiofauna and nematode fauna was conducted in August 2011 aboard the exploration vessel (E/V) Nautilus with ROV during the Black Sea Expedition NA012. Higher meiofaunal taxa and nematode composition were investigated. Free-living marine nematodes were the most abundant group at each site. A total of 84 species were found, belonging to 23 families. The suboxic zone was dominated by the nematode Trefusia aff. longicauda (42%). This is the first record of the genus Trefusia De Man, 1893 for the Black Sea. Although many factors are likely to influence the changes in the meiofaunal abundance and the composition of nematode assemblages, we suggest that oxygen reduction indeed affected the meiofaunal abundance and the nematode composition, however, a particular preference of several taxa for extreme conditions may be suggested.

MICOLETZKYIA LONGISPICULA HUANG & CHENG, 2011 (NEMATODA: PHANODERMATIDAE) IN TURKEY: FIRST RECORD OUTSIDE THE TYPE LOCALITY

“…This represents the first report of the species out of its type locality (Yellow Sea, China) from where only a single male specimen was found and described (Huang and Cheng, 2011). Reports of free-living marine nematodes are limited in Turkey and recent studies are mainly from the Black Sea coast (Ürkmez et al 2015;Ürkmez & Brennan 2013a, b;Ürkmez et al 2011). This record also stands for the first report of the genus from the coasts of Turkey.…”

Current Views on the Diversity and Distribution of Deep-Water Meiobenthos at the Turkish Shelf (Black Sea)

“…Thus, the present paper summarizes the results of the analysis of meiobenthos samples obtained at the Black Sea exit of Bosphorus (75-300m) during the cruises RV "Arar" (of Turkey) in November 2009, RV "Maria S. Merian" (of Germany) in April 2010 and also the results of the samples collected at the oxic/anoxic interface off Sinop (90-203 m) during the Black Sea Leg of the exploration vessel E/V Nautilus in August 2011. Material and methods, and maps of the sampling stations have been previously presented elsewhere (Sergeeva et al, 2017;Ürkmez et al 2015).…”

“…Part of the data on the taxonomic structure, abundance and distribution of the meiobenthos at the Black Sea shelf, the upper slope area off the Black Sea exit of Bosphorus and off Sinop shores along the transition zone from oxic to anoxic conditions has been previously published Brennan et al 2013;Ürkmez et al 2015). Nevertheless, data about meiobenthos of these areas at the interaction zones of oxygen and anoxic water masses are still scarce and require additions.…”

Why are nematodes so successful extremophiles?

“…Adaptation to low concentrations of oxygen. Nematodes can thrive in oxygen concentrations as low as 1.44 µM [ 13 ] – more than thousand times lower than atmospheric oxygen at sea level, and accordingly are the most common animal taxon in many environments with low oxygen concentration [ 14 ]. III .…”