Thaliacean distribution and abundance in the northern part of the Levantine Sea (Crete and Cyprus) during the eastern Mediterranean climatic transient, and a comparison with the western Mediterranean basin

Abstract

First results are presented on the composition, abundance and vertical distribution of the thaliacean fauna in the Levantine basin obtained from stratified tows at three deep-sea sites in 1993: SE off Crete, and SW and NE off Cyprus. Samples with a 10 m 2 -MOCNESS (mesh size 1.67 mm) were poor in species and specimens as compared to samples with a 1 m 2 -double-MOCNESS (0.333 mm). Of the 12 species identified, six species belonged to the most abundant Doliolida, predominated by the phorozooids of Doliolum nationalis, five species belonged to the Salpida and one to the Pyrosomatida. Thaliaceans, most abundant by species and numbers SE off Crete, comprised B0.2% of the local mesozooplankton standing stocks. Presumably, they did not contribute substantially to the vertical flux generating the locally increased biomass and activity of the microbial benthos at the 4,300 m deep Cretean site. Most doliolids and salps were collected from the epipelagic and upper mesopelagic layers, and appeared to be most abundant close to the deep maximum of chlorophyll-a. Samples below 150 m were rarely rich in specimens, although two species performed diel migrations from the mesopelagic zone into the surface layers where some vertical segregation was evidenced. The aspect of niche separation is discussed.

Interannual variations in Adriatic Sea zooplankton mirror shifts in circulation regimes in the Ionian Sea

“…The warm-temperate thaliacean Thalia orientalis, common in the northern Levantine Basin (Weikert & Godeaux 2008), was observed for the first time in the Adriatic Sea in 2007. In 2008, the annual contribution of T. orientalis to total Salpida abundance in the southern Adriatic increased markedly (Fig.…”

New Mediterranean Marine biodiversity records (December, 2013)

“…In the eastern Mediterranean Sea, S. maxima has been reported from the coastal waters of Egypt (Abdel-Aziz & Aboul-Ezz, 2003) and the north Levantine Sea (Mutlu, 2005). The species was not collected at three sites of the Levantine Sea (south of Kriti and Cyprus) in June 1993 (Weikert & Godeaux, 2008) and its presence is hitherto unknown in other regions of the eastern Mediterranean Sea. Felimida britoi (Fig.…”

Horizontal and vertical distribution of mesozooplankton species richness and composition down to 2,300 m in the southwest Atlantic Ocean

“…Otherwise, the extension of the depth distribution is possible, in view of the lack of studies in deep habitats in the southwest Atlantic Ocean. Some species that contributed to the delimitation of all groups, occurring from the surface to the deep water masses, were previously classified as epipelagic until this study, e.g., Parasagitta friderici (CASANOVA 1999, LIANG & VEGA-PÉREZ 2001, while the other species had been recorded from the deep ocean, e.g., Oncaea venusta, Flaccisagitta enflata, and Doliolum nationalis (OZAWA et al 2007, WEIKERT & GODEAUX 2008, DIAS et al 2010. In the SS, during both study periods, Corycaeus giesbrechti and Liriope tetraphylla contributed to the delimitation of this group.…”