A supplement to the amphipod (Crustacea) species inventory of Helgoland (German Bight, North Sea): indication of rapid recent change

Abstract

The surroundings of the rocky island of Helgoland (German Bight, south-western North Sea) are one of the best-studied sites in European seas with species occurrence data available for nearly 150 years. As the area is strongly affected by global change (e.g. increase in mean sea surface temperature at Helgoland by 1.678C since 1962), ecosystem structure and function are expected to change more than those of average marine systems. The paper presents a supplement to the local amphipod species inventory (5 nautical miles around the island). At least seven species of this ecologically important taxon seem to have newly established themselves at Helgoland since the late 1980s: Ampelisca typica, Amphilochus brunneus, Caprella mutica, Cheirocratus assimilis, Monocorophium acherusicum, Orchestia mediterranea and Orchomenella crenata. Most of them are not only new for the Helgoland area, but also for the German Bight; and two species (Amphilochus brunneus and Orchomenella crenata) are even new to the North Sea as a whole. Out of the seven new species, one (Caprella mutica) is a neozoon from the north-western Pacific. The other six species show clear warm water affinities (oceanic -Lusitanian species) which suggest a recent range expansion in the context of climate warming. The establishment of an increasing number of species formerly probably absent from the area does not seem to be compensated by losses of species, so that local species diversity is expected to increase.

The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

“…the German Bight) and more species in the central and northern North Sea [ 51 – 54 ]. Furthermore, species with a typical Mediterranean-Lusitanian distribution are also known to occur in parts of the North Sea where oceanic influences prevail [ 55 ].…”

Amphipod family distributions around Iceland

“…Although Gitana was recorded as a deep and cold-water associated genus in the IceAGE samples, it is known to occur commonly at shallow depths in the North Sea (Beermann and Franke 2011) and the Mediterranean Sea (Krapp-Schickel 1982). However, an affinity with deep and cold water is recognised for the very widely distributed new species Amphilochus anoculus (Tandberg and Vader 2018) and Amphilochopsis hamatus .…”

New records of Ericthonius didymus Krapp-Schickel, 2013 (Crustacea: Amphipoda: Ischyroceridae) in European waters with a focus in Arcachon Bay, France and key to Ericthonius species

“…The genus Ericthonius has a complicated taxonomic history, principally due to the lack of clear interspecific differences in females, and to intraspecific variability of male gnathopod 2 according to growth stage. As a result, Ericthonius species have undergone a series of erroneous synonymizations and consequent mis-identifications (Myers & McGrath, 1984; Chapman, 2007; Beermann & Franke, 2011; Krapp-Schickel, 2013; Marchini & Cardeccia, 2017). Some species within this genus, namely E. brasiliensis (Dana, 1853), E. difformis H. Milne Edwards, 1830, E. pugnax (Dana, 1852), E. punctatus (Spence Bate, 1857) and E. rubricornis (Stimpson, 1853), have been reported to have a very wide geographic distribution.…”