Institute for Applied Ecosystem Research

ABSTRACT Since 2004, a logbook study has been conducted with commercial fishers to generate yellow eel specific catch per unit effort (CPUE) data in the German part of the southern Baltic Sea. By the end of 2023, this data series covers a 20‐year period. Using a change point analysis, various shifts in the fyke net CPUE data series for under‐sized and legal‐sized yellow eels were detected, with increased mean monthly CPUEs within the last years. In contrast to the most recent recruitment trend, the CPUE data series indicate a slight increase of the yellow eel abundance in the study region. Possible causes contributing to this trend are discussed. Implications for the current debate on European eel conservation efforts are also highlighted.

Eleven species of Malmgrenia McIntosh, 1874 are currently recorded from the Northeast Atlantic and Mediterranean Sea. In eight of them, all long notochaetae have stout, entire tips [Malmgrenia andreapolis McIntosh, 1874; M. arenicolae (Saint-Joseph, 1888); M. castanea McIntosh, 1876; M. lilianae (Pettibone, 1993); M. ljungmani (Malmgren, 1867); M. lunulata (Delle Chiaje, 1830), M. mcintoshi Tebble & Chambers, 1982 and M. polypapillata (Barnich & Fiege, 2001)]. They differ by their elytral, parapodial and neurochaetal characters. Three additional species [Malmgrenia darbouxi (Pettibone, 1993), M. marphysae (McIntosh, 1876) and M. louiseae Jourde, Sampaio, Barnich, Bonifacio, Labrune, Quintino & Sauriau, 2015] can be separated from this group by their long notochaetae tapering to a fine, entire tip. Meanwhile, we found two new species in the area, Malmgrenia bicki sp. nov. and Malmgrenia thomsonae sp. nov., both with some long notochaetae showing a fine, bidentate tip (i.e. with subdistal tooth), but differing mainly by the shape of their supra-acicular process and middle neurochaetae. The presence of bidentate notochaetae first led to confusion with Pettibonesia furcosetosa (Loshamn, 1981), originally described as Malmgrenia as well. But in this species, some of the long notochaetae terminate in a fine furcate (i.e. distally split) tip. The discovery of the two new Malmgrenia species led us to re-assess the generic characters of the genera Malmgrenia and Pettibonesia Nemesio, 2006. As a result, we consider the presence of small cephalic peaks as a character of generic importance for Pettibonesia, especially since cephalic peaks are not found in any of the Malmgrenia species described for the area. The bidentate condition of some notochaetae suggests that the two new species could be assigned to Pettibonesia, but the fact that both new species lack cephalic peaks led us to assign them to Malmgrenia.

Mit Hilfe der Ethohydraulik wurden von den Autoren verschiedene Untersuchungen durchgefuhrt, deren Ergebnisse bis dato nicht oder nur auszugsweise veroffentlich sind. Vor diesem Hintergrund werden die Erkenntnisse aus bisherigen Projekten zu Aspekten der Funktionsoptimierung von Fischaufstiegsanlagen, der Wirksamkeit von Fischschutzeinrichtungen, der Auffindbarkeit von Bypassen, der Reaktionsweise von Fischen gegenuber Wasserradern sowie auch der Moglichkeit numerische Stromungssimulationen fur eine fischvertraglichere Planung wasserbaulicher Anlagen einzusetzen dargestellt. Hieraus werden Regeln und Bemessungswerte fur die Planung und das Design solcher wasserbaulichen Anlagen abgeleitet und kritisch beurteilt.

Im Zusammenhang mit Verhaltensbeobachtungen von Fischen im wasserbaulichen Labor sind zahlreiche tierschutzrechtliche und technische Aspekte zu berucksichtigen. Es werden konkrete Empfehlungen zum Umgang mit Fischen, vor, wahrend und nach ethohydraulischen Tests gegeben und ausfuhrlich die fur den Aufbau und den Betrieb eines ethohydraulischen Versuchsstandes benotige Infrastruktur sowie Mess- und Dokumentationsgerate beschrieben.

The paper presents a comprehensive revision of the genus Spiophanes (Polychaeta, Spionidae) based on type material. The identity of Spiophanes kroyeri, the type species of the genus, is fixed by lectotype designation. Enhanced diagnoses with illustrations, notes on their distribution and comments on species identification for all valid species are provided. S. chilensis Hartmann-Schröder, 1965 and S. söderströmi Hartman, 1953 are synonymized with S. duplex (Chamberlin, 1919). S. kroyeri reyssi Laubier, 1964 is raised to species status. S. fimbriata and S. malayensis are considered as valid species not synonymous with S. kroyeri. Also, 8 species are newly described: S. algidus, S. mediterraneus, S. inflatus, S. afer, S. kimballi, S. similis, S. longisetus and S. aucklandicus. An identification key to species of Spiophanes is given.(© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)