Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin, with lectotype designations

Triphoridae is a family of marine caenogastropods with worldwide distribution. Its maximum diversity is in the Indo-Pacific province, where it is among the five most species-rich families. Taxonomic knowledge is scant and complicated by the high diversity and intra-specific variability. Knowledge of type specimens of described taxa is the fundamental first step for a taxonomic revision of the family. The Museum für Naturkunde hosts one of the most significant triphorid collections, which includes material described by W. Dunker, L. Pfeiffer, J. Thiele and E. von Martens. Type material of 29 species is described and illustrated; where appropriate, lectotypes have been designated to stabilize nomenclature. The specimens of one species, Triforis delicatula Thiele, do not fully match the original description and we refrain from selecting a lectotype, although we profusely illustrate them. Although not type material, specimens of Triforis tricincta Dunker have been included in this work to contribute to the knowledge on Dunker’s species. For all species, the original descriptions in German or Latin are reported, with a full translation into English, and remarks have been added where appropriate

Characterizing catch variability in a multispecies fishery: implications for fishery management

Exploiting several fish species simultaneously reduces variability in daily catches. The reduction depends on the number of species, the catch-frequency distributions of individual species, and the level of co-occurrence of species in the catch. We explore theoretically the reduction of variability (coefficient of variation; CV) in the total catch by combining the distributions of daily catches of individual fish species, including zero catches, into a total catch frequency distribution. Theoretical findings are tested with an example from a stationary lift-net fishery for schooling small pelagic species around Ambon Island in the Central Moluccas, Indonesia. This fishery catches over 30 species, all with high daily variability (CV=2.2–13.4). The reduction of variability in the total catch (CV=1.7) is a result of the dominance and independent occurrence of the three main species. We conclude that in this fishery the information value of the total catch as an indicator of the catches of the individual species is low

Soortenlijst Nederlandse Noordzee

In dit rapport is een soortenlijst opgesteld voor de Nederlandse Noordzee in opdracht van het ministerie van Economische Zaken. Er is behoefte aan een concrete lijst van inheemse en niet-inheemse Noordzeesoorten omdat het rijk direct en indirect werkt aan behoud en duurzaam gebruik van de van nature voorkomende biodiversiteit van het Nederlandse deel van de Noordzee, aan beleid over “Bouwen met Noordzeenatuur” en aan het volgen van niet-inheemse soorten (exoten) in de Noordzee