A molecular phylogenetic study of Cucujidae s.l. (Coleoptera: Cucujoidea)

Of all the superfamilies within the megadiverse order Coleoptera (Insecta), Cucujoidea (Cucujiformia) is arguably the most problematic taxonomically. The families comprising Cucujidae s.l. (Silvanidae, Laemophloeidae, Passandridae and Cucujidae s.s. represent a large portion of cucujoid diversity. Herein we present the results of a rigorous molecular phylogenetic analysis of Cucujidae s.l. using maximum‐likelihood and Bayesian analyses of seven genes. Representatives of over half of the families of Cucujoidea (excluding the cerylonid series), as well as a broad sampling of Silvanidae and Laemophloeidae, were analysed. The monophyly of Cucujidae s.l. is rejected but a subgrouping of taxa that may form the core of a natural cucujoid lineage is recovered. This clade consists of two large monophyletic groups including several families each. Relationships among these smaller cucujoid groups are discussed, including several novel phylogenetic hypotheses, whereas morphological characters considered significant for classification in Cucujidae s.l. are evaluated in light of these phylogenetic hypotheses. Silvaninae, Telephanini, Brontini and Brontinae are recovered as monophyletic in the Bayesian analysis, but the former two are recovered as paraphyletic in the maximum‐likelihood analysis. Our results support the placement of Psammoecus Latreille within Telephanini and also recover a paraphyletic Telephanus Erichson. Silvaninae is divided into three lineages, each representing a potential tribal lineage. Laemophloeidae is rendered paraphyletic in all analyses by Propalticidae and the latter is herein formally transferred to Laemophloeidae stat.n . Several suprageneric laemophloeid clades are recovered and discussed as potential higher‐level groups. Laemophloeus Dejean is not recovered as monophyletic.     

Paleolimnology and trends in the phosphorus and iron budgets of an old man-made lake, Barton Broad, Norfolk

SUMMARY. Barton Broad, Norfolk is a shallow, eutrophic lake. During the last 30 years submerged macrophytes have declined and phytoplankton numbers have increased. This change is traced through the stratigraphy of a 60-cm mud core. Diatom frustule counts of 1-cm sections of the core showed that an epiphyte-dominated diatom community was replaced by a planktonic community. From chemical analysis and radio-isotope dating of the core, sedimentation rates and past phosphorus and iron loadings are estimated. Sedimentation rates were between 1.2 mm and 3.1 mm year⁻¹ during the early part of the core but doubled in the 1950s to 5 mm year⁻¹, doubled again in the 1960s and have increased to 12 mm year⁻¹ in the 1970s. Retention of phosphorus in the sediment increased from 0.5 g m⁻² year⁻¹ to 18–21 g m⁻² year⁻¹ in two steps. A similar trend is shown for iron. The diatom species composition and chemistry of the core sections are correlated with increased nutrient loading and the decline of macrophytes. Contemporary phosphorus and iron budgets are calculated from inflow–outflow data and balanced using sediment retentions estimated from the core data. It is believed a large proportion of phosphorus and iron enters the Broad by movement of sediment along the river bed. A reduction of 25% of the 1975 phosphorus loadings would probably permit re-establishment of some macrophytes. The present chemistry and algal communities of Barton Broad and the River Ant are described.     

The systematics of British larval lampreys

Several taxonomic characters, including the number of trunk myomeres, proportional body measurements and patterns of external and internal pigmentation, have been investigated in populations of ammocoetes belonging to the three species of lampreys found in British rivers. Petromyzon marinus can be readily distinguished by the pigmentary pattern in the tail and on the oral hood, and by the much higher number of trunk myomeres. Although no character can be used to separate with certainty the larvae of Lampetra fluviatilis and Lampetra planeri , significant differences were found between the mean number of trunk myomeres in the two species. Moreover, the values for ammocoetes were virtually identical to those of the respective post-larval stages, at which phase in the life cycle the two Lampetra species are clearly distinguishable. The incidence of pigmentation on the tongue precursor was much higher in larval populations of L. fluviatilis than in those of L. planeri and there was also a difference in the rate of change in the relative length of the trunk and tail. Where comparisons can be made, the results in this paper are in agreement with those of most other European and North American workers. The data differ markedly, however, from that contained in the only other previous detailed systematic study on British larval lampreys, which was subsequently used as the basis for taxonomic keys.