First record of Arctodiaptomus wierzejskii (Richard, 1888) (Copepoda Calanoida Diaptomidae) from Malta

Diaptomid copepods belonging to the genus Arctodiaptomus Kiefer, 1932 were collected in two temporary water bodies in Malta. The morphological identification of the collected specimens proved that they belong to Arctodiaptomus wierzejskii (Richard, 1888) even if a morphological peculiarity pertaining to the morphology of the male right antennule of the Maltese populations was observed and here briefly discussed. This finding constitutes the first record of a calanoid copepod from the inland waters of the Maltese Islands.

A second record of Entoloma azureoviride (Agaricales, Basidiomycota) from Brazilian Amazon

ABSTRACT A new material collected and the holotype of Entoloma azureoviride were studied. The analysis of these specimens showed some discrepancies with the protologue which are discussed here. The diagnostic characters of this species are the following: fibrillose pileus, blue lamellae, cuboid spores, and abundant oleiferous hyphae in the lamellae trama. It was also observed a peculiar pseudoparenchymatous pileus trama consisting of inflated elements up to 25 µm in diam., that become more elongated towards the hymenium. A comparison of E. azureoviride with other species with blue tints in the subgenus Inocephalus and a discussion about its morphological peculiarity are provided.

Morphological adaptation of the calamistrum to the cribellate spinning process in Deinopoidae (Uloboridae, Deinopidae)

Spiders are famous for their silk with fascinating mechanical properties. However, some can further produce, process and handle nano fibres, which are used as capture threads. These ‘cribellate spiders’ bear a specialized setae comb on their metatarsus (calamistrum), which modifies cribellate nano fibres to assemble a puffy structure within the capture thread. Among different species, the calamistrum morphology can differ remarkably. Although a model of thread production has been established for Uloborus plumipes , it is not resolved if/how different shaped calamistra influence the production process. We were able to transfer the model without restrictions to spiders with different shaped calamistra. Fibres are not locked between setae but are passing across a rather smooth surface-like area on the calamistrum. This area can be relocated, explaining the first morphological difference between calamistra, without changing the influence of the calamistrum on fibres. By performing an elongated leg movement, contact between fibres and calamistrum could be adjusted after finishing thread production. This movement has to bring the thread in contact with the second morphological peculiarity: cribellate teeth. We suggest these teeth are used to handle the thread independently of the spinnerets, a feature only necessary for spiders, which do not move during web construction.

First record of the nematode Aviculariella alcedonis (Yamaguti et Mitunaga, 1943) (Spirurida, Acuariidae) in Europe, with SEM observations and comments on its taxonomic position

Aviculariella alcedonis (Spirurida, Acuariidae) is recorded from Alcedo atthis (Coraciiformes, Alcedinidae) from Bulgaria (new geographical record). A description of female specimens based on light-microscopy and SEM studies is presented. On the basis of the observations of the cephalic end, the position of the genus is considered to be in the subfamily Acuariinae, not in the Seuratiinae where it was previously placed. The host range of Aviculariella spp. is recognised as restricted to birds of the family Alcedinidae. A new morphological peculiarity described in A. alcedonis is the presence of a pair of sublateral ribs at the anterior end of each pseudolabium.

Panel Discussion: Definitions of the Tidal Interaction and Merger Phenomena

Several panelists stressed the need for care in defining observational criteria for considering a system interacting, beyond some kind of morphological peculiarity. Inevitably, some theoretical guidance is needed in this kind of interpretation. For example, narrow bridges and tails are well understood as results of certain kinds of interactions involving disk systems. Heckman stressed that such features should be seen in the old stellar population (the “Crimson Tide” approach) to avoid confusion with line emission or modest amounts of recent star formation that might have been influenced by hydrodynamical processes. Systems of these kinds will generally have an identifiable companion, perhaps tidally stripped or with its own tidal distortions, allowing further consistency checks on an interaction.