Abstract Amphinomida, some also known as fireworms, are not only notorious for their painful sting but painfully difficult phylogenetic placement. Current understanding of the annelid tree life suggests a close affinity with Sipuncula, unsegmented and sessile peanut worms. This sister‐group relationship is hard to explain from morphological perspective. Here, we present results our histological...

engrailed is a homeobox gene that has an important role in Drosophila segmentation. Genes homologous to engrailed have been identified in several other organisms. Here we describe a monoclonal antibody that recognizes a conserved epitope in the homeodomain of engrailed proteins of a number of different arthropods, annelids, and chordates; we use this antibody to isolate the grasshopper engraile...

As a result of their plastic body plan, the relationships of the annelid worms and even the taxonomic makeup of the phylum have long been contentious. Morphological cladistic analyses have typically recovered a monophyletic Polychaeta, with the simple-bodied forms assigned to an early-diverging clade or grade. This is in stark contrast to molecular trees, in which polychaetes are paraphyletic a...

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes, Chaetopterus sp. (n = 11) and Chaetopterus cf. appendiculatus (n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabs Polyonyx cf. heok and Polyonyx sp., the pinnotherid crab Tetrias sp. and the tergipedid nudibranch P...

Deep-sea hydrothermal ecosystems are considered oases of life in oceans. Since the discovery of these ecosystems in the late 1970s, many endemic species of Bacteria, Archaea, and other organisms, such as annelids and crabs, have been described. Considerable knowledge has been acquired about the diversity of (micro)organisms in these ecosystems, but the diversity of fungi has not been studied to...

Recently specimens of the polychaete Marphysa sanguinea (Montagu, 1813) (Annelida: Eunicida: Eunicidae) were reported as an introduction to the Eastern Scheldt in southwestern Netherlands. In order to confirm the species identity, material was examined with SEM and compared with material from Devon near the type locality in Cornwall, UK. These studies confirmed that this was a new record of M. ...

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72h, the two invertebrate species significantly increased ...

The entire tube wall of Dodecaceria caulleryi and D. coralii is composed of thin calcareous lamellae with a spherulitic prismatic ultrastructure. In Diplochaetetes mexicanus the tube ultrastructure is similar, but contains also some lamellae with a homogeneous structure. The biomineralization system of cirratulids has not evolved since the appearance of calcareous tubes in the Oligocene. The tu...

Annelid coenoses in wet soils reveal specific characteristics in relation to the prevailing complex of abiotic and biotic factors effective in these soils. Especially, the presence or lack of oxygen in the topsoil is of great influence for species composition and vertical distribution of annelids in wet soils. Some annelids, for example most of the smaller enchytraeids, avoid the anaerobic cond...

Aspects of feeding, such as food capture and ingestion, as well as mobility of the polychaetes Eurythoe complanata, Marphysa formosa and Diopatra aciculata, from São Sebastião Channel (São Sebastião, state of São Paulo) were observed in laboratory conditions. Eurythoe complanata, a carnivorous species, fed exclusively on pieces of fish with the aid of strong muscular retractable lips, and detec...