Comparative phylogeography of commensal species may show congruent patterns where the species involved share a common history. Temnosewellia is a genus of flatworms, members of which live in commensal relationships with host freshwater crustaceans. By constructing phylogenetic trees based on mitochondrial COI and 28S nuclear ribosomal gene sequences, this study investigated how evolutionary his...

The polarization of cells and tissues is fundamental for tissue morphogenesis during biological development and regeneration. A deeper understanding of biological polarity pattern formation can be gained from the consideration of pattern reorganization in response to an opposing instructive cue, which we here consider using the example of experimentally inducible body axis inversions in planari...

The present study addresses the effect of varying temperature and host species on the size and shape of the opisthaptoral hard-parts in isogenic strains of Gyrodactylus salaris and G. thymalli. Variation in shape was examined using geometric morphometrics. Since the opisthaptoral hard-parts of Gyrodactylus have few specific landmarks, their shape information mostly being represented by outlines...

Wnts are secreted glycoproteins involved in a broad range of essential cell functions, including proliferation, migration and cell-fate determination. Recent years have seen substantial research effort invested in elucidating the role of the Wnt signaling pathway in planarians, flatworms with incredible regenerative capacities. In this review, we summarize current knowledge on the role of canon...

Twenty rotifers (three Bdelloidea and 17 Monogononta, including new of Encentrum and Notholca) , a platyhelminth, two nematodes, two tardigrades, one cnchytraeid worm, four c1adoccrans, two copcpods and three species of mites were recovered from five small pools on Heard Island. The results indicate that the Heard Island fauna is closer to that of Signy Island and Macquarie Island than to that ...

Molecular evidence suggests that Acoelomorpha, a proposed phylum composed of acoel and Nemertodermatida flatworms, are the most basal bilaterian animals. Hox and ParaHox gene complements characterised so far in acoels consist of a small set of genes, comprising representatives of anterior, central and posterior genes, altogether Hox and ParaHox, but no PG3-Xlox representatives have been reporte...

Parasitology has a rich tradition of studies linking taxonomy, ecology, and life cycles and development. This tradition has produced an enormous amount of empirical evidence demonstrating that parasites form highly integrated reproductive-developmental-ecological systems that are highly persistent through space and time. As well, phylogenetic studies of parasites, especially of parasitic platyh...

The unparalleled biodiversity of Lake Tanganyika (Africa) has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitat...

Planarians are flatworms that constitutively maintain adult tissues through cell turnover and can regenerate entire organisms from tiny body fragments. In addition to requiring new cells (from neoblasts), these feats require mechanisms that specify tissue identity in the adult. Crucial roles for Wnt and BMP signaling in the regeneration and maintenance of the body axes have been uncovered, amon...

Very little information is available regarding marine free-living flatworms not only from Iran, but throughout the countries surrounding the Persian Gulf and the Gulf of Oman. The present study first introduces a new euryleptid species, and then reports four pseudocerotid polyclads which inhabit Iranian shallow rocky shores of the Persian Gulf and the Gulf of Oman. Maritigrella makranica sp. no...