| comparative myoanatomy of cycliophoran life cycle stages. | the metazoan phylum cycliophora includes small cryptic epibionts that live attached to the mouthparts of clawed lobsters. the life cycle is complex, with alternating sexual and asexual generations, and involves several sessile and free-living stages. so far, the morphological and genetic characterization of cycliophorans has been unable to clarify the phylogenetic position of the phylum. in this study, we add new details on the muscular anatomy of the feeding stage, the attached prometheus larva ... | 2010 | 20024946 |
| three-dimensional reconstruction of the musculature of various life cycle stages of the cycliophoran symbion americanus. | cycliophora is a very recently described phylum of acoelomate metazoans with a complex life cycle and a phylogenetic position that has been under debate ever since its discovery in 1995. symbion americanus, which lives attached to the mouthparts of the american lobster, homarus americanus, represents the second species described for the phylum. aiming to increase the morphological knowledge about this cryptic clade, the present study describes the muscle arrangement of the feeding stage, the att ... | 2009 | 18937332 |
| immunocytochemistry of the nervous system and the musculature of the chordoid larva of symbion pandora (cycliophora). | to date, the phylum cycliophora comprises only one described extant species of acoelomate marine invertebrates, symbion pandora. adult specimens live commensally on the mouthparts of the norwegian lobster, nephrops norvegicus. its complicated life cycle includes an asexually produced pandora larva and a sexually produced chordoid larva. despite detailed tem investigations and its inclusion in recent molecular phylogenetic analyses, cycliophoran relationships still remain enigmatic. in order to i ... | 2005 | 15986410 |
| dwarf male of symbion pandora (cycliophora). | this study clarifies the identity and development of the male in the life cycle of symbion pandora. the male is not produced directly by the feeding stage, as previously thought, but arises as a distinct individual from budding cells inside an intermediate stage named the prometheus larva. the morphology and the development of the two distinct stages are described with light and electron microscopy. furthermore, the following terminology is suggested to clearly distinguish between the different ... | 2003 | 12520546 |
| performance of 18s rdna helix e23 for phylogenetic relationships within and between the rotifera-acanthocephala clades. | the species diversity of the phylum rotifera has been largely studied on the basis of morphological characters. however, cladistic relationships within this group are poorly resolved due to extensive homoplasy in morphological traits, substantial phenotypic plasticity and a poor fossil record. we undertook this study to determine if a phylogeny based on partial 18s rdna, which included the helix e23 of 18s rdna sequence, was concordant with established taxonomic relationships within the order pl ... | 2000 | 11098408 |