In contrast, neither entoproct
transcriptome produced clear TLR homologs, and the nemertean Malacobdella grossa produced only one questionable hit.
Decapod crustaceans, entoprocts
, polychaetes and gastropods all have high proportions of native species (over 70%, see Table 4).
Results of the study, by an international research team, suggest that entoprocts appeared earlier than previously thought.
Entoprocts are small organisms that feed by straining food particles from water.
Some anatomical characteristics of Cotyledion tylodes are comparable to those of modern entoprocts, especially the presence of a U-shaped gut with a mouth and anus surrounded by a crown of tentacles.
The most important of these are the evolution of segmentation at the base of the annelid-cchiuran-sipunculan line, multiplication and fusion of the ventral nerve cords in several annelid/echiuran taxa as well as in the sipunculans, the secondary loss of segmentation in Sipun-cula, and the evolution of tetraneury and a complex apical organ with eight to ten central flask cells and a number of peripheral cells in the Tetraneuralia (entoprocts and molluscs) (Fig.
Detailed ultrastructural investigation of the entoproct creeping larva revealed a number of shared characters with the molluscan groundpat-tern, including a distinct creeping foot with a ciliated gliding sole (see Fig.
Similar features were noted for the creeping larva of the entoproct
Loxosomella murmanica (Wanninger et al., 2007).
The purpose of this investigation was to describe thoroughly the sexual mode of one barentsiid kamptozoan (entoproct), Barentsia hildegardae, by examining all three levels of colonial organization and monitoring them over time.
The adult and larval morphology and life history of the entoproct Barentsia gracilis (M.
(Although in some pterobranchs the mesosome completely surrounds the mouth, tentacles are not present between the mouth and the region in which the cephalic shield attaches.) This arrangement is fundamentally different from that of other suspension-feeding organisms such as entoprocts (in which both the mouth and anus are surrounded by tentacles) or some polychaetes (e.g., serpulids, in which several segments of the organism are devoted to the tentacular apparatus).
In the suspension-feeding entoprocts, the direction of water flow is reversed (3).