Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 202 (1979), S. 461-477 
    ISSN: 1432-0878
    Keywords: Crustacean sensilla ; Chemoreception ; Multiciliated dendrites ; Specialized cuticle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In addition to setae, the first antennae of Conchoecia spinirostris also bear soft sensory tubes (♀∶4 tubes + 1 seta; ♂∶2 tubes + 3 setae). These tubes were examined electron microscopically. Each tube is divided into 4 regions: the stem, the bulbous region, the main region, and the tip. A tube contains 40–60 multiciliated dendrites, some hypodermal cells, and nonneuronal cells, and it has a specialized cuticle. Each dendrite develops within the tube, on the terminal 5–8 μm of its inner dendritic segment, approx. 25 cilia in a 9 × 2 + 0 pattern, whose rootlets are absent or only poorly developed. Each cilium splits up into 9 ramifications which extend into the tip. These ramifications partly take a spirallike course and form a ring in the distal main part beneath the cuticle. Their membranes often dilate into spindleshaped swellings. In the center of the middle and distal parts of the main region approx. 7 dendrites without cilia are located, one of them reaches into the tip. The poreless cuticle is extremely delicate and electron lucid. In contrast to the cuticle of the setae it is elastic and soft. Special substructures are described. The tubes are completely covered by a filamentous surface coat. Because of the structure and the thin walled nature of the cuticle, permeability for dissolved substances is assumed. The ciliary ramifications are likely to represent the receptive apparatus. The sensory tubes are interpreted as chemoreceptors. They can best be compared with the chemoreceptors of certain crustaceans, but differ strongly from the types of sensilla found in insects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 235 (1984), S. 117-128 
    ISSN: 1432-0878
    Keywords: Crustacean sensilla ; Molting ; Cuticle ; Aesthetasc ; Chemoreception
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In Asellus aquaticus certain distal antennular segments bear single sensilla referred to as aesthetascs. These show a proximal stem and a distal bulbous region. Depending on its position, each aesthetasc is innervated by either 50–60 or 70–80 bipolar sensory cells, the perikarya of which are situated within the pedunculus. Within the antennular segment the dendrites develop unbranched cilia (9 × 2 + 0 structure). The sensory cells are unusual in that mono- as well as biciliary dendrites are present within a single aesthetasc, the ratio of both types being correlated with the number of sensory cells. Cilia and receptor lymph cavity are enveloped by a set of 3–4 inner and 13–14 outer sheath cells, which terminate at the base of the sensillum, so that the delicate and poreless cuticle of the bulbous region encloses only outer segments within the receptor lymph fluid. A new molting type in arthropods is described in which the outer sheath cells alone build the new cuticle, whereas the inner sheath cells most probably have a protective function. A definition of aesthetascs is proposed based on finestructural criteria. Functionally the sensilla are considered to be chemoreceptors. This assumption is confirmed by experiments with diluted vital dye as well as lanthanum showing that dissolved substances penetrate the poreless cuticle instantaneously.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...