Genetic lineage and environmental conditions as drivers of chromatosome
variation in the anchialine shrimp Halocaridina rubra Holthuis, 1963 (Caridea: Atyidae).
The ovarian chromatosome preparation employed here has been described in detail previously (McNamara and Ribeiro, 1999).
The chromatosome preparations were perfused with the various reagents for 110 to 130 min prior to adding RPCH.
Each experiment was repeated 7-9 times, using a single chromatosome in each preparation.
Located within the epidermis and in the fibrous capsules surrounding the internal organs, chromatosomes consist of 2 to 12 uninuclear chromatophores, which are irregular cells constituted by a perikaryon and one or two peripherally ramified cell extensions through which the pigment granules translocate (McNamara, 1981).
In ovarian chromatosome preparations, in vitro, RPCH washout releases the pigment matrix from complete aggregation by an unknown mechanism, which may involve a signaled decrease in myosin activity, possibly via reduced intracellular calcium (McNamara and Ribeiro, 2000), and apparently allows the microtubule system to repolymerize.
olfersi ovarian chromatosomes perfused with RPCH, maximum velocity is attained at some point between 0 and 2 min after pigment aggregation begins (Fig.
To illustrate, chromatosome pigments spontaneously disperse in shrimp epidermal preparations in vitro (Fingerman et al.
The ovarian chromatosome preparation employed has been described in detail previously (McNamara and Ribeiro, 1999).
in three phenotypes of Neocaridina denticulata Kemp, 1918: morphological and chromatic differences measured non-invasively.
Polychromatic chromatophores, on the other hand, which contain multiple types of chromatosomes in the cytoplasm, are rare in vertebrates and invertebrates.
Aggregation of both chromatosomes at the perikarion of the novel dichromatic chromatophores displayed a very dark color due to the additive color mixture of the two hues (Fig.