Dades ultrastucturals de les glàndules de la closca de "Chirocephalus diaphanus" "(Crustacea: Phyllopoda)"

Abstract

Some morphological aspects of the shell glands of Chirocephalus diaphanus are described. These glands, which are of the acinous type and attached to the external wall of the uterus, are constituted by a great number of elementary glandular units formed by the juxtaposition of two big secretory cells. These, of about 55 µm in diameter, present an ovoid nucleus whose diameter is approximately 20 &mircro;m and contain several nucleoli and abundant evenly distributed chromatin. The position of the nucleus varies along the secreting cycle, being basal or central according to the load of secreting granuli contained in the cell. In the cytoplasm, particles of β-glycogen and a large amount of ribosomes are noticed, as well as a very well developed ergastoplasm and a considerable amount of secretion granules located in the apical area and originated mainly from the Golgian vesicles.
The intercellular space, situated amongst the apical walls of the cells that form each glandular unit, suffer important modifications during the secreting cycle. So when the cells are loaded with secretion granules, such intercellular space is very reduced and only from time to time some intercellular thickenings provided with microvilli, are noticed where the contents of the secretion granules are poured. These thickenings are preceded by junctional complexes formed by a zonula adhaerens followed by a septal junction.
Generally speaking we can say that the morphology of the shell gland of Chirocephalus diaphanus is similar to that presented by the shell gland of the rest of the Anostracan species studied.