Jh. Swanepoel et A. Avenantoldewage, FUNCTIONAL-MORPHOLOGY OF THE FOREGUT OF CHONOPELTIS-AUSTRALIS BOXSHALL (BRANCHIURA), Journal of crustacean biology, 13(4), 1993, pp. 656-666
The morphology of the foregut of the ectoparastic branchiuran Chonopel
tis australis is described from serial transverse, longitudinal, and f
rontal sections of whole parasites and from SEM micrographs. The foreg
ut is differentiated into four histomorphological regions: a preoral c
avity, housed inside the proboscis and containing the tongue and mandi
bles; an ascending esophagus supplied with constrictor, longitudinal,
and dilator muscles; a horizontal esophagus supplied with constrictor
muscles only; and an esophageal funnel, containing cuticle-lined inner
and recurrent walls, reminiscent of the cardia of muscoid flies. The
mandibles apparently do not function as lacerating organs, but instead
cram mucus and cellular detritus into the preoral cavity. Five dentig
erous plates, guarding the oral aperture, function as a filter during
feeding. The muscle complex in the walls of the ascending esophagus fa
cilitates movement of aliment through the foregut into the anterior mi
dgut. The comparative morphology and functional significance of each p
art of the foregut are discussed.