Functional morphology of the foregut of Lophogaster typicus and L. spinosus (Crustacea, Mysidacea, Lophogastrida)
De Jong, L. (1996). Functional morphology of the foregut of Lophogaster typicus and L. spinosus (Crustacea, Mysidacea, Lophogastrida). Cah. Biol. Mar. 37(4): 341-347
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more
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| Abstract |
The foreguts of two Lophogaster species (Crustacea, Mysidacea, Lophogastrida), one benthic and another pelagic, are described. Their morphology is characteristic of the genus and does not seem related with the ecology of the species, as would be expected. The foregut is very different from that observed in other Lophogastrida (Eucopia and Gnathophausia). Indeed, the cardiac chamber is followed by a large alimentary pouch occupying half the length of the cephalothorax, which probably corresponds to the dorsal pyloric chamber. Such storage system is original among crustaceans exhibiting the caridoid facies (Mysidacea, Euphausiacea and Decapoda). As the dorsal pyloric chamber is posteriorly closed by this pouch, the junction between the stomach and the intestine takes place at the level of the ventral pyloric chamber, instead of the dorsal one as in other Mysidacea. The gastric mill also is original, since the lateral teeth look like mandibles owing to their morphology and internal musculature. Lastly, at the junction with the stomach, the very small size of the lumen of the intestine probably do not allow the passage of coarse particles, contrary to what occurs in other Mysidacea, Euphausiacea and Decapoda. |
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