COMPARATIVE MORPHOLOGY OF THE FOREGUT OF 4 GNATHOPHAUSIA SPECIES (CRUSTACEA, MYSIDACEA, LOPHOGASTRIDA) - RELATIONSHIPS WITH OTHER TAXA

The features of the foregut of Gnathophausia ingens Dohrn, 1870, G. zo ea W.-Suhm, 1875, G. longispina G. O. Sars, 1883 and G. gracilis W.-Su hm, 1875 (Crustacea, Mysidacea, Lophogastrida, Lophogastridae) are des cribed, based on scanning electron microscopy. Comparisons are made wi th the foregut of related taxa, particularly with Eucopia, the only ge nus constituting the second family (Eucopiidae) of the Lophogastrida. The foreguts of Gnathophausia and Eucopia exhibit (1) common features, which might be characteristic of the sub-order Lophogastrida, (2) mor e similarities with those of the Decapoda than those of the sub-order Mysida. But preliminary observations suggest that the stomach is obvio usly smaller than that of the similarly sized Decapoda. The foregut of Gnathophausia is morphologically unique to this genus, although each species exhibits small specific differences.