The ornamental design for the attachment structure for a fishpenfeeddisperser, as shown and described.
FIG. 1 is a perspective view of an attachment structure for a fish pen feed disperser in accordance with the present design;
FIG. 2 is a top plan view of the attachment structure for a fish pen feed disperser shown in FIG. 1, which due to symmetry is the same as the bottom plan view;
FIG. 3 is a front view of the attachment structure for a fish pen feed disperser shown in FIG. 1;
FIG. 4 is a back view of the attachment structure for a fish pen feed disperser shown in FIG. 1;
FIG. 5 is a left side view of the attachment structure for a fish pen feed disperser shown in FIG. 1; and,
FIG. 6 is a right side view of the attachment structure for a fish pen feed disperser shown in FIG. 1.
The broken line showing of a feed disperser is for the purpose of illustrating environmental structure and forms no part of the claimed design.