As photographedb y van Montfranse t

As photographedb y van Montfranse t al. (1986), the
tag was implantedt hrought he articulatingm embrane
of the base of the fifth pereiopod into the relatively
largeb asalm uscleo fthat appendage( the "backfinm uscle").
Orientation was such that the tag's length was
parallel to the muscle fiber bundle. The depth of implantation
into the muscle varied with the size of the
crab in such a way that the tag was always placed in
the middle of the muscle cavity; this was controlled
with a movable plastic mold against which the crab
was held during injection. The mold was shaped so
that a crab of any size could be fitted into position on
the mold in a consistent orientation. The hypodermic
passed through the mold into the crab, with the in-out
position of the mold controlling the depth of insertion
of the hypodermic and the tag. Practice was required