For the purposes of this review, the attachment strength of eggs is defined as the force required to pull an egg off a substrate. For eggs of the blue mussel (Mytilus edulis), the data presented in Brenner and Buck (2010) were used, and the data in Castro and Podolsky (2012) were considered only if pull forces exceeded 30 mN. Figure 2 in Castro and Podolsky (2012) clearly reveals the attachment strength of blue mussel eggs, which is approximately 10 mN. The detachment forces of asparagus beetle eggs and marine snail eggs were extracted from figures in Voigt and Gorb (2010) and Castro and Podolsky (2012), respectively.
The measurements were carried out in the laboratory of the Max Planck Institute of Biogeochemistry, Jena, Germany. The eggs were removed from the female by a micropipette, and the mucus was removed from the first seta using a micropipette and a micro forceps. After drying the eggs on a paper pad, the attachment strengths of the mucus of the second and third setae were measured using a digital microforce tensiometer (Instron, Materials Testing Systems, Norwood, MA, USA). The force measurements were performed in the water-free state of the eggs. The reported attachment strength of the eggs of the asparagus beetle Crioceris asparagi is significantly higher than those of the mucus of the first seta of the littoral goby. The attachment strength of its mucus of the first seta is, however, 2.
For egg attachment measurements, the eggs were placed on the lower end of a soft ($ 827ec27edc