Table 1 Common reproductive behaviours of squat lobsters in laboratory conditions at 7 ± 0.5°C (modified from Jivoff and Hines 1998)

Approach

The male moves towards, and tries to grasp the female. The attempt fails and individuals do not remain together for more than 4 s

Precopulatory embrace

The male grasps the female and holds her for more than 4 s, up to hours. They may be positioned one in front of the other: rostrum-to-rostrum position (Fig. 2a), or the male on top of the female so that his sternum rests on her dorsal carapace both facing the same direction: sternum-to-carapace position (Fig. 2b). Durations: CL ♂ ≈ ♀: 57 s ± 3 min 48 s, range: 4 s to 58 min 13 s (n = 522 interactions in N = 88 trios). CL ♂ > ♀: 12 min 7 s ± 34 min 38 s, range: 5 s to 3 h 47 min 51 s (n = 129 interactions in N = 38 trios)

Copulatory embrace

Once the male has the female in a precopulatory position, he places her so that their sternal surfaces are opposed, both individuals face in the same direction: sternum-to-sternum position (Fig. 2c). Durations: CL ♂ ≈ ♀: 25 s ± 22 s, range: 4 s to 1 min 10 s (n = 7 interactions in N = 6 trios). CL ♂ > ♀: 19 min 12 s ± 22 min 13 s, range: 5 s to 1 h 16 min 56 s (n = 14 interactions in N = 6 trios)

Resistance

The female resists/escapes the male’s guarding attempt, usually by tail flipping

Submission

The female does not resist the male’s guarding attempt, and remains with pereopods extended forwards against body, and with chelipeds folded in and downwards (Fig. 2b)

Corral

The male remains close to the female, and displays his chelipeds in a V shape which physically encloses the female