DOI: 10.5061/dryad.qz612jmm1
title: Prezygotic reproductive barriers in precopulatory behavior of tidepool copepod species

description: Complexity in prezygotic mating behavior can contribute to the emergence
 of sexual incompatibility and reproductive isolation. In this study, we
 performed behavioral tests with two tidepool copepod species of the
 genus Tigriopus to explore the possibility of precopulatory
 behavioral isolation. We found that interspecific mating attempts failed
 prior to genital contact and that this failure occurred at different
 behavioral steps between reciprocal pairings. Our results suggest that
 prezygotic barriers may exist at multiple points of the behavioral process
 on both male and female sides, possibly due to interspecific differences
 in mate-recognition cues used at those “checkpoints”. While many copepod
 species are known to show unique precopulatory mate-guarding behavior, the
 potential contribution of prezygotic behavioral factors to their isolation
 is not widely recognized. The pattern of sequential mate-guarding
 behaviors may have allowed diversification of precopulatory communication
 and contributed to the evolutionary diversity of the Tigriopus copepods.
 The .xlsx file registered here contains original datasets for Figures 4,
 5, 6, and 7 and Table 1 in our manuscript.
description: The data were obtained by video and microscopic observations of
 interspecific and intraspecific mating behavior of tidepool copepods,
 <em>Tigriopus</em> <em>californicus</em>
 and <em>Tigriopus</em> <em>japonicus</em>. For
 detailed methods, see the published manuscript as well as Tsuboko-Ishii S,
 Burton RS. Individual Culturing of <em>Tigriopus</em> Copepods
 and Quantitative Analysis of Their Mate-guarding Behavior. <em>J Vis
 Exp. 2018 </em>Sep 26;(139):58378 (doi: 10.3791/58378). Figure 4. Difference in frequency of approaches by males between conspecific and interspecific pairs. Each datapoint was obtained from one tested pair. One approach is defined as a swift (&lt;0.5 s) chase or pounce by a male. Figure 5. Difference in mean velocity of captured females between conspecific and interspecific pairs. Each datapoint was obtained from one observed attempt.  Figure 6. Difference in paring duration between conspecific and interspecific pairs. Each datapoint was obtained from one tested pair. Figure 7. Duration of each step of prezygotic behavioral process in conspecific and interspecific pairs. Datapoints represent average duration of each behavioral step per tested pair. Pair formation: time spent from body contact to either initiation of crawl down or termination of pairing, whichever the earlier.
description: This .xlsx file was created with Microsoft Excel for Mac (version
 16.75). Figure 4. Difference in frequency
 of approaches by males between conspecific and interspecific pairs. Each
 datapoint was obtained from one tested pair. One approach is defined as a
 swift (&lt;0.5 s) chase or pounce by a male. Fig
 4A. Frequency of approaches by <em>T. californicus</em> males
 toward conspecific (<em>T. californicus</em>) and
 heterospecific <em>(T. japonicus</em>) females. The unit is
 times/min (number of approaches per free time). Fig
 4B. Frequency of approaches by <em>T. japonicus</em> males
 toward conspecific (<em>T. japonicus</em>) and heterospecific
 (<em>T. californicus</em>) females. The unit is times/min
 (number of approaches per free time). 
 Figure 5. Difference in mean velocity of captured females
 between conspecific and interspecific pairs. Each datapoint was obtained
 from one observed attempt.  Fig 5A. Mean velocity of
 <em>T. californicus</em> females against conspecific
 (<em>T. californicus</em>) and heterospecific (<em>T.
 japonicus</em>) males. The unit is mm/s. Fig
 5B. Mean velocity of <em>T. japonicus</em> females against
 conspecific (<em>T. japonicus</em>) and heterospecific
 (<em>T. californicus</em>) males. The unit is mm/s.
 Figure 6. Difference in paring duration
 between conspecific and interspecific pairs. Each datapoint was obtained
 from one tested pair. Fig 6A. Average pairing
 duration of<em> T. californicus</em> females with conspecific
 (<em>T. californicus</em>) and heterospecific (<em>T.
 japonicus</em>) males. The unit is seconds. Fig
 6B. Avarage pairing duration of<em> T. japonicus</em> females
 with conspecific (<em>T. japonicus</em>) and heterospecific
 (<em>T. californicus</em>) males. The unit is
 seconds. Figure 7. Duration
 of each step of prezygotic behavioral process in conspecific and
 interspecific pairs. Datapoints represent average duration of each
 behavioral step per tested pair. Pair formation: time spent from body
 contact to either initiation of crawl down or termination of pairing,
 whichever the earlier.<br> Fig 7A. Average
 duration of the pair formation process: time spent from body contact to
 either initiation of crawl down or termination of pairing, whichever the
 earlier. The unit is seconds. Fig 7B. Average
 duration of the crawl down by males. The unit is seconds.
 Fig 7C. Average duration of the dorsal bend by males. The unit
 is seconds. Fig 7D. Average duration of the genital
 press by males. The unit is seconds. Fig 7E. Average
 duration of the whole pairing. The unit is seconds.