Urine release

Breithaupt, T., Lindstrom D. P., and Atema, J., Urine release in freely moving catheterized lobsters (Homarus americanus) with reference to feeding and social activities, J. Exp. Biol., 202, 837, 1999. 

Do male and female urine release different responses Tabulate and graph data. Use Data Sheet 20%. 

It is unknown whether crustacean senders can manipulate the composition of urineborne pheromones. They do, however, have control over the timing of urine release (Breithaupt, Chap. 13) and are therefore able to adjust the signaling to their own benefit. This may include opportunities to manipulate the receiver by either falsely reporting or by withholding information (Christy and Rittschof, Chap. 16). Only in few examples has the chemical nature of distance pheromones been characterized. These studies employed behavioral assays that used a specific behavioral response in the receiver as an indicator for pheromonal activity (Kamio and Derby, Chap. 20 Hardege and Terschak, Chap. 19). 

Another contradicting point of view was advanced by Snyder et al. (1993), based on studies of H. americanus. These authors reported that blocking urine release had no effect on intra- or intersexual behavior. Once again, although it is possible that there are additional, redundant sources of pheromones such as have been shown in crabs (Bushmann 1999), an alternative explanation is a methodological one - the methods of blocking urine release were different in these studies and the method of Snyder et al. (1993) may not have been completely successful. 

Fig. 12.5 Social interactions and urine release in Caribbean spiny lobster. Dominant animals are more likely to release urine than subordinates (a), and dominants release more urine than subordinates (b). Adapted from Shabani et al. (2009) with permission from The Journal of Experimental Biology...

Fig. 13.5 Changes in the receiver response to offensive behavior without urine release (open bars) and to offensive behavior accompanied by urine release (solid bars). Responses are measured as changes in the relative frequency of occurrence of defensive (levels —2, — 1), neutral (level 0) and aggressive (levels 1-5) behaviors. Asterisks denote significant differences between the two conditions (double asterisk p < 0.01 modified after Breithaupt and Eger 2002)...

Fig. 13.6 Mean ( SEM) urine release by dominant (gray bars) and subordinate (white bars) crayfish in male fights (MM Fight), female fights (FF Fight), mixed-sex fights (MF Fight) and reproductive interactions (Repr). In reproductive interactions males are labeled as dominant (gray bars) and females as subordinate (white bars). Asterisks indicate differences between interactants (asteriskp < 0.05, double asteriskp < 0.01, paired t-test). From Berry and Breithaupt (2010)...

Fig. 13.7 Artist impressions of the social interactions between crayfish in a population of high density. Aggressive interactions between males (on the right) involve physical contact of the claws (claw lock) and urine release. Reproductive interaction (bottom) involve male mating attempt (starting with the male seizing female antennae with left claw) and female aggressive behavior (female claw lock) with urine release. Drawing courtesy of Jorge Andres Varela Ramos...

Zulandt Schneider RA, Huber R, Moore PA (2001) Individual and status recognition in the crayfish Orconectes rusticus the effects of urine release on fight dynamics. Behaviour 138 137-153... 

Our objectives here were to 1) assess whether urine is released in a pulsatile and predictable manner by sexually inactive goldfish, and 2) determine whether pulsatile urinary release can be measured reliably in sexually-active females. To address these objectives, we injected female goldfish with either a dye or a radio-label, both known to be released in urine, and compared the results. The use of this dye to measure urine release in an aquatic organism has not been described before. 

Results. Goldfish injected with the dye released urine in visible pulses within 15 min of injection, and casual observation revealed that urine release was still noticeable approximately 2 h after the experiment ended (i.e. 3 h after injection). The rate of urinary release per 5 min interval did not change over the 60 min experimental period (Figure 1), and thus permitted us to conduct dye injection experiments over this time period with confidence. 

We compared urine release of eight male (20—26 g) and eight female (20-33 g) goldfish using a protocol modified from Experiments 1 and 2a. We eliminated the acclimation periods and conducted experiments in 8 L glass aquaria with three sides covered in translucent, white plastic. Fish were held in 75 L aquaria with 4—5 individuals of the same sex... 

Because the temporal manner with which pheromones are released might play a role in signal function, we sought to determine whether the temporal pattern of urinary release differed between species. Using dye injection, we determined the temporal nature of urine release in female Eurasian ruffe (Gymnocephalus cernuus), which have recently been demonstrated to release a behavioral sex pheromone in its urine (C. A. Murphy, University of Minnesota, unpublished data). 

Injection with isosulfan blue is a relatively non-invasive and reliable method for recording urine release and yields data with high temporal resolution. The dye does not appear to affect urinary release both because urination rate does not change during the course of the experimental period used in this study (15—75 min after injection) and because fish release urine at similar rates when injected with either dye or radiation. Thus, the urination rates reported here are likely realistic. 

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