Waterborne cues

Freshwater turtles appear to use waterborne cues to find members of the oposite sex. During the mating season, males of the Iberian peninsula terrapin. 

Although relatively few mobile invertebrates produce their own defensive compounds, many more use the defensive compounds produced by other organisms, either by physiologically sequestering them from their prey, or by developing commensal or mutualistic associations with other chemically unpalatable organisms (see Section IV.B). Additionally, some animals use waterborne cues to detect the presence of predators and adjust their behavior and use of refuges to minimize the risk of detection. 

Leonard, G.H., Bertness, M.D., and Yund, P.O., Crab predation, waterborne cues, and inducible defenses in the blue mussel Mytilus edulis, Ecology, 80, 1, 1999. 

Chemically mediated interactions have important direct and indirect effects on communities from both ecological and evolutionary standpoints.22 341 Chemical defense or communication cannot be properly understood unless it is viewed through the lenses of population, community, and ecosystem processes, and this requires consideration of both the biotic and abiotic components of the natural environment.342 For example, chemically mediated foraging is affected by water flow because it relies on water-soluble cues that are carried away from prey.343 345 Similar constraints likewise modify the effectiveness of other waterborne cues, such as alarm signals, sexual pheromones, and settlement cues, in both mobile and sessile organisms.244 345 350... 

Several other researchers have studied chemical cues influencing gregarious settlement and metamorphosis of polychaete larvae. An unidentified waterborne cue was responsible for gregarious settlement of Hydroides dianthus,89 The inducer was not associated with the tubes, but rather with the bodies of adult worms. Extractions of adult worms with organic solvents removed the inductive capacity of the tissue. The activity was found in both polar (methanol) and nonpolar (dichlo-romethane) fractions of an extraction series.89... 

There is a variety of substances produced by peracarids themselves, which mediate social interactions. Unfortunately, very little is known about the chemical nature of these substances, which are transmitted via the medium (water or air) or via direct contact. For the amphipod Microdeutopus gryllotalpa, Borowsky et al. (1987) showed that waterborne cues contain polar molecules. Some of the chemicals that... 

De Lange HJ, Liirling M, van den Borne B, Peeters ETHM (2005) Attraction of the amphipod Gammarus pulex to waterborne cues of food. Hydrobiologia 544 19-25... 

Fig. 22.1 Gregarious settlement of barnacle cypris larvae, (a) Cyprids approach the substratum, perhaps after encountering a waterborne cue released by adults (b) contact with substratum and onset of (c) searching behavior (d) cyprid contacts an adult conspecific and is stimulated to settle by a cuticular protein - the settlement-inducing protein complex (SIPC). The cyprid may return to the plankton at any stage of the sequence (b-d). Drawing by Jorge A. Varela Ramos...

Studies on the nature of waterborne cues to barnacle settlement, their relation (if any) to the SIPC and their role in the settlement process are also needed, as are studies on the transduction of cues. The latter will undoubtedly benefit from proteomic (Thiyagarajan and Qian 2008) and genomic (Bacchetti De Gregoris et al. 2009) approaches. What role biofilm associated with barnacle shell has in settlement induction also needs clarification. In the context of waterborne cues, there is evidence for other taxa that biofilm can adsorb chemical cues (e.g., Chan and Walker 1998). 

Elboume PD (2008) Ecological role of an adult-derived, waterborne cue in cyprid settlement in the barnacle Balanus amphitrite Darwin. PhD thesis, Newcastle University, pp 327... 

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