This Excellent BBC Radio 4 programme The Life Scientific – A passion for Fruit Flies interviewed Professor Charalambos Kyriacou about body clocks in animals and circadian rhythms. The latter part of the programme discusses tides and body clocks, particularly that of the speckled sea louse. Fascinating stuff about tidal life.
I decided to email Professor Kyriacou with a question and he very kindly replied. And he also kindly agreed that I could post or email exchange here. So here it is.
From: Owain Jones <email@example.com>
Dear Professor Charalambos Kyriacou
I study tides – but via cultural / arts and humanities approaches.
I have a very quick follow up question after your fascinating interview with Jim Al-Khalili on BBC Radio 4 yesterday.
So, the speckled sea louse has a moon responding cycle in its habits which is 12.4 hours. And you said, it does so ‘because that is when the tide comes in and out’.
But around the world there are a whole range of different tidal patterns and rhythms which don’t correspond to 12.4 rise and fall. This is also so around the coast of the UK, where local geographies shape tidal rhythms and times. For example, there are 4 high tides a day in the Solent as the tides wash around the Isle of White.
So I am wondering, although I am sure the sea lice will have body clocks, which would make them follow the 12.4 hour lunar rhythm in the lab, maybe, in the actuality of local conditions, their habituated response to the environment would have to override that, and rather correspond to local tidal rhythms and durations.
This is copied to my friend and colleague Professor Heather Green of Arizona State University , who also studies a tidal landscape in the Gulf of Mexico https://www.heathergreen-art.com/tidal-timespace
Dear Owain, thanks for getting in touch…….sure, tides are location specific….and you are correct, I would imagine that if you take animals in some of these more esoteric tidal locations and put them in constant conditions immediately in the lab to measure their cycles they might not be 12.4 h. In fact that is exactly what we do with Eurydice – we move them immediately from the beach to the lab and their 12.4 h cycles are perfect, because the local tides are 12.4 h. The question though is whether an animal exposed to 4 tides, when placed immediately in constant conditions to express its endogenous cycle will reveal a 12.4 or 6.2 h dominant cycle? Of course on the beach it will be entrained to 6.2 h, but the genetically encoded oscillator I bet would be 12.4, because the circatidal ancestors of those animals would have evolved in a more conventional tidal environment – that’s my bet anyway…..I’ll look into the literature to see whether anyone has done the experiment……… nice one………….best, Bambos
Charalambos P. Kyriacou, FMedSci
Professor of Behavioural Genetics
Department of Genetics and Genome Biology,
University of Leicester.
I copied the emails to my friend and tidal colaborator Heather Green at Arizona State University. See something our shared work here. Tidal Timespace.