DOI: 10.5061/dryad.wm37pvmvj
title: Data from: Sporadic feeding regulates robust food entrainable circadian clocks in blind cavefish

description: The circadian clock represents a key timing system that enables organisms
 to anticipate the day-night cycle. To ensure synchronization with the
 environment it is entrained by various periodic signals of which light is
 the best studied. Many investigations have pointed to the existence of two
 distinct circadian oscillators: one regulated by the light-dark cycle
 (light-entrainable oscillator) and the other set specifically by feeding
 time (food-entrainable oscillator) independently of light, and which
 regulates various aspects of feeding behaviour. Blind cavefish have
 evolved under extreme conditions where they completely lack light exposure
 and also experience food deprivation. Furthermore, they are under
 particular pressure to optimize the timing of their feeding behaviour.
 Here, we have investigated feeding regulated clocks in two well-studied
 cavefish species, the Somalian cavefish Phreatichthys andruzzii and the
 Mexican cavefish Astyanax mexicanus, in comparison with the
 surface-dwelling zebrafish Danio rerio. Our results reveal that feeding
 represents an extremely strong synchronizer for circadian locomotor
 rhythmicity in subterranean cavefish. Indeed, we showed that consuming
 just one meal every 4 days is sufficient to entrain circadian rhythmicity
 in both cavefish species, but not in zebrafish. These profound adaptations
 to an extreme environment provide unique insight into the connections
 between feeding and circadian clocks.
description: Locomotor activity was measured throughout the experimental
 period by means of infrared photocells (Omron, mod E3S-AD62, Japan) placed
 against the aquarium wall. The photocells were connected to a computer,
 and every time a fish interrupted the infrared light beam it induced an
 output signal that was recorded and stored in 10-min bins using
 specialized software (DIO98USB; University of Murcia, Spain).
description: # Sporadic feeding regulates robust food entrainable circadian clocks in
 blind cavefish
 [https://doi.org/10.5061/dryad.wm37pvmvj](https://doi.org/10.5061/dryad.wm37pvmvj) We have investigated feeding regulated clocks in two well-studied cavefish species, the Somalian cavefish *Phreatichthys andruzzii* and the Mexican cavefish *Astyanax mexicanus*, in comparison with the surface-dwelling zebrafish *Danio rerio*. Our results reveal that feeding represents an extremely strong synchronizer for circadian locomotor rhythmicity in subterranean cavefish. Indeed, we showed that consuming just one meal every 4 days is sufficient to entrain circadian rhythmicity in both cavefish species, but not in zebrafish. These profound adaptations to an extreme environment provide unique insight into the connections between feeding and circadian clocks. #### Description of the data and file structure Overview of files and their contents: We organized the data for each figure presented. For each figure, there are text files (49 in total) used to generate the graphs using El Temps software v.313 ([http://www.el-temps.com/principal.html](http://www.el-temps.com/principal.html)). Text files are titled in this way: FigX_type of graph_species_feeding regime (e.g., Fig1_actogram_PA_24). Type of graph: actogram, periodogram, circular diagrams showing acrophases (to simplify, indicated as acrophase). Species: PA is for *Phreatichthys andruzzii*; DR is for *Danio rerio*; AM is for *Astyanax mexicanus*.  Feeding regime: 24 (fish were fed every 24 hours); 48 (fish were fed every 48 hours); 72 (fish were fed every 72 hours); 96 (fish were fed every 96 hours); 24shift (fish subjected to a periodic mealtime of T=24 h, which later was shifted by 8 h); 36 (fish were fed every 36 hours); 44 (fish were fed every 44 hours). Instructions for users to run the software The locomotor activity recorded were used as input file to visualize actograms, periodograms and acrophase calculations using El Temps software v.313 ([http://www.el-temps.com/principal.html](http://www.el-temps.com/principal.html)). Actograms display an organism's activity patterns over time, periodograms analyze the frequency of these rhythms to identify cycles, and acrophase refers to the time point within a cycle when activity reaches its peak. The Filter parameters set to design the actograms are:                         Type: Stop band                         window: Kaiser                         attenuation: Pass 0.100; stop 40                         decay:100 dB/oct                         cut: left 360; right 1800