Video Dataset: Effect of salinity on early life stages of the Christmas Island red crab Gecarcoidea natalis

Dataset

Description

Data (videos of developing embryos) were collected to assess the effect of salinity on early life stages of the Christmas Island red crab Gecarcoidea natalis Methods Animal collection and experimental setup Berried Christmas Island red crabs, Gecarcoidea natalis (Pocock, 1888) (n = 2) were collected by hand from Greta Beach, Christmas Island, Indian Ocean (-10.502°, 105.675°) at 05:00 on 10th Dec 2023 and transferred to the laboratory at the Parks Australia Pink House Research Station, a 30 min drive away. Upon arrival crabs were sprinkled with sea water and transferred to individual terrariums where they were kept quiescent and maintained under ambient conditions (T = 25 °C) for 8 h. Throughout this time crabs were in good condition and displayed normal activity levels. Single eggs were then carefully removed at random with fine watchmaker forceps from the egg mass of each female and transferred to individual wells (N = 5 eggs per clutch, per salinity treatment) of a 384 well microtiter plate (70 µL/well, VWR, Radnor, PA, USA). Each well was filled with 40 µL of either 100, 75, 50, or 25 % sea water. All incubation salinities were obtained by dilution of natural sea water (collected at the same time as the crabs from Greta Beach) with deionised water. The osmolarities of samples for all salinity concentrations were subsequently measured using a vapour pressure osmometer (VAPRO, 5520, Wescor ELItech, South Logan, UT, USA) and found to have osmolarities of 1073, 797, 522, and 274 mmoL.kg-1 respectively. Ambient temperature was maintained at 25 °C. Video acquisition and analysis The microtiter plate was loaded into the LabEmbryoCam, an opensource instrument for timelapse imaging of aquatic embryos. In brief, the LabEmbryoCam incorporates a macro zoom lens (8 X macro zoom lens, with 4 X and 2 X front converters, TS-93002NI, Sugitoh, Japan), connected to a 12MP camera (Raspberry Pi HQ camera, Raspberry Pi Foundation, UK) and darkfield illumination (2 inch LuMini LED ring, Sparkfun, USA), mounted on a robotic X, Y and Z motorised stage system (Tills et al., 2023). Time lapse recordings were acquired for each embryo (1024 x 768 pixels, 30 frames.s-1, 8-bit depth, mag = 200 x, duration = 20 sec) every hour for a 24 h period. Each recording was examined visually and whether (a) there was a heartbeat, (b) hatching had occurred and/or (c) any appendages were moving was recorded. Heart rate was quantified using HeartCV, an open-source Python package for automated measurement of heart rate and heart rate variability that integrates automated localisation of cardiac activity (Ibbini et al., 2022). References Ibbini, Z., Spicer, J. I., Truebano, M., Bishop, J. and Tills, O. (2022). HeartCV: a tool for transferable, automated measurement of heart rate and heart rate variability in transparent animals. J. Exp. Biol. 225, jeb244729. doi:10.1242/jeb.244729 Tills, O., Holmes, L. A., Quinn, E., Everett, T., Truebano, M. and Spicer, J. I. (2023). Phenomics enables measurement of complex responses of developing animals to global environmental drivers. Sci. Total Environ. 858. doi:10.1016/j.scitotenv.2022.159555
Date made available29 Feb 2024
PublisherZENODO

Data Monitor categories

  • salinity
  • land crab
  • Developmental biology
  • embryo
  • hatchling

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