Abstract:

Laboratory feeding experiments of benthic ctenophores (Vallicula multiformis and Coeloplana waltoni) capturing and ingesting eggs and larvae of Coryphaena hippurus. Eggs, newly-hatched larvae, and zooplankton were offered to benthic ctenophores in separate timed (2 hr.) trials. Capture rates and behavioral feeding responses were determined in all trials.

Suggested Citation:

Glynn, Peter J., Vanderwoude, Jeongran. 2018. Ctenophore predators of dolphinfish (Coryphaena hippurus) eggs and larvae. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7NS0SD4

Purpose:

To determine if two ctenophore species were capable of capturing and ingesting dolphinfish eggs and larvae.

Data Parameters and Units:

predator prey size measurements.xlsx: Predator (Coeloplana waltoni, Eunicea succinea, or Vallicula multiformus), Prey (zooplankton, C. hippurus eggs, or C. hippurus larvae), Size (mm) The measurements in the this file relate to the columns in Tables S1 and S2 labeled “Pred/Prey Size (mm).” The spreadsheet gives the raw data for predator (Coeloplana, Vallicula, Eunicea) and prey (dolphinfish eggs & larvae, zooplankton) sizes. This is translated to a predator/ prey size ratio in Tables S1 and S2. The measurements are combined from all four trials (experimental 1 and 2, control 1 and 2). Table 1.xlsx: Coeloplana waltoni individual capture rates Prey (Mesozooplankton, C. hippurus eggs, or C. hippurus larvae), Trial (includes number and predator species), C.w. (Coeloplana waltoni), E.s. (Eunicea succinea), Percent loss (%), Total number of prey offered (per 50 mL), Loss per individual predator (per 2 hrs), Loss per individual predator (per day) Table 2.xlsx: Vallicula multiformis individual capture rates Prey (Mesozooplankton, C. hippurus eggs, or C. hippurus larvae), Trial number, Predator (Vallicula multiformis), Percent loss (%), Total number of prey offered (per 50 mL), Loss per individual predator (per 2 hrs), Loss per individual predator (per day) Table S1.xlsx: Coeloplana waltoni feeding trials and capture behavior of prey Prey (Zooplankton, C. hippurus eggs, or C. hippurus larvae), Trial (number, experimental or control, species), C.w. (Coeloplana waltoni), E.s. (Eunicea succinea), C.h. (Coryphaena hippurus), zplk (mesozooplankton), Date (DD-MMM-YY), Number of predators (per L), Initial prey density (number per mL), Final prey density (number per mL), Percent loss (%), Predator size (mm), Prey size (mm), Standard deviation, Observations Note: Mean maximum body dimensions (SD in parentheses). Table S2.xlsx: Vallicula multiformis feeding trials and capture behavior of prey Prey (Zooplankton, C. hippurus eggs, or C. hippurus larvae), Trial (number, experimental or control, species), V.m. (Vallicula multiformis), H.t. (Halimeda tuna), C.h. (Coryphaena hippurus), zplk/zpk (mesozooplankton), Date (DD-MMM-YY), Number of predators (per L), Initial prey density (number per mL), Final prey density (number per mL), Percent loss (%), Predator size (mm), Prey size (mm), Standard deviation, Observations Note: Mean maximum body dimensions (SD in parentheses).

Methods:

Zooplankton were collected in the field off the RSMAS dock in Virginia Key, Miami, Florida during daylight hours (May-July 2017). A plankton tow net with 64-micrometer mesh and a quarter-meter diameter opening was used for collections. Percent loss was determined by subtracting the control (focus predator absent) prey density losses from the experimental prey density losses All specimens of prey (zooplankton, dolphinfish eggs & larvae) were subsampled. We used 50 eggs/ or larvae each trial, which were randomly chosen from a stock of hundreds of larvae/ eggs. Out of these 50 specimens, 20 were measured (before the experiment) to obtain an average value for prey size with standard deviation. Experimental trials contain ctenophore predator, host substrate, and prey. Control trials contain host substrate and prey. Prey densities calculated from total number of zooplankton counted in 50 mL subsamples, which were introduced to the beakers containing 950 mL of seawater each, totaling 1 L for the experimental trials. To convert no. mL⁻¹ to no.L⁻¹, multiply by 0.05.

Individual Files: