Climate change and urchin fertilisation and the effect on the growth rate of juvenile Abatus sp.

Brief description

The effect of pH, temperature and sperm concentration on the fertilisation of Sterechinus neumayeri was investigated. Adult Sterechinus neumayeri were collected from Ellis Fjord Narrows between December and January 2011-12 and held in the Ecotox Field Aquarium Module until used. Between 3-4 male and female individuals were spawned using 0.5M KCl and gametes were collected separately before being fertilised in treatment.

The data set shows the percentage of fertilised and non-fertilised eggs of Sterechinus neumayeri scored at 20h post-fertilisation. Eggs were fertilised in various combinations of pH, temperature and sperm concentration treatments (pH: 8.0 (Control), 7.8 and 7.6; Temperature: 1 degrees C (Control), 3 degrees C and 5 degrees C; Sperm concentration (sperm:egg ratio): 1000:1 (Control), 750:1, 250: 1, 50:1 and 5:1). At 20h post fertilisation, 5 ml aliquot was removed from fertilisation vials and eggs were counted and determined if they were fertilised or not. Seawater parameters of treatments were measured at the start and end of the experiment.

Detailed information of the spreadsheets are as follows:
Seawater Parameters column headings:
Temperature - measured in degrees C , shows the temperature treatments used
pH - shows the pH levels used
Subheading pH - pH level measured for the day using NIST certified buffers
Subheading MV - pH level measured for the day in millivolts
Subheading Total pH - total pH level in seawater obtained from MV measurements
Subheading Temp - temperature of seawater measured for the day

1 deg C column headings:
Experiment - number of experiments
pH - shows the pH for each treatment
Sperm Concentration - shows the sperm concentration used for each treatment in a egg:sperm ratio
Rep - shows the number of replicates per experiment
Unfertilised eggs - eggs without visible fertilisation envelope and no cleavage after 20h
Fertilised eggs - eggs with visible fertilisation envelope and/or cleavage after 20h
Fertilised deformed eggs - eggs with visible fertilisation envelope but deformed
Total eggs - total eggs scored (whether fertilised or unfertilised)
% Fertilised - fertilised eggs (deformed and non-deformed)/Total eggs

3 deg C and 5 deg C have the same column headings as 1 deg C.

AAS3134 Abatus sp Growth Experiment Davis 2011-12:
The effect of pH and temperature on the growth rate of juvenile Abatus ingens and Abatus shackletoni were investigated. Adult Abatus were collected off Airport Beach in waters 4-5m depth.

Data set shows the growth rate of juveniles of Abatus ingens and Abatus shackletoni after a 4-week exposure to various combinations of pH and temperature. Juveniles of each species was removed from maternal pouches and photographed on the oral side before being exposed to combinations of pH (8.0 (Control), 7.8 and 7.6) and temperature (-1 degrees C (Control) and 1 degrees C) levels. They were incubated in treatments for 4 weeks before being removed and rephotographed. The lengths of 10 spines per juvenile were measured in the pre- and post-experiment photographs using ImageJ and the difference calculated to get a growth rate per juvenile. Seawater parameters of treatments were measured at the beginning of the experiment and subsequently once a day until the end of the experiment.

Detailed information of the spreadsheets are as follows:

A ingens (pre-exp) i.e. juvenile Abatus ingens spine lengths measured before exposure to experimental treatments. Column headings are:
Spine number and length (mm): Length of each spine (1 - 10) measured per juvenile in mm.
R1 - R12: Number of juveniles

A ingens (post-exp) i.e. juvenile Abatus ingens spine lengths measured after 4-week exposure to experimental treatments. Column headings are identical to the above.

A shackletoni (pre-exp) i.e. juvenile Abatus shackletoni spine lengths measured before exposure to experimental treatments. Column headings are identical to the above.

A shackletoni (post-exp) i.e. juvenile Abatus shackletoni spine lengths measured after 4-week exposure to experimental treatments. Column headings are identical to the above.

2011-12 Aquarium pH and temp main headings show different treatment parameters. Column sub-headings are:
Date - Date of measured seawater parameters
Salinity - salinity of seawater measured
Ppm - Amount of CO2 gas pumped into water recorded in parts per million
pH - measured pH of seawater using NIST-certified buffers
MV - pH of seawater recorded in millivolts
Total pH - total pH of seawater derived from MV
Temp - Temperature of seawater measured in degrees C.