Materials and Methods
Spawning, larval rearing,
settlement and symbiont infection
Gravid adult corals of the species Acropora spathulata were
collected from one reef in the far north of the Great Barrier Reef
(Tijou, far northern GBR; 13°10’44.0”S, 143°56’54.6”E, permit
G16/38488.1) and one reef in the central GBR (Backnumbers, central GBR;
18°30’49.8”S, 147°09’10.7”E, permit G12/35236.1) and brought back to the
National Sea Simulator (SeaSim) for coral spawning in November 2017 as
outlined in (Quigley et al., 2020). Briefly, on the night of spawning
the separated eggs and sperm from three far northern colonies were mixed
with those of three central colonies, resulting in larvae from 30
distinct familial crosses that were raised in 27.5°C ultrafiltered,
flow-through seawater (see Table 1 for pedigree and parental colony
designations). Only five families were available at the time of larval
settlement and used to produce recruits (hereafter referred to as
juveniles given measurements were taken after 70 days of development).
Here we focus on those five familial crosses sequenced at both the
larval stage (27.5°C) and the juvenile stage (27.5°C and 31°C). These
crosses include three produced from two parents sourced from the warm
far northern reef (WW1, WW2, WW3), one cross with a warm dam and cool
sire (WC) and one with a cool dam and warm sire (CW). Aposymbiotic
juveniles were infected with Symbiodinium tridacnidorum ,Cladocopium goreaui , and Durusdinium trenchii with
cultured material obtained from the AIMS Symbiont Culture Facility
(further details in Quigley et al., 2020). Full details of the
collection, environmental parameters of each location, permits,
spawning, larval and juvenile rearing, and symbiosis establishment can
be found in Quigley et al., 2020.
Briefly,
symbiosis establishment in coral juveniles was performed by adding
1x105 ml-1of one of the three
cultured symbiont strains separately to each juvenile tank (n = 3
replicate tanks per culture), suspending the flow to allow for contact
between corals and symbionts, and repeating one further time until
infection was confirmed with microscopy.