Fig. 1

Design of experiment using a type B conspecific cross. Gametes were collected by dissection from Type B specimens taken from the wild, and sperm of one individual used to fertile eggs of another. At 8 h post fertilization, half of the embryos were exposed to 26.5 ºC for 1 h and then reared at 17 ºC until they settled, metamorphosed and started feeding, whereas the other half were reared at 17 ºC without the temperature shock. Juveniles of both batches were then transferred to a marina and cultured side-by-side. After maturing in the marina, oocytes were collected from one heat-shocked and one non-shocked (control) individual for single-cell sequencing (scRNA-seq). NP, proportion of juveniles showing normal development at hatching. A red square indicates NP after heat shock, and a white square indicates without thermal stress