Two follistatin-like 1 homologs are differentially expressed in adult tissues and during embryogenesis in grass carp ( Ctenopharyngodon idellus )

•We investigated fstl (follistatin-like) 1a and -b in grass carp.•Fstl1a and -b share 83% sequence identity but low similarity with Fst1 and -b.•The fstl1s were widely, differentially expressed in adult tissues and embryos.•Treatment with hGH, starvation and refeeding altered fstl1a and -b expression.•The two fstl1s may play important, diverse roles in grass carp development.