Complex sentence: Highfin carpsuckers breed when temperatures are around 17 ° C. In Tennessee, these temperatures usually occur mid-May, though Highfins have been known to mate anywhere from April to June.
Split into simpler sentences: Highfin carpsuckers breed when temperatures are around 17 ° C. In Tennessee that usually occurs in mid-May. But have been known to breed anywhere from April to June.