種数 is read as しゅすう (shusuu) and means genus.
しゅすう
shusuu
すうしゅ
several varieties
しゅもく
item
しゅるい
counter for kinds, species, etc.
くさぐさ
various
しゅじゅ
しゅぞく
stellar population (i.e. population I, II and III)
しゅし
seed
たね
paternal blood
しゅべつ
classification
たねつけ
mating
たねうま
studhorse
しゅぶんか
speciation