Singular or plural after "species"

[Nordic Bill]

Which would be the more correct here?:
"Some species of spider can walk on water."
or
"Some species of spiders can walk on water."
Since there is really only one type of creature known as the spider (despite its many species), I would figure that it would remain singular in this case.
Thanks,
Bill

[Casiopea]

Consider,

Some species of the type Spider . . .
Some species of spiders . . .

[Nordic Bill]

My Gosh - that one comes as a surprise. I was so certain it would be "spider" here.

Thanks for letting me know.

Rgs,
Bill