Killing a katipo spider could now result in a fine of $100,000 or even a prison sentence.
Under changes to the Wildlife Act announced on Thursday by Conservation Minister Kate Wilkinson, 12 species, including katipo, giant weta and whale sharks, have had their protection status beefed up.
Others, including several introduced species, have had their protection status downgraded.
Ms Wilkinson says the changes, which affect more than 50 species, take a pragmatic approach.
The grey teal duck still has absolute protection, but the penalty for shooting one by mistake has been cut from $100,000 to $5000.
Changes seen as not going far enough
The Royal Forest & Bird Protection Society of New Zealand says the move by the Government to increase protection for some wildlife, will not be effective unless their habitats are also protected.
Forest & Bird says that while the species may be protected, their habitats are not.