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The katipo is an increasingly rare venomous spider native to New Zealand. In 2010, they were declared endangered, and protected by the government. Its scientific genus and species name is Latrodectus katipo. Like other animals endemic to the island nation, the spider shares characteristics with other related species such as the North American and European “black widows” but has evolved uniquely to isolation and adaptation. Its common name is a contraction of New Zealand’s native Maori words kakati meaning “to sting,” and po for “night.”
They are most closely related to the Australian redback spider, and a common English name for them is the New Zealand redback spider. It has also been demonstrated that a male Australian redback can mate with a female katipo to produce hybrid offspring. When the reverse is attempted however, the male katipo is immediately attacked and eaten. The two were once classified as simple subspecies, but significant anatomical and behavioral differences dictated their separate designations.
The same confusion of classification occurred between katipo living in northern New Zealand and those which inhabit its southern island. The female of the latter has an orange or red geometric stripe, thinly outlined in white, down the center back of its round, black abdomen. Females of the northern island do not have this marking, and were once separately designated as the black katipo. This difference in color, however, was proven to be the simple result of a respective average temperature difference during an egg’s incubation period. Due to colder temperatures, they are absent, unable to breed, in the southernmost coastal regions of New Zealand.
Male adult katipo were also once assumed and classified as an entirely different species. They are about one-sixth the size of a female. The head and thorax are brown. The abdomen is white. Its back is marked with a series of red-orange diamonds, outlined by irregular black lines.
The adult female is a relatively medium-sized spider, about 1.3 inches (about 3.3 cm) in diameter inclusive of her legs. Her silky, velvet-black abdomen is proportionately over sized. Its underside is also marked by a triangularly shaped red patch.
The restricted habitat of the katipo is a unique, very narrow niche — coastal sand dunes. They spin their lairs, a haphazard tangle of adhesive webbing, by anchoring it to seashore plants and debris on the dune’s leeward side. Crawling insects, many of them blown into the trap by onshore wind, are its main diet. When one is entrapped, it is quickly bitten with venom as well as sprayed with additional, immobilizing silk.
Its venom is a neurotoxin believed to be very similar in most species of its genus. Bitten humans will experience extreme pain, redness and swelling spread from the punctures. It generally persists for a few hours to one day. Uncommonly, if the venom spreads, symptoms can expand to include: vomiting, chest pain, headache and muscle tremor. Respiratory failure, seizures or a coma are extremely rare, as the anti-venom developed from the Australian redback can be administered as a preventative measure.