Critter of the Week: The prickly king crab
The prickly king crab, Paralomis zealandica, is a member of the family Lithodidae, a mainly deepwater crustacean group that is probably better known by many people for its tasty leg meat.
The prickly king crab is not a quota species in New Zealand, but some of its relations are regulated under the quota management system with some small commercial catches being made each year.
These are not the largest of the New Zealand king crabs, that title is held by Lithodes aotearoa, which can have up to a 1.3 m leg span. Paralomis zealandica can reach up to 13 cm across its carapace. However, Paralomis zealandica is one of the most widely distributed species in the genus, distributed in southern New Zealand waters from the Chatham Rise down to the Campbell and Bounty Plateaus from 254–1212 m, but normally from 550–650 m.
There are a lot of king crabs with prickly carapaces, but P. zealandica can be distinguished from other species in New Zealand waters by its thick covering of strong upright spines all over, including on its abdomen and along its legs and claws. The rostrum, or the bit sticking up over its eyes, has three short, strong and sharp spines.
Not a true crab
In the below top-down shot of a smaller juvenile specimen you can count three pairs of walking legs (pereopods) plus the claws (chelipeds). Interestingly, the king crabs are actually not true crabs and their fourth pair of walking legs are greatly reduced like a hermit crab, their closer crabby-like relations.
Further information and references
Ahyong S. T. (2010) The marine fauna of New Zealand: King crabs of New Zealand, Australia and the Ross Sea (Crustacea: Decapoda: Lithodidae). NIWA Biodiversity Memoir 123. Order a hard copy here.
Pevious posts about the Lithodidae family and other New Zealand king crab species:
Kamba wa kifalme wa mti wa mti, Paralamis zealandica, ni mshiriki wa familia ya Lithodidae, kikundi cha krustaceans hasa ya maji ya kina ambayo labda inajulikana zaidi na watu wengi kwa nyama yake ya miguu yenye ladha. Panya wa kifalme wa thorny sio aina ya kiasi katika New Zealand, lakini baadhi ya mahusiano yake yanadhibitiwa chini ya mfumo wa usimamizi wa kiasi na baadhi ya samaki wadogo wa kibiashara wanaofanywa kila mwaka. Lithodes aotearoa ni aina ya kamba wa New Zealand anayeitwa king crab na kwa muda mrefu anaweza kufikia urefu wa mita 1.3. Paralyssa zealandica inaweza kufikia urefu wa sentimita 13 kwenye kifuniko chake. Kizazi cha P. zealandica ni aina ya krab wa kifalme, ambayo huenea katika maji ya kusini mwa New Zealand kutoka Chatham Rise hadi Campbell na Bounty Plateaus kutoka 254-1212 m, lakini kwa kawaida kutoka 550-1252 m. Kuna krab nyingi za kifalme na carapace ya thorny, lakini P. zealandica inaweza kutofautishwa na spishi nyingine katika maji ya New Zealand kwa kifuniko chake kikubwa cha miiba mikali. Rostrum, au sehemu inayoinuka juu ya macho yake, ina miiba mitatu mifupi, yenye nguvu na mikali. Katika picha iliyo hapa chini ya picha ya juu-chini ya sampuli ndogo ya vijana unaweza kuhesabu jozi tatu za miguu ya kutembea (pereopods) pamoja na makucha (chelipeds). Kwa kushangaza, king crabs sio crabs halisi na jozi yao ya nne ya miguu ya kutembea imepunguzwa sana kama crab hermit, jamaa zao wa karibu kama crab. Ayewung S.T. (2010) Fauna ya baharini ya New Zealand: King crabs ya New Zealand, Australia na Bahari ya Ross (Crustacea: Decapoda: Lithodidae). NIWA Biodiversity Memoir 123 Agiza nakala iliyochapishwa hapa. Machapisho ya zamani kuhusu familia ya Lithodidae na spishi nyingine za kamba wa mfalme wa New Zealand: