Eurynolambrus australis
| Triangle crab | |
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| Species: | E. australis
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| Eurynolambrus australis H. Milne Edwards & Lucas, 1841
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Eurynolambrus australis, commonly known as the triangle crab, and by its Māori name riangi, is a small species of crab that is widespread throughout New Zealand.[1][2]
Habitat[edit]
E. australis is commonly found among stones and under rocks in the lower and sub tidal region of the intertidal zone where it can reach depths of up to 80 m.[1][3][4] It is often found in rock pools with coralline turf.[1]
Description[edit]
Adults are between 50 – 65 mm in size with a broad triangle-shaped carapace that extends over the leg base. This can be white, pink or bright red in colour with white, grey-brown, and yellow markings.[1][3] Legs are short and flat with irregular crests. Their colour can be mottled with orange, dark red and white. They fold neatly underneath the carapace. Chelipeds have a rough and pitted surface and curve inwards. They are purple in colour with a white inner surface. The antennules are usually a pale yellow colour. The eyestalks are red.[2]
Behaviour & Diet[edit]
The triangle crab is a scavenger feeder.[5] It feeds mostly on coralline alga, which is thought to cause the bright red pigmentation on its shell.[1] It also feeds on red and green algae, as well as amphipods, isopods and decapods.[4]
It is a cryptic species that defends itself from predation with camouflage. Some divers and amateur observers suggest it is more active at night and may be nocturnal.[6][7]
References[edit]
- ^ a b c d e Carson, Sally; Morris, Rod. Collins Field Guide to the New Zealand Seashore.
- ^ a b Wilkens, Serena L.; Ahyong, Shane T. (2015). Coastal Crabs: A Guide to the Crabs of New Zealand. NIWA.
- ^ a b Bennett, Edward William (1964). The marine fauna of New Zealand: Crustacea Brachyura (PDF). RE Owen, Government printer.
- ^ a b McLay, Colin L.; Woods, Chris M. C. (1996-12-20). "Diet and cryptic colouration of the crab Eurynolambrus australis (Brachyura: Majidae) at Kaikoura, New Zealand". Crustacean Research. 25: 34–43. doi:10.18353/crustacea.25.0_34. ISSN 0287-3478.
- ^ "Crab, Triangle". www.marinelife.ac.nz. Retrieved 2019-06-08.
- ^ "Cliff dwellers of the Poor Knights". www.seafriends.org.nz. Retrieved 2019-06-08.
- ^ "Triangle Crab". diveotago.co.nz. Retrieved 2019-06-08.