Marine Life

 The Otago Peninsula is renowned internationally for its abundance of incredible sub-Antarctic wildlife.  Sir David Bellamy, once commented “in my opinion, the Otago Peninsula is the finest example of eco-tourism in the world” Seals and Sea Lions come ashore to lie on the rocks of the Otago Peninsula.  At Taiaroa Head, the Royal Albatross has established its only land-based breeding colony in the world. 


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    Fish and Mammals

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  Fish and Mammals | Invertebrates 

Pleurobranch - Berthella medietas  

Pleurobranch - Berthella Medietas

Berthella medietas



A small pleurobranch with a thick dull cream coloured mantle, only seen by night at Aramoana and other parts of the Otago Harbour.

Size's up to 6cm in length have been seen.

Pillbox crab  

Pillbox Crab

Halicarcinus sp.



This very small crab has an angular flat shape carapace which narrows towards the head. It varies in colour from yellow, green and orange to black. Is commonly seen walking around the intertidal zone.

Carapace width can be up to 20mm .

Octopus (smaller)  

Octopus (Smaller)

Octopus huttoni



The smaller octopus - octopus huttoni are usually seen about the size of your fist, and tend to be more frequently sighted on night dives as they emerge to feed. They tend to be more fearful compared to other octopus, perhaps realising their size makes them an easy meal for predators. These small octopus make homes out of almost anything, old cans, and bottles that have been discarded will often hold octopus.

Up to 57cm in total length.

Octopus (Larger)  

Octopus (Larger)

Pinnoctopus cordiformis





Octopus are masters of disguise and are easy to miss. Their ability to change colour and shape means they can be very deceiving. Individual octopus tend to have different personality's, some will want to curiously crawl up your arm, while others shoot ink and slink away at first sight. The Pinnoctopus cordiformis (Wheke) is the most common octopus found locally, it can grow huge up to 2m in length and can be seen cruising the reef in search of crayfish, crabs and shellfish or found in it's dens which is identifiable by the empty shells of its prey surrounding the opening.

Lengths of up to 2m with arms out stretched.

Nudibranch - Spurilla drusilla  

Nudibranch - Spurilla Drusilla

Spurilla drusilla



They appear to be completely covered in cereta along their body, and have two tentacles on the front corners of their foot. They are commonly hidden under rocks in the low intertidal area and can be found in rock pools and the very shallows of dive sites around the coastline.

Grows up to 37mm long, but commonly smaller in the south of New Zealand.

Nudibranch - Trapania rudmani  

Nudibranch - Trapania Rudmani

Trapania rudmani



This small active nudibranch is rarely seen, it is found typically amongst encrusting organisms on vertical walls. They have been spotted at both Aramoana and Wellers rock, possibly sometimes confused with a tiny golden-margin nudibranch on first glance, but the four finger like processes which each have a a yellow stripe on the outside are unmistakable.

May grow up to 24mm in length.

Nudibranch - Janolus novozealandicus  

Nudibranch - Janolus Novozealandicus

Janolus novozealandicus



It's translucent body has broken white marking along its length, and along the tail is a white mid-line. Its cerata are also translucent and inside part of it's digestive system is able to be seen. It is encountered in channel mouths and harbour entrys but it is rarely seen, throughout our dive sites but has made appearances at Aramoana and Wellers Rock.

Lengths of up to 44mm can be reached.

Nudibranch - Hoplodoris nodulosa  

Nudibranch - Hoplodoris Nodulosa

Hoplodoris nodulosa



Sometimes it is confused with a juvenile wellington nudibranch because of its pustules along the body. However it is far smaller and the colour is broken between the mantle and the pustules. Because of their likeness for muddy shell rubble and sheltered habitats they are commonly seen at Wellers rock along the muddy bottom on small red seaweeds and other low lying plants, and also make frequent appearances at Aramoana.

Lengths of up to 42mm can be reached.

Mantis shrimp  

Mantis Shrimp

Squilla armata


Thumb splitters



The mantis shrimp is named after the similarity between itself and the insect praying mantis. Our mantis shrimp - Squilla armata, which is the only species in New Zealand, is a spearer they prefer the meat of softer animals that can easily be sliced or snagged. Commonly seen at our local dive site Wellers rock, they are found in the shallows having built small tunneling homes they appear to be perfect circles tunneled straight down in the silt. If you move slowly you will see their small heads gaping at you from their home before they disappear as you get close. They rarely leave their home except to feed and relocate so are not commonly seen.They are also sometimes referred to as thumb splitters because of the injuries they cause when handled inappropriately

Sizes can reach up to 15cm in length.

Mottled brittle star  

Mottled Brittle Star

Ophionereis fasciata



The mottled brittle star does not move by using it's tube feet but instead walks on its arms to move about quickly. It is infrequently seen in the open because it lives underneath stones and inside cavities from which it extends its arms to feed on plankton and detritus. Their small arms can be seen waving about on invertebrate encrusted areas such as Aramoana.

Arm spans of up to 15 - 20cm have been seen, but they are commony much smaller.