FISH FILLIPS

Fish display highlights Kiwi North’s underwater world, writes

FISH DISPLAY an array of adaptive features to survive their underwater worlds, and this is highlighted in Kiwi North’s Life And Tides marine exhibition, which is visually stunning and full of research to educate inquiring minds.

As one example, the exhibition displays a life-sized re-creation of a moonfish (opah) — the only known warm-blooded fish. Most fish have body temperatures matching their surrounding waters, and are therefore cold-blooded.

However, the moonfish found an ingenious way to adapt in the chilly depths millions of years ago, by raising its body temperature to a constant 5C warmer than its ocean surrounds.

This makes the moonfish a true marvel of evolution: by producing heat through the constant flapping of wing-like pectoral fins, it minimises heat loss through blood vessels in its gills.

The two sets of vessels are tightly bundled against each other, so that the incoming blood vessels warm up the outgoing blood before it goes anywhere else. This unique heat exchange within the gills allows the fish’s entire body to maintain an elevated temperature, known as endothermy.

Unfortunately, the world’s oceans are heating up, and in a sad irony the remarkable moonfish will soon face survival challenges, due to its warmblooded nature.

To avoid overheating, the moonfish may exhibit some behavioural changes such as migrating to deeper, cooler, or more shaded waters; it may also have to adjust its prey preferences or feeding locations due to the increased temperature changes. Additionally, it may increase its fin-flapping to dissipate excess heat and regulate its body temperature.

Its survival depends upon its ability to quickly adapt to new temperature conditions, and to maintain its warmth without overheating.

An increasing array of marine creatures are endangered, and one of these is the Maui dolphin, an endemic species of Aotearoa, with only 55 left.

The taxidermied Maui dolphin that you will see in Kiwi North’s Life and Tides exhibition was created by taking a mould off a deceased Maui dolphin found on a beach about 40 years ago.

The preserved form of this rare animal allows us to get a close look at the animal’s size and form, and to appreciate its fragility and vulnerability — in this case, skilled taxidermy provides a rare glimpse of a marine animal that most of us will never see in our lifetime, while simultaneously highlighting the dire need for its protection.

Museum visitors are encouraged to take part in a visual petition to help the Maui Dolphin’s plight.

Taxidermy is incorporated in further innovative ways throughout the exhibition, revealing rare creatures that have become stranded on our shores through some strange fluke of nature, such as the magnificent Indo-Pacific sailfish, or the mysterious crested bandfish, which is still a little-known species. Run your hand over the taxidermy touch-plates that were especially developed for this exhibition to enhance people’s understanding of the incredible variations of fish textures, from the smooth-skinned species that glide through water, to the slower types that hover in their protective bony amour.

The potbellied seahorse is yet another of these incredibly designed sea creatures, with its distinctive long-snouted horse-like head, a pot-bellied body that is covered in protective bony cartilage-plates, and a longcoiling square tail that is as strong and flexible as a human hand.

When scientists closely examined this tail, they found that the overlapping squareshaped segments provided better armour and a greater gripping capacity than a cylindrical tail. This biological discovery is an inspiration in engineering, which is being investigated and could lead to building better robots and medical devices.

Seahorses are the only animal species in which the male gets pregnant and gives birth to the babies. These seahorse dads carry their babies in a pouch, a bit like kangaroos do, and give birth to live young.

If you have never seen a live pot-bellied sea horse, there is an opportunity to do so at our curator’s talk and seahorse encounter coming up at Kiwi North this month.

It is suitable for every age and is included with Kiwi North’s general admission. This event will be held at Kiwi North on Saturday April 27 at 9am. Seating is limited to this event, so bookings are essential at: bookings@kiwinorth.co.nz

■ Visit Kiwi North’s website for further details on all Life and Tides activities during the school holidays. at Kiwi North is a museum assistant

From top left, the moonfish is a marvel of evolution; children explore the

exhibition; creatures from the Northland coast are featured in the exhibition.