Deep sea yields rare sea creatures

NORFANZ research survey

Deep Sea Yields Rare Sea Creatures

30 May 2003

A fish that walks, a wonky-eyed squid, and two new genera of soft coral are just a few of the rare animals discovered during the NORFANZ research survey. NORFANZ is a joint four-week New Zealand-Australia venture exploring deepsea habitats from northern New Zealand to Lord Howe and Norfolk Islands and back.

The survey, jointly funded by New Zealand's Ministry of Fisheries and Australia's National Oceans Office, with scientific support from New Zealand's National Institute of Water & Atmospheric Research (NIWA) and Australia's Commonwealth Scientific & Industrial Research Organisation (CSIRO), is now in its third week.

The 24 scientists on board NIWA's deepsea research vessel Tangaroa are working around the clock to photograph and video the seafloor at depths between 200 and 1200 metres, and to collect samples and specimens. The fascinating finds are recorded in the scientists' daily diaries, posted on the website www.oceans.gov.au/norfanz.

The walking Coffinfish
On Day 14 trawls at 700m and 570m brought up the bizarre fish that walks, the Coffinfish.

These are flabby bottom-dwelling fishes that can walk along the seafloor on short leg-like fins. These fish can swallow large amounts of water to inflate themselves, presumably making it harder for predators to bite into them, and they often come up in trawl nets swollen into a ball. Coffinfish have a small lure on their head (like their anglerfish relatives), consisting of a short rod and a small glowing bulb at the tip which they use to lure prey. The eyes of the fresh fish are speckled with iridescent green, looking like a pair of spectacular opals. The animals found on the NORFANZ survey were about 20-30 cm long.

Coffinfish

Wonky-eyed jewel squid
The jewel squids are one of the strangest occupants of open-ocean waters. Firstly they have wonky eyes, the left eye is always much larger than the right. In some species the left eye is telescopic, while the smaller right eye is normal. These squids have a funny slant on life, literally. They hang at a 45° angle and use the huge eye to look up for passing prey. Meanwhile, the normal eye looks below for any signs of predators. The common name, jewel squid, comes from the scattering of small iridescent spots over the undersides of the body, head, and arms. These are tiny, directional light organs like tiny car headlights. When the squid is hanging at a 45° angle, all the light organs aim down and produce just enough light to cancel out the silhouette of the squid against the weak light from the surface above. Jewel squid can even adjust the lights for different depths or time of day. Jewel squid can float in mid water by filling their soft flesh with pockets of ammonia solution that is less dense than seawater and cancels out the weight of their muscles. They make these solutions out of their body wastes - urine is used as a buoyancy aid.

Jewel Squid

Two Spiked Dogfish double known numbers
Among the other exciting finds were two male specimens of an undescribed small species of shark. Known as spiked dogfish (genus Squalus), these two animals double the known number of specimens in the world. The largest was about 60 cm long. Research on related dogfish species elsewhere found that they can form large same-sex schools. The long narrow spines on the dorsal fins are characteristic of this species. Some species of dogfish with much thicker spines use the spines to wedge themselves under rock ledges. The long good condition of the spines in the NORFANZ species suggests a free-swimming lifestyle. There are poison glands at the base of spines. This new species is known only from this region.

Spiked Dogfish

Pacific Spookfish
One of the strangest finds was the Pacific Spookfish (Rhinochimaera pacifica), a strange cartilaginous fish which uses its long snout to scan over the seafloor for the electrical impulses of its prey which bury in the muddy seafloor, just like a metal detector. Like other chimaeras (such as ghost and elephant sharks), these animals lay horny egg cases in which their young are left to develop, potentially for up to a year.

Pacific Spookfish

Rare Eelpout
These small eel-like animals are not eels, they're actually related to blennies. Their name comes from their eel shape and big pouty lips. In the southern hemisphere, this family is represented by only a few small species, mainly from the deep sea. The bottom-living forms are very rare, there being only a handful of specimens in New Zealand collections and only one specimen in all of Australia's research collections. There is still very little known about these rare fish.

Eelpout

Two new genera of soft coral
Two important new discoveries were a couple of very small soft corals that are new to science. These are not just new species, these are so different from their nearest relatives that they are new genera as well. The first looks like small, bright purple spots on some fragments of sponge. Under magnification it can be seen that the spots are actually minute coral polyps; the white sclerites (the microscopic skeletal granules) can be seen scattered on the brightly coloured tissue.

The second new find consisted of strands of grey tissue forming a maze over a couple of small rocks. Most of the polyps have been worn off due to abrasion, but a few remain. They are about 5mm tall and 1mm thick. Under a microscope, the skeletal sclerites, which are made of calcium carbonate, show that this coral is very similar to only two other types of soft coral, and both of these have been found only in the North Atlantic Ocean and the Mediterranean Sea. This is the first record for the Pacific Ocean.

Voyage progress Halfway through the survey, the RV Tangaroa made landfall at Lord Howe Island, with some scientists joining the voyage and others leaving it. After leaving, the seafloor mapping team (swath mappers) spent several hours mapping the unchartered seafloor around nearby Ball's Pyramid (see below). The survey is due back in Wellington, New Zealand, on Saturday, 7 June.

For further information please contact:
Sarah Morton, Communications Specialist, Ministry of Fisheries
Telephone 04 494 2370
Katrina Haig, Public Affairs Officer, National Oceans Office
Telephone 0061 3 6221 5036

Ends.