A lazy foodie that is unexpectedly beautiful
Blackfoot paua(Haliotis iris), belongs to the genus Haliotis in the family Haliotidae, order Archaeogastropoda. If you have already encountered it at the dinner table, surely its broad, jet-black foot left a deep impression on you. But did you know that in order to come before you, they crossed the equator, traveling at least11000 km. To repay this precious bond, perhaps we should learn a little more about it beyond its taste.
The shell of the blackfoot paua. Image: Eddie Hardy / gastropods.com
A lazy foodie
New Zealand, the beautiful island nation in the South Pacific, is the homeland of the blackfoot paua. Compared with the yellowfoot paua H. australis, which is also distributed in New Zealand, the blackfoot paua can be considered a very lazy foodie.
The blackfoot paua often feeds along the shore on seaweed brought by ocean currents and tides, and it seemsnot to be a picky eater; theyhardly move from one spot, as the currents continuously bring seaweed to them. The yellowfoot paua, by contrast, seems to have somewhat higher standards for food, actively seeking out seaweed attached to rocks.
The blackfoot paua's feeding strategy of hardly moving from one spot reminds me of this sloth. Image: lckubo / youtube
Although the blackfoot paua does not like to move around much, they are not randomly distributed along the coast; instead, there are relatively clear-cut boundaries -- juveniles with a shell length of less than 70mm tend to choose crevices in rocks or under stones in the mid-littoral zone as their"children's playground", while adults tend to choose the low littoral zone as their"adult world"。
This choice is related to the blackfoot paua's reaction to light. When individuals are smaller, they generally exhibitphotophobia, which makes them seek shelter to avoid predation; slightly larger individuals are less sensitive to light. The blackfoot paua alsoknows the art of lying dormant。
Adult blackfoot paua in the wild. Image: New Zealand Marine Studies Centre
The growth of the blackfoot paua not only means they must step into the "adult world" in the low littoral zone, but also means they need to take on the heavy responsibility of reproduction. They reach sexual maturity at about 4 years of age, when the shell length is about 60mm.
Late summer and early autumn are their breeding season. Mature females and males release gametes, and fertilization and hatching are completed in seawater. The newly hatchedlarvaedrift in the water; if they are lucky enough not to be dispersed by ocean currents or eaten by predators that feed on plankton, then after about three days they can develop intojuvenile paua living on the bottom. They will continue to live on the rocky seabed of shallow waters and grow vigorously.
The most beautiful paua
The blackfoot paua is hailed as the most beautiful paua in the world, yet you may feel that no matter how you look at them, they appear rather ordinary. Don't worry -- its beauty is merely hidden. Let us uncover it properly together.
If you have dealt with paua, you may know that a paua's body consists of a broad shell and the body beneath the shell. Within the body,the muscular foottakes up most of the volume, and this is also our main edible part. Lifting their broad foot, we can see the pearlescent inner surface of the shell -- this is the paua'snacre。
The foot of a paua. Image: geminiconnect.com
Top: the shell of the disk abalone; bottom: the shell of the variously colored abalone. Image: H. Zell / Wikimedia
The inner surface of the blackfoot paua's shell is usuallyinterwoven with multiple colors such as blue, red and green, just like a rainbow. Its specific epithet iris means "rainbow" in Greek, precisely to describe their brilliantly colorful shells.
The shell of the blackfoot paua. Image: H. Zell / Wikimedia
If the most beautiful paua were judged solely by the rainbow hues of the shell's inner surface, it might be hard to convince everyone. Let us continue to uncover the beauty of the blackfoot paua, though this time we may need to put more effort into its surface.
The outer shell of the blackfoot paua is oftenreddish-brown, which isprotective colorationto blend itself into the environment. If this outer coat is polished away, their beautiful side will truly be revealed:after polishing, the shell of the blackfoot paua displaysa blue-green metallic luster. If the alternating pearlescent sheen of blue, red and green on the inner surface is like the colors of a rainbow, then the polished shell surface resembles nothing so much as the mysterious and unknown universe.
A polished blackfoot paua shell. Image: J J Richards
The price of beauty
Those most familiar with the blackfoot paua must surely be the Maori, who have lived alongside them for thousands of years.The Maorinot only eat the meat of the blackfoot paua but also craft its shell into works of art. In Maori wood carvings, blackfoot paua shell is often used to make the eyes of the figures. They believe that these shells, as brilliant as the starry sky,represent the eyes of ancestors gazing down from the night sky。
Maori sculpture. Image: JShook / wikimedia; Barni1 / pixabay
In addition, some contemporary New Zealand jewelers also use blackfoot paua shell to make brooches, necklaces, earrings, bracelets, amulets, bracelets, pendants, rings and othermodern jewelry。
The beautiful shell of the blackfoot paua gives it value beyond food, yet this beauty sometimes also means danger. As one of the larger species in the genus Haliotis, theydo not grow quickly. Therefore, to balance the contradiction between the blackfoot paua's population and human exploitation, the New Zealand government has established a strict set of regulations: blackfoot paua may only be harvested byfree diving(without underwater breathing apparatus,using only a single breath and breath-holdingto carry outdiving activities).
Moreover, the New Zealand government has also set limits on the harvest size of the blackfoot paua: the legal harvest size is 125mm, and the daily quota per person is only 10. To reach this size, a blackfoot paua needs at least 7 or 8 years.
Some divers carry a small bottle of oxygen for emergencies; if the oxygen is intact when they come ashore, this is not considered a violation of relevant laws. Image: Ken Bailey / californiaoutdoorsqas.com
This regulation may seem harsh, but in earlier times, humans also harvested paua using this method. The earliest fishery record of paua is from Japan in 425 AD, when a diver named Osahi had already been using free diving to harvest paua, and also recorded werethe risks of diving work. On September 12, 425 AD, Osahi went diving to harvest paua, and his only protective measure wasa rope tied to his wrist. This time Osahi seemed to stay underwater a little too long; his companions on the boat realized something was wrong and hurriedly pulled him up from below, but it was too late. Osahi was gone, but his hands still kept the posture of holding something. In his hands was a giant paua.
In early harvesting, that rope tied to the wrist and held by a companion in the boat was the lifeline. Image: cdlib.org
Thanks to today's convenient international trade, the blackfoot paua, the orange roughy (Hoplostethus atlanticus), the Patagonian toothfish (Patagonotothen ramsayi), the Brazilian butterfish (Stromateus brasiliensis) and so on -- theseexotic wonders we once could hardly reach-- now increasingly encounter us at the dinner table.
The orange roughy, the Patagonian toothfish, and the Brazilian butterfish from 18800 km away. Image: SeaFIC & INIDEP & Vaske Jr., T. / Fishbase
When we meet them, besides tasting the flavors accumulated for them by the unique phenology of their growing places, aren't those stories that have traveled from afar also a delicacy in themselves?
This article is the 239th article in the 4th year of the Species Calendar, from Species Calendar author @Sundayhao.