orange roughy

Orange roughy is a white-fleshed fish, similar to cod, with a mild flavour, low fat content, and delicate texture. I use it to make Thai fish cakes, and I don't find it fresh in Toronto; I have to buy it frozen. That's because the main fishery for orange roughy is New Zealand, far from my home.

Orange roughy lives not on the surface waters, but in the cold dark depths of the ocean - as much as a mile down. Another interesting factoid I dug up is that they mature in their 30s and can live to be 150 years old or more! A fish! Apparently this is partly due to their habitat, which promotes slow growth and development. This, along with advances in trawling technology, also makes them susceptible to overfishing, and catches have fallen to a fraction of what was harvested a decade ago.

Slimehead?
This fish is part of the slimehead family, a status that made it unappealing to consumers. It wasn't until it enjoyed a name change that it became a delicacy, one worthy of seeking out. Be honest, you wouldn't even hold a slimehead in your hand, much less put a bite of one in your mouth, would you? Of course you wouldn't, and I wouldn't either.

description
The fish is a popular choice for the table, possessing a white, delicately flavored, firm flesh. They have a large bony head, a brick red body and fins (which pale to an orangish color after dying), large eyes, and are oil-rich.

Discovered in 1889, they weren't commercially fished until advances in technology allowed catching them in their deep water environment. They commonly are found at depths of from 800-1500 meters down.

Orange roughy reach an average length of 30-40 centimeters in length with some attaining 50 centimeters. They weight between .9-1.9 kilograms. If you're an American, as I am, you don't have a clue in hell what that means, but they taste great and really that's all that matters, isn't it?

It takes time, baby
The fish are slow to grow and slow to mature, not reaching reproductive age until 25-30 years. This, coupled with the female's comparatively small egg output, causes the fish to be susceptible to overfishing pressure. Stocks of orange roughy have declined since the early 90s and efforts have been made to restrict catches to allow them to repopulate. The fish enjoys an amazingly long life span of up to 150 years, and they do it without watching TV! Apparently they have a built in capability of not becoming bored, and we know they're not prolific reproducers, so basically they just swim about and grow old.

Life cycle and location
Orange roughy feed as small fish on zooplankton such as tiny shrimp and other crustaceans. Adults take smaller fish and squid as prey. They in turn are preyed upon by deep diving sharks, eels, hakes, and snake mackerels.

The fish are found worldwide with concentrations around New Zealand, Namibia, Chile, the northeast Atlantic Ocean, and the southern Indian Ocean. Fishing is most effective during the spawning season which is generally from late June to early August, when the fish congregate in large numbers to reproduce.

Orange roughy females release eggs into the water where the males fertilize them by ejecting sperm into the water. This method is not as effective as other methods of reproduction such as nest building fishes. It probably isn't all that much fun, either. The fertilized eggs float upward with hatching occuring in from 8-9 days. The larvae gradually descend, feeding and growing as they progress downward. It isn't known where the juvenile fish make their habitation as orange roughy aren't usually seen again until they fill the nets as adult fish.

Warning!
Several environmental watch groups list orange roughy on their watch lists of endangered species. The fish are slow to rebuild their stocks and some organizations recommend avoiding consuming orange roughy. Management techniques of deep sea species is in its infancy. Technology is just now revealing the factors of deep sea species which make management feasible. Many of the fisheries suffer declining production numbers after only a couple years of fishing. Restrictions on fishing is the only method known to allow the species to replenish itself. Orange roughy have shown little ability to be cultivated, probably due to its deep water habitat.

It's been pointed out that the next time you sit down to enjoy a meal of succulent orange roughy filet, that filet may well be older than your grandmother. Then again, while my grandmother was indeed white and somewhat flaky, she didn't possess the intrinsic delicacy and deliciousness of orange roughy. Life is a balancing act, isn't it? Perhaps it'd be alright to enjoy a little orange roughy and never to eat your grandmother, not even a little.

Nomenclature:
Kingdom- Animalia
Phylum- Chordata
Class- Actinopterygii
Order- Beryciformes
Family- Trachichthyidae
Genus- Hoplostethus
Species- H. atlanticus

Sources:
http://www.starfish.govt.nz/science/facts/fact-orange-roughy.htm#vital
http://www.mar-eco.no/learning-zone/backgrounders/
deepsea_life_forms/orange_roughy_story
http://www.mbayaq.org/cr/SeafoodWatch/web/sfw_factsheet.aspx?gid=14
http://en.wikipedia.org/wiki/Orange_roughy