Did you know that nearly every (shark) family has got its longnose cousin? There is a longnose pygmy shark and a longnose spurdog. There are even a longsnout dogfish and a rough longnose shark in a family where all member have got a long snout anyway. There is a longnose sleeper shark: a species that unique that is hasn’t got a description or a scientific name yet.
But I want to introduce the longnose velvet dogfish (Centroselachus crepidater). It is a species of sleeper sharks and can be found in the eastern Atlantic, Indian Ocean and eastern and western Pacific. It lives on or near the bottom of continental and insular shelves.

Centroscymnus crepidater.jpg
By © Citron / , CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14679170

Reaching up to 4.3 ft -1.3 m- in length and 60 years in age, the longnose velvet dogfish matures at age 15 (males) and 22 (females). After a distinct pairing (with an embrace) the female gives birth to 3 to 9 living young (ovoviviparous).

Despite being fairly common and still classified as least concern by the IUCN, in view of its low productivity the increasing catch numbers (mostly bycatch by deep water trawl and hook and line fisheries, but more and more targeted, too) of the longnose velvet dogfish are cause for concern. It is used not only for fishmeal (to feed our increasing hunger for farmed salmon) and meat (fillets can retail for up to Aus$12/kg in Australia), but also for its liver oil and the squalene within.

Squalene or its saturated form squalane is used as an expensive ingredient in certain cosmetics from anti-aging creme to lip gloss, in squalene health capsules and as an adjuvant in vaccines. As a deep sea shark, the liver of the longnose velvet dogfish contains 61-73% squalene (by weight).
Although plant sources (primarily vegetable oils) are now used as well, Oceana estimated that between three and six million sharks annually are caught for their squalene. Some of them like the gulper shark are now endangered and protected by law (but pirates don’t care for the law).

Even if the longnose velvet dogfish isn’t endangered yet, Australia has been prohibited since 2002, that the liver lands unless the accompanying carcass is also landed (at least by the South East Trawl fishery). In the EU a similar regulation came into effect in 2003, only regarding shark fins (it seems that gutting should be banned like finning). A few years ago the mercury laws in Australia relaxed and allowed to use the meat of longnose velvet dogfish (since its flesh is high in methyl mercury) in addition to using the liver oil (convenient, isn’t it?). Normally I support the usage of all parts to prevent food waste, but in this case?

Sources: herehere and here

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