Spider crab:professional buying guide, season, size, full or empty, auction prices

01

Buying sheet

Minimum size: Regulation (EU) 2019/1241, Annexes IV to VII; amended French order of 28 January 2013. Size grades: Regulation (EC) No 2406/96, Article 3. Tonnage and shares calculated by the editorial team from the sales declared at French fish auctions in 2024 (FranceAgriMer, workbook published on 2 July 2026). These figures only cover spider crab sold at auction, not spider crab sold by private agreement.

02

When to buy spider crab?

In spring. In 2024, French fish auctions sold 181 t in March, 204 t in April and 252 t in May, then 161 t in June. Landings then fall throughout the summer, down to 36 t in September, the lowest month of the year, before a small recovery from October to December (64 to 108 t a month). 2025 shows the same profile, with a spring peak and a low in September.

This rhythm is that of the fleet. Ifremer described inshore potters in the western Channel who set their pots for spider crab from March-April to July-August, with a maximum in May-June, and for lobster the rest of the year; at the end of summer, fishing effort on spider crab becomes almost nil.

03

Full or empty: how to choose a spider crab?

The spider crab grows by moulting for two or three years, then makes a last moult, called the terminal moult, after which it no longer grows (Ifremer). Just after it, the crab is "clear" ("claire") or "empty" ("vide"): its shell is new, but its flesh does not fill it yet. In the western Channel, these terminal moults take place from mid-July to October or November; in autumn, a large share of the spider crabs caught are therefore adults that have just moulted, and Ifremer saw this as the reason for their poor quality and low prices in October and November.

• Weight: at equal size, a full spider crab weighs markedly more. Weigh a few pieces from each batch in your hand.
• The shell: hard, not giving way under pressure. A soft shell signals a recent moult; these animals are fragile and die quickly.
• Liveliness: legs that react, no missing legs. A lifeless spider crab should be set aside.

These are trade clues. Cook and pick a few pieces per batch to know your real yield: no official source publishes a flesh yield for spider crab.

04

Spider crab, "crabe", "moussette": what are we talking about?

On the coast, names vary. Ifremer noted that east of Paimpol, from the Bay of Saint-Brieuc to Cap de la Hague, the spider crab is commonly called "crabe", often in the feminine ("une belle crabe"), whereas in lower Brittany "crabe" means the brown crab. The "moussette" is a young spider crab, not yet adult, sold under this name in the west of the Cotentin peninsula. Like any spider crab, it must measure at least 12 cm of shell to be landed. On a price list, ask for the species if the label leaves any doubt.

05

How to keep a spider crab alive?

Spider crab tolerates air much less well than brown crab or lobster. Seafish notes that it often dies in less than eight hours out of water, and that it must travel in water, in a vivier truck, even on a short journey; in a tank, it can be stored in several layers if the water is well aerated. For a restaurant or a fishmonger without a holding tank, the rule is therefore simple: have it delivered as close as possible to service and cook it the same day.

06

What to replace spider crab with?

07

What makes the price of spider crab move?

Year 2024, all French fish auctions: average first-sale price at the auction hall (FranceAgriMer, sales declared at fish auctions, workbook published on 2 July 2026). Spread between auctions: among those handling at least 5% of spider crab volumes. The auction price is not the price paid to the fish merchant: processing, transport and margin are added to it.

In 2024, the price did not follow landings month by month. The kilo was cheapest in January and November (about €1.50/kg, for 88 and 64 t), and not in May, the busiest month (252 t, about €1.80/kg). At the height of the season, producer organisations withdrew a notable share of landings from the market (17% of the volumes put up for sale in May, 22% in June), which probably supported prices. The price peaked at the end of summer, when landings collapse: about €2.50/kg in August (102 t), about €2.30/kg in September (36 t). 2025 shows the same profile, with August still the most expensive month and January the cheapest. The spread between auctions is wide: Le Croisic sells at more than twice the price of Erquy or Roscoff; size, selection of pieces and local outlets probably explain part of it, though no source allows that part to be measured.

• The season: low prices in January and in autumn, higher at the end of summer, when hardly anyone fishes for it any more.
• Fullness: in autumn, many spider crabs have just moulted and are empty; in the 1980s, Ifremer saw this as the first cause of the low prices of October and November.
• Withdrawals: in spring, a share of landings is withdrawn from the market by producer organisations.
• The holidays: from 1983 to 1987, Ifremer noted a price peak in December and at Easter; in 2024, December stayed close to the average (about €1.80/kg).
• Mortality: a product that dies quickly out of water costs money in vivier transport and losses, which the delivered price includes.