The Molting Process in Golden King Crab
Dan Urban, NMFS Kodiak Lab Andrew Nault, Alaska Dept. of Fish & Game Golden King Crab Survey Locations
National Marine Fisheries Service, 1983-2016
-1,000m 546 fms
* Surveys only down to ~1,000m * Approx. 40,000 hauls with GKC Golden King Crab Fishery
Not showing 130 stat-areas where catch was confidential (less than 3 vessels or processors) Bering Sea/Aleutian Islands Fishery Value
Bering Sea Aleutian Other Halibut & S. Tanner GKC Sablefish $194 $25 Salmon $39 $194 $601 Bristol Bay Cod Red KC $213 Bering Sea $78 Snow Crab Pollock $124 $272 $466
Source: McDowell Group 2015 Source: REFM, Alaska Fish. Sci. Ctr. 2016
4 Golden King Crab Taxonomy Phylum Arthropoda
5 Golden King Crab Taxonomy Phylum Arthropoda
6 Golden King Crab Taxonomy Phylum Arthropoda
Alaskan Commercial Crustaceans
Red King crab Northern (pink) Shrimp Snow crab Blue King crab Sidestripe shrimp Southern Tanner crab Golden King crab Spot shrimp 7 Golden King Crab Taxonomy Phylum Arthropoda
Alaskan Commercial Crustaceans
Red King crab Northern (pink) Shrimp Snow crab Blue King crab Sidestripe shrimp Tanner crab Golden King crab Spot shrimp 8 Crustacean Molting Process
Four Major Molt Stages (Drach 1939)
PREMOLT MOLTING POSTMOLT INTERMOLT Swollen The process Shell hardening, Shell hardening, abdomen of molting other changes other changes
postmolt intermolt premolt molting 9 Why study the molting process?
Legal crab = last year’s surviving legals + new legals
Sublegal crab that Proportion New Legal crabs = molt to legal-size X that molt
Bristol Bay RKC model, SAFE 2016
10 Golden King Crab Molting
*Molting of adults considered asynchronous (Somerton & Otto 1986)
*In lab setting (58 males, 5-6 inches CL), there was a molting period. Golden King Crab Molting
Andy: KL holding setup
movie Acknowledgements
*F/V Atlantico
*Alaska Department of Fish & Game
*NMFS Staff at the Kodiak Lab.
13
15 Golden King Crab Molting
*Molting considered asynchronous (Somerton & Otto 1986)
*Data from fisheries observers and holding studies at the NMFS Kodiak
Lab.
*GKC were held at the KL as part of a tagging study • What was known about GKC molting?
*references: Otto & Cummiskey, AJ Paul, etc. *NMFS AI survey *ADF&G surveys, tagging *synchronous molting events video 18