Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/31/2005
Publication Date: 9/30/2005
Citation: Chapman, J.C., Dumbauld, B.R., Smith, A. 2005. A preliminary look at the potential for using a parasitic isopod for augmentative biological control of its burrowing shrimp host. Annual Meeting of the Pacific Coast Shellfish Growers Association, September 26-29,2005, Hood River, OR.
Technical Abstract: An investigation of the life history and host-parasite ecology of a newly described bopyrid isopod (Orthione griffenis, Markham 2004) was initiated after discovering that mud shrimp (Upogebia pugettensis) populations along the West coast of the US were heavily infested with this parasite(>85% prevalence at some locations). Burrowing thalassinid shrimp cause oyster mortality in estuarine aquaculture operations and have been managed using the pesticide carbaryl for the last 40 years, primarily in Washington state coastal estuaries. The oyster aquaculture industry is currently searching for alternative methods to control shrimp. Since bopyrid isopods are known to cause sterility in host populations, they could represent a viable option for biological control. O. griffenis was present in 73% of the reproductively active U. pugettensis population in Yaquina Bay, Oregon and virtually 100% of the females which were infested with the isopod had not extruded eggs when sampled in January 2005. Allometric length-weight relationships suggest that both male and female parasitized hosts from 7 to 36% of their body mass to this parasite, which may have other effects on the host population. Reproductively active O griffenis were during the summer months (June-August) and larval stages were abundant in estuarine plankton samples. U. pugettensis could be artificially infected in the laboratory with the cryptoniscid stage collected from the plankton, but to date the intermediate host (typically a copepod) for the microniscus stage has not been found. Whether this information can be used to enhance the typically low infestation (<5%) of another bopyrid isopod (Ione cornuta) which infests ghost shrimp Neotrypaea californiensis is discussed.