| 词条 | Carcinonemertes errans |
| 释义 |
| image = | image_caption = | regnum = Animalia | phylum = Nemertea | classis = Enopla | ordo = Monostilifera | familia = Carcinonemertidae | genus = Carcinonemertes | species = C. errans | binomial = Carcinonemertes errans | binomial_authority = Wickham, 1978[1] }} Carcinonemertes errans is a ribbon worm in the family Carcinonemertidae. It lives in symbiosis with the Dungeness crab (Metacarcinus magister), consuming the crab's developing eggs. In 1980 it was implicated in the collapse of the Dungeness crab fishery in central California. EcologyThe planktonic larva of the worm settles on a suitable crab host and encysts on the exoskeleton. Carcinonemertes errans is the first species in its genus to be found on a single host species. The worm has a permanent symbiotic relationship with its host crab but it is not a parasite as it does not feed directly on the crab but is instead an egg-predator. In male crabs, and in non-breeding female crabs, the worm may live in the axils of the limbs and encyst. After mating, the mature female crab stores the sperm for several months, before releasing a batch of fertilised eggs onto her abdomen, where she tucks them under the tail flap. At this stage, the ribbon worm migrates to the mass of eggs and feeds on the developing embryos.[2][3] If the worm larvae happen to settle on the exoskeleton of a brooding female crab, they can move immediately to the underside of the abdominal flap and metamorphose within 48 hours into juvenile worms. When settling, the larvae are gregarious, settling preferentially on already infected crabs.[3] It has been found that the worm is adversely affected by a lowering of the water salinity. Crabs in estuaries show an estuarine gradient, with crabs nearest the ocean carrying more worms than those further upstream.[4] Effect on the Dungeness crab industryThe Dungeness crab industry is an important fishery on the Pacific coast, with {{convert|53|e6lb|e6kg|abbr=off}} worth $170 million being harvested in 2014.[5] In 1980, the central California fishery was badly affected; Carcinonemertes errans was implicated, with 50% of the crabs' eggs produced each year being predated.[6] References1. ^{{cite WoRMS |author=Gibson, Raymond |year=2005 |title=Carcinonemertes errans Wickham, 1978 |id=156324 |accessdate=25 February 2019}} {{Taxonbar}}2. ^{{cite book|author=Light, Sol Felty |title=The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon |url=https://books.google.com/books?id=64jgZ1CfmB8C&pg=PA25 |year=2007 |publisher=University of California Press|isbn=978-0-520-23939-5 |page=25}} 3. ^{{cite journal |author=Dunn, Paul H. |author2=Young, Craig M. |year=2014 |title=Larval settlement of the nemertean egg predator Carcinonemertes errans on the Dungeness crab, Metacarcinus magister |journal=Invertebrate Biology |volume=133 |issue=3 |pages=210–212 |doi=10.1111/ivb.12059 }} 4. ^{{Cite journal|last=Dunn|first=Paul H.|last2=Young|first2=Craig M.|date=2013-12-20|title=Finding refuge: The estuarine distribution of the nemertean egg predator Carcinonemertes errans on the Dungeness crab, Cancer magister |url=http://www.sciencedirect.com/science/article/pii/S0272771413004538|journal=Estuarine, Coastal and Shelf Science|volume=135|pages=201–208|doi=10.1016/j.ecss.2013.10.012}} 5. ^{{cite web|title=Dungeness Crab Report 2014|url=http://www.psmfc.org/crab/2014-2015%20files/DUNGENESS%20CRAB%20REPORT2014.pdf|publisher=Pacific States Marine Fisheries Commission|accessdate=27 February 2019}} 6. ^1 {{cite journal |author=Wickham, Daniel E. |year=1980 |title=Aspects of the life history of Carcinonemertes errans (Nemertea: Carcinonemertidae), an egg predator of the crab Cancer magister |journal=Biological Bulletin |volume=159 |issue=1 |pages= 247–257|doi=10.2307/1541022 |url=https://www.researchgate.net/publication/242210070|jstor=1541022 }} 4 : Enopla|Animals described in 1978|Fauna of the Pacific Ocean|Parasites of crustaceans |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。